# include # include # include # include # include # include using namespace std; # include "linpack_s.hpp" # include "blas0.hpp" # include "blas1_s.hpp" int main ( ); void test01 ( ); void test02 ( ); void test03 ( ); void test04 ( ); void test05 ( ); void test06 ( ); void test07 ( ); void test08 ( ); void test09 ( ); void test10 ( ); void test11 ( ); void test12 ( ); void test13 ( ); void test14 ( ); void test15 ( ); void test16 ( ); void test17 ( ); void test18 ( ); void test19 ( ); void test20 ( ); void test21 ( ); void test22 ( ); void sqrdc_test ( ); void sqrsl_test ( ); void test24 ( ); void test25 ( ); void test26 ( ); void test27 ( ); void ssvdc_test ( ); void test29 ( ); void test30 ( ); void test31 ( ); //****************************************************************************80 int main ( ) //****************************************************************************80 // // Purpose: // // MAIN is the main program for LINPACK_S_TEST. // // Discussion: // // LINPACK_S_TEST tests the LINPACK_S library. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 August 2016 // // Author: // // John Burkardt // { timestamp ( ); cout << "\n"; cout << "LINPACK_S_TEST\n"; cout << " C++ version\n"; cout << " Test the LINPACK_S library.\n"; test01 ( ); test02 ( ); test03 ( ); test04 ( ); test05 ( ); test06 ( ); test07 ( ); test08 ( ); test09 ( ); test10 ( ); test11 ( ); test12 ( ); test13 ( ); test14 ( ); test15 ( ); test16 ( ); test17 ( ); test18 ( ); test19 ( ); test20 ( ); test21 ( ); test22 ( ); sqrdc_test ( ); sqrsl_test ( ); test24 ( ); test25 ( ); test26 ( ); test27 ( ); ssvdc_test ( ); test29 ( ); test30 ( ); test31 ( ); // // Terminate. // cout << "\n"; cout << "LINPACK_S_TEST\n"; cout << " Normal end of execution.\n"; cout << "\n"; timestamp ( ); return 0; } //****************************************************************************80 void test01 ( ) //****************************************************************************80 // // Purpose: // // TEST01 tests SCHDC. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 4 # define LDA N float a[LDA*N]; float b[LDA*N]; int i; int info; int ipvt[N]; int j; int job; int k; float work[N]; cout << "\n"; cout << "TEST01\n"; cout << " For a general matrix,\n"; cout << " SCHDC computes the Cholesky decomposition.\n"; cout << "\n"; cout << " The number of equations is N = " << N << "\n"; // // Set the values of the matrix A. // for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= N; i++ ) { if ( i == j-1 ) { a[i-1+(j-1)*LDA] = -1.0; } else if ( i == j ) { a[i-1+(j-1)*LDA] = 2.0; } else if ( i == j+1 ) { a[i-1+(j-1)*LDA] = -1.0; } else { a[i-1+(j-1)*LDA] = 0.0; } } } cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // Decompose the matrix. // cout << "\n"; cout << " Decompose the matrix.\n"; job = 0; for ( i = 0; i < N; i++ ) { ipvt[i] = 0; } info = schdc ( a, LDA, N, work, ipvt, job ); if ( info != N ) { cout << "\n"; cout << " SCHDC returned INFO = " << info << "\n"; cout << " This means the matrix is not positive definite.\n"; return; } // // Zero out the lower diagonal. // for ( i = 2; i <= N; i++ ) { for ( j = 1; j <= i-1; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } // // Print the factorization. // cout << "\n"; cout << " The Cholesky factor U:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // Compute the Cholesky product. // for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { b[i-1+(j-1)*LDA] = 0.0; for ( k = 1; k <= N; k++ ) { b[i-1+(j-1)*LDA] = b[i-1+(j-1)*LDA] + a[k-1+(i-1)*LDA] * a[k-1+(j-1)*LDA]; } } } cout << "\n"; cout << " The product U' * U:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << b[i-1+(j-1)*LDA]; } cout << "\n"; } return; # undef LDA # undef N } //****************************************************************************80 void test02 ( ) //****************************************************************************80 // // Purpose: // // TEST02 tests SCHEX. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA N # define NZ 1 float a[LDA*N]; float b[LDA*N]; float c[N]; int i; int info; int ipvt[N]; int j; int job; int k; int l; float s[N]; int seed; float work[N]; float z[N]; cout << "\n"; cout << "TEST02\n"; cout << " For a general matrix,\n"; cout << " SCHEX can shift columns in a Cholesky factorization.\n"; cout << "\n"; cout << " The number of equations is N = " << N << "\n"; // // Set the values of the matrix A. // for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= N; i++ ) { if ( i == j-1 ) { a[i-1+(j-1)*LDA] = -1.0; } else if ( i == j ) { a[i-1+(j-1)*LDA] = 2.0; } else if ( i == j+1 ) { a[i-1+(j-1)*LDA] = -1.0; } else { a[i-1+(j-1)*LDA] = 0.0; } } } for ( i = 1; i <= N; i++ ) { z[i-1] = ( float ) i; } cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } cout << "\n"; cout << " The vector Z:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(12) << z[i-1]; } // // Decompose the matrix. // cout << "\n"; cout << " Decompose the matrix.\n"; job = 0; for ( i = 0; i < N; i++ ) { ipvt[i] = 0; } info = schdc ( a, LDA, N, work, ipvt, job ); if ( info != N ) { cout << "\n"; cout << " SCHDC returned INFO = " << info << "\n"; cout << " This means the matrix is not positive definite.\n"; return; } // // Zero out the lower diagonal. // for ( i = 2; i <= N; i++ ) { for ( j = 1; j <= i-1; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } // // Print the factorization. // cout << "\n"; cout << " The Cholesky factor U:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // Right circular shift columns L through K. // k = 1; l = 3; cout << "\n"; cout << " Right circular shift columns K = " << k << " through L = " << l << "\n"; job = 1; schex ( a, LDA, N, k, l, z, N, NZ, c, s, job ); // // Left circular shift columns K+1 through L. // cout << "\n"; cout << " Left circular shift columns K+1 = " << k+1 << " through L = " << l << "\n"; job = 2; schex ( a, LDA, N, k+1, l, z, N, NZ, c, s, job ); // // Print the factorization. // cout << "\n"; cout << " The shifted Cholesky factor U:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } cout << "\n"; cout << " The shifted vector Z:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(12) << z[i-1]; } // // Compute the Cholesky product. // for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { b[i-1+(j-1)*LDA] = 0.0; for ( k = 1; k <= N; k++ ) { b[i-1+(j-1)*LDA] = b[i-1+(j-1)*LDA] + a[k-1+(i-1)*LDA] * a[k-1+(j-1)*LDA]; } } } cout << "\n"; cout << " The shifted product U' * U:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << b[i-1+(j-1)*LDA]; } cout << "\n"; } return; # undef LDA # undef N # undef NZ } //****************************************************************************80 void test03 ( ) //****************************************************************************80 // // Purpose: // // TEST03 tests SCHUD. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define P 20 # define LDR P # define NZ 1 float b[P]; float beta[P]; float c[P]; int i; int info; int j; int job; float r[LDR*P]; float rho[NZ]; float row[P]; float s[P]; int seed; float x[P]; float y[NZ]; float z[P*NZ]; cout << "\n"; cout << "TEST03\n"; cout << " For a general matrix,\n"; cout << " SCHUD updates a Cholesky decomposition.\n"; cout << "\n"; cout << " In this example, we use SCHUD to solve a\n"; cout << " least squares problem R * b = z.\n"; cout << "\n"; cout << " The number of equations is P = " << P << "\n"; // // Initialize. // for ( j = 1; j <= P; j++ ) { for ( i = 1; i <= P; i++ ) { r[i-1+(j-1)*LDR] = 0.0; } } for ( j = 1; j <= NZ; j++ ) { for ( i = 1; i <= P; i++ ) { z[i-1+(j-1)*P] = 0.0; } } for ( i = 1; i <= P; i++ ) { x[i-1] = ( float ) i; } // // Use SCHUD to form R, Z and RHO by adding X and Y a row at a time. // X is a row of the least squares matrix and Y the right hand side. // seed = 123456789; for ( i = 1; i <= P; i++ ) { r4mat_uniform_01 ( 1, P, seed, row ); y[0] = 0.0; for ( j = 1; j <= P; j++ ) { y[0] = y[0] + row[j-1] * x[j-1]; } rho[0] = 0.0; schud ( r, LDR, P, row, z, P, NZ, y, rho, c, s ); } // // Generate the least squares solution, b = inverse ( R ) * Z. // for ( j = 1; j <= NZ; j++ ) { for ( i = 1; i <= P; i++ ) { b[i-1] = z[i-1+(j-1)*P]; } job = 01; info = strsl ( r, LDR, P, b, job ); cout << "\n"; cout << " Solution vector # " << j << "\n"; cout << " (Should be (1,2,3...,n))\n"; cout << "\n"; for ( i = 1; i <= P; i++ ) { if ( i <= 5 || P-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } } return; # undef LDR # undef NZ # undef P } //****************************************************************************80 void test04 ( ) //****************************************************************************80 // // Purpose: // // TEST04 tests SGBCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 10 # define ML 1 # define MU 1 # define LDA ( 2 * ML + MU + 1 ) float a[LDA*N]; int i; int ipivot[N]; int j; int m; float rcond; float z[N]; cout << "\n"; cout << "TEST04\n"; cout << " For a general banded matrix,\n"; cout << " SGBCO estimates the reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // m = ML + MU + 1; cout << " The bandwidth of the matrix is " << m << "\n"; for ( j = 1; j <= N; j++ ) { a[m-2+(j-1)*LDA] = -1.0; a[m-1+(j-1)*LDA] = 2.0; a[m +(j-1)*LDA] = -1.0; } // // Estimate the condition. // cout << "\n"; cout << " Estimate the condition.\n"; rcond = sgbco ( a, LDA, N, ML, MU, ipivot, z ); cout << "\n"; cout << " Estimated reciprocal condition = " << rcond << "\n"; return; # undef LDA # undef ML # undef MU # undef N } //****************************************************************************80 void test05 ( ) //****************************************************************************80 // // Purpose: // // TEST05 tests SGBFA and SGBSL. // // Discussion: // // The problem solved here is a larger version of this one: // // Matrix A is ( 2 -1 0 0 0) right hand side B is (1) // (-1 2 -1 0 0) (0) // ( 0 -1 2 -1 0) (0) // ( 0 0 -1 2 -1) (0) // ( 0 0 0 -1 2) (1) // // // Solution is (1) // (1) // (1) // (1) // (1) // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // // Local Parameters: // // N is the number of equations. // // ML is the number of subdiagonals, // MU the number of superdiagonals. // // LDA is the leading dimension of the array used to store the // matrix, which must be at least 2*ML+MU+1. // { # define N 10 # define ML 1 # define MU 1 # define LDA ( 2 * ML + MU + 1 ) float a[LDA*N]; float b[N]; int i; int info; int ipivot[N]; int j; int job; int m; cout << "\n"; cout << "TEST05\n"; cout << " For a general banded matrix,\n"; cout << " SGBFA computes the LU factors,\n"; cout << " SGBSL solves a factored linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the right hand side B. // b[0] = 1.0; for ( i = 2; i <= N-1; i++ ) { b[i-1] = 0.0; } b[N-1] = 1.0; // // Set the matrix A. // m = ML + MU + 1; cout << " The bandwidth of the matrix is " << m << "\n"; for ( j = 1; j <= N; j++ ) { a[m-2+(j-1)*LDA] = -1.0; a[m-1+(j-1)*LDA] = 2.0; a[m +(j-1)*LDA] = -1.0; } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sgbfa ( a, LDA, N, ML, MU, ipivot ); if ( info != 0 ) { cout << " Error! SGBFA returns INFO = " << info << "\n"; return; } // // Call SGBSL to solve the linear system. The solution // is returned in B, that is, it overwrites the right hand side. // cout << "\n"; cout << " Solve the linear system.\n"; job = 0; sgbsl ( a, LDA, N, ML, MU, ipivot, b, job ); // // Print the results. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,1,1,1,1,...,1,1))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef ML # undef MU # undef N } //****************************************************************************80 void test06 ( ) //****************************************************************************80 // // Purpose: // // TEST06 tests SGBFA and SGBDI. // // Discussion: // // Matrix A is ( 2 -1 0 0 0) // (-1 2 -1 0 0) // ( 0 -1 2 -1 0) // ( 0 0 -1 2 -1) // ( 0 0 0 -1 2) // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // // Local Parameters: // // N is the number of equations. // // ML is the number of subdiagonals, // MU the number of superdiagonals. // // LDA is the leading dimension of the array used to store the // matrix, which must be at least 2*ML+MU+1. // { # define N_MAX 128 # define ML 1 # define MU 1 # define LDA ( 2 * ML + MU + 1 ) float a[LDA*N_MAX]; float det[2]; int i; int ihi; int ilo; int info; int ipivot[N_MAX]; int j; int m; int n; int n_log; cout << "\n"; cout << "TEST06\n"; cout << " For a general banded matrix,\n"; cout << " SGBFA factors the matrix,\n"; cout << " SGBDI computes the determinant as\n"; cout << " det = MANTISSA * 10^EXPONENT\n"; cout << "\n"; cout << " Find the determinant of the -1,2,-1 matrix\n"; cout << " for N = 2, 4, 8, 16, 32, 64, 128.\n"; cout << "\n"; cout << " (For this matrix, det ( A ) = N + 1.)\n"; // // Set the matrix A. // m = ML + MU + 1; cout << " The bandwidth of the matrix is " << m << "\n"; cout << "\n"; cout << " N Mantissa Exponent\n"; cout << "\n"; n = 1; for ( n_log = 1; n_log <= 7; n_log++ ) { n = 2 * n; for ( j = 1; j <= n; j++ ) { for ( i = 1; i <= LDA; i++ ) { a[i-1+(j-1)*LDA] = 0.0; } } for ( j = 1; j <= n; j++ ) { i = j; a[i-j+ML+MU+(j-1)*LDA] = 2.0; } for ( j = 2; j <= n; j++ ) { i = j - 1; a[i-j+ML+MU+(j-1)*LDA] = -1.0; } for ( j = 1; j <= n-1; j++ ) { i = j + 1; a[i-j+ML+MU+(j-1)*LDA] = -1.0; } info = sgbfa ( a, LDA, n, ML, MU, ipivot ); if ( info != 0 ) { cout << " Error! SGBFA returns INFO = " << info << "\n"; return; } sgbdi ( a, LDA, n, ML, MU, ipivot, det ); cout << " " << setw(6) << n << " " << setw(14) << det[0] << " " << setw(14) << det[1] << "\n"; } return; # undef LDA # undef ML # undef MU # undef N_MAX } //****************************************************************************80 void test07 ( ) //****************************************************************************80 // // Purpose: // // TEST07 tests SGBFA and SGBSL. // // Discussion: // // SGBFA and SGBSL are for general banded matrices. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 # define ML 25 # define MU 25 # define LDA ( 2 * ML + MU + 1 ) float a[LDA*N]; float b[N]; int i; int ihi; int ilo; int info; int ipivot[N]; int j; int job; int m; float temp; cout << "\n"; cout << "TEST07\n"; cout << " For a general banded matrix,\n"; cout << " SGBFA computes the LU factors,\n"; cout << " SGBSL solves a factored linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to matrix A and right hand side B. // // We want to try a problem with a significant bandwidth. // m = ML + MU + 1; cout << " The bandwidth of the matrix is " << m << "\n"; for ( j = 1; j <= N; j++ ) { ilo = i4_max ( 1, j - MU ); ihi = i4_min ( N, j + ML ); temp = 0.0; for ( i = ilo; i <= ihi; i++ ) { a[i-j+m-1+(j-1)*LDA] = -1.0; temp = temp - 1.0; } temp = temp + 1.0; a[m-1+(j-1)*LDA] = 4.0 - temp; b[j-1] = 4.0; } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sgbfa ( a, LDA, N, ML, MU, ipivot ); if ( info != 0 ) { cout << " Error! SGBFA returns INFO = " << info << "\n"; return; } // // Call SGBSL to solve the linear system. The solution // is returned in B, that is, it overwrites the right hand side. // cout << "\n"; cout << " Solve the linear system.\n"; job = 0; sgbsl ( a, LDA, N, ML, MU, ipivot, b, job ); // // Print the results. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,1,1,1,1,...,1,1))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef ML # undef MU # undef N } //****************************************************************************80 void test08 ( ) //****************************************************************************80 // // Purpose: // // TEST08 calls SGECO and SGESL. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // // Local Parameters: // // LDA defines the maximum matrix size we will use. // { # define LDA 10 float a[LDA*LDA]; float b[LDA]; int i; int ipvt[LDA]; int job; int n; float rcond; float z[LDA]; n = 3; cout << "\n"; cout << "TEST08\n"; cout << " For a general matrix,\n"; cout << " SGECO computes the LU factors and computes\n"; cout << " its reciprocal condition number;\n"; cout << " SGESL solves a factored linear system.\n"; cout << " The matrix size is N = " << n << "\n"; // // Set the values of the matrix A. // a[0+0*LDA] = 1.0; a[0+1*LDA] = 2.0; a[0+2*LDA] = 3.0; a[1+0*LDA] = 4.0; a[1+1*LDA] = 5.0; a[1+2*LDA] = 6.0; a[2+0*LDA] = 7.0; a[2+1*LDA] = 8.0; a[2+2*LDA] = 0.0; // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; rcond = sgeco ( a, LDA, n, ipvt, z ); cout << " The reciprocal matrix condition number = " << rcond << "\n"; if ( rcond + 1.0 == 1.0 ) { cout << " Error! The matrix is nearly singular!\n"; return; } // // Set a right hand side. // b[0] = 6.0; b[1] = 15.0; b[2] = 15.0; // // Solve the linear system. // cout << "\n"; cout << " Solve the linear system.\n"; job = 0; sgesl ( a, LDA, n, ipvt, b, job ); // // Print the results. // cout << "\n"; cout << " Solution returned by SGESL\n"; cout << " (Should be (1,1,1))\n"; cout << "\n"; for ( i = 1; i <= n; i++ ) { cout << " " << setw(14) << b[i-1] << "\n"; } // // A second right hand side can be solved without refactoring a. // cout << "\n"; cout << " Call SGESL for a new right hand\n"; cout << " side for the same, factored matrix.\n"; // // Set the right hand side. // b[0] = 1.0; b[1] = 4.0; b[2] = 7.0; // // Solve the system. // cout << "\n"; cout << " Solve a linear system.\n"; job = 0; sgesl ( a, LDA, n, ipvt, b, job ); // // Print the results. // cout << "\n"; cout << " Solution returned by SGESL\n"; cout << " (should be (1,0,0))\n"; cout << "\n"; for ( i = 1; i <= n; i++ ) { cout << " " << setw(14) << b[i-1] << "\n"; } // // The transposed problem A'*X = B can be solved by SGESL // as well, without any refactoring. // cout << "\n"; cout << " Call SGESL for transposed problem.\n"; // // Set the right hand side. // b[0] = 6.0; b[1] = 6.0; b[2] = -3.0; // // Solve the transposed system. // cout << "\n"; cout << " Call SGESL to solve a transposed linear system.\n"; job = 1; sgesl ( a, LDA, n, ipvt, b, job ); // // Print the results. // cout << "\n"; cout << " Solution returned by SGESL\n"; cout << " (should be (-1,0,1))\n"; cout << "\n"; for ( i = 1; i <= n; i++ ) { cout << " " << setw(14) << b[i-1] << "\n"; } return; # undef LDA } //****************************************************************************80 void test09 ( ) //****************************************************************************80 // // Purpose: // // TEST09 tests SGEFA and SGEDI. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 3 # define LDA 3 // // Matrix listed by columns. // float a[LDA*N] = { 1.0, 4.0, 7.0, 2.0, 5.0, 8.0, 3.0, 6.0, 0.0 }; float det[2]; int i; int info; int ipvt[N]; int j; int job; float work[N]; cout << "\n"; cout << "TEST09\n"; cout << " For a general banded matrix,\n"; cout << " SGEFA computes the LU factors;\n"; cout << " SGEDI computes the inverse and determinant.\n"; cout << " The matrix size is N = " << N << "\n"; // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sgefa ( a, LDA, N, ipvt ); if ( info != 0 ) { cout << " Error! The matrix is nearly singular!\n"; return; } // // Get the inverse and determinant. // cout << "\n"; cout << " Get the inverse and determinant.\n"; job = 11; sgedi ( a, LDA, N, ipvt, det, work, job ); cout << "\n"; cout << " The determinant = " << det[0] << " * 10^"<< det[1] << "\n"; cout << "\n"; cout << " The inverse matrix:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } return; # undef LDA # undef N } //****************************************************************************80 void test10 ( ) //****************************************************************************80 // // Purpose: // // TEST10 tests SGEFA and SGESL. // // Discussion: // // Solve A*x = b where A is a given matrix, and B a right hand side. // // We will also assume that A is stored in the simplest // possible way. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 3 # define LDA N // // The entries of the matrix A are listed by columns. // float a[LDA*N] = { 1.0, 4.0, 7.0, 2.0, 5.0, 8.0, 3.0, 6.0, 0.0 }; float b[N] = { 6.0, 15.0, 15.0 }; int i; int info; int ipvt[N]; int j; int job; cout << "\n"; cout << "TEST10\n"; cout << " For a general banded matrix,\n"; cout << " SGEFA computes the LU factors;\n"; cout << " SGESL solves a factored linear system;\n"; cout << "\n"; cout << " The number of equations is N = " << N << "\n"; cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(14) << a[i-1+(j-1)*LDA]; } cout << "\n"; } cout << "\n"; cout << " The right hand side B:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(14) << b[i-1]; } cout << "\n"; // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sgefa ( a, LDA, N, ipvt ); if ( info != 0 ) { cout << " SGEFA returned an error flag INFO = " << info << "\n"; return; } // // Solve the system. // job = 0; sgesl ( a, LDA, N, ipvt, b, job ); cout << "\n"; cout << " SGESL returns the solution:\n"; cout << " (Should be (1,1,1))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(14) << b[i-1]; } cout << "\n"; return; # undef N # undef LDA } //****************************************************************************80 void test11 ( ) //****************************************************************************80 // // Purpose: // // TEST11 tests SGEFA and SGESL. // // Discussion: // // In this example, we solve a relatively large linear system. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 # define LDA N float a[LDA*N]; float b[N]; int i; int info; int ipvt[N]; int j; int job; cout << "\n"; cout << "TEST11\n"; cout << " For a general banded matrix,\n"; cout << " SGEFA computes the LU factors;\n"; cout << " SGESL solves a factored linear system;\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to the matrix A and the right hand side B. // // The problem is just an enlarged version of the // problem for N = 5, which is: // // Matrix A is ( n -1 -1 -1 -1) Right hand side B is (1) // (-1 n -1 -1 -1) (1) // (-1 -1 n -1 -1) (1) // (-1 -1 -1 n -1) (1) // (-1 -1 -1 -1 n) (1) // // Solution is (1) // (1) // (1) // (1) // (1) // for ( i = 1; i <= N; i++ ) { b[i-1] = 1.0; } for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= N; i++ ) { if ( i == j ) { a[i-1+(j-1)*LDA] = ( float ) N; } else { a[i-1+(j-1)*LDA] = -1.0; } } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sgefa ( a, LDA, N, ipvt ); if ( info != 0 ) { cout << " SGEFA returned an error flag INFO = " << info << "\n"; return; } // // Solve the system. // cout << "\n"; cout << " Solve the factored system.\n"; job = 0; sgesl ( a, LDA, N, ipvt, b, job ); // // Print the results. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,1,1,1,1,...,1,1))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef N } //****************************************************************************80 void test12 ( ) //****************************************************************************80 // // Purpose: // // TEST12 tests SGTSL. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 float b[N]; float c[N]; float d[N]; float e[N]; int i; int info; cout << "\n"; cout << "TEST12\n"; cout << " For a general tridiagonal matrix,\n"; cout << " SGTSL factors and solves a linear system.\n"; cout << " The matrix size is N = " << N << "\n"; cout << "\n"; // // Set up the linear system, by storing the values of the // subdiagonal, diagonal, and superdiagonal in C, D, and E, // and the right hand side in B. // c[0] = 0.0; for ( i = 2; i <= N; i++ ) { c[i-1] = -1.0; } for ( i = 1; i <= N; i++ ) { d[i-1] = 2.0; } for ( i = 1; i <= N-1; i++ ) { e[i-1] = -1.0; } e[N-1] = 0.0; for ( i = 1; i <= N-1; i++ ) { b[i-1] = 0.0; } b[N-1] = ( float ) ( N + 1 ); // // Factor the matrix and solve the system. // cout << "\n"; cout << " Factor the matrix and solve the system.\n"; info = sgtsl ( N, c, d, e, b ); if ( info != 0 ) { cout << "\n"; cout << " SGTSL returns nonzero INFO = " << info << "\n"; return; } // // Print the results. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef N } //****************************************************************************80 void test13 ( ) //****************************************************************************80 // // Purpose: // // TEST13 tests SPBCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 10 # define LDA 2 float a[LDA*N]; int i; int info; int j; int m; float rcond; float z[N]; cout << "\n"; cout << "TEST13\n"; cout << " For a positive definite symmetric banded matrix,\n"; cout << " SPBCO estimates the reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the number of nonzero diagonals. // m = 1; // // Set the value of the subdiagonal and diagonal. // for ( j = 1; j <= N; j++ ) { a[0+(j-1)*LDA] = -1.0; a[1+(j-1)*LDA] = 2.0; } cout << "\n"; cout << " Estimate the condition.\n"; rcond = spbco ( a, LDA, N, m, z ); cout << "\n"; cout << " Reciprocal condition = " << rcond << "\n"; return; # undef LDA # undef N } //****************************************************************************80 void test14 ( ) //****************************************************************************80 // // Purpose: // // TEST14 tests SPBDI. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N_MAX 128 # define LDA 2 float a[LDA*N_MAX]; float det[2]; int i; int info; int j; int m; int n; int n_log; cout << "\n"; cout << "TEST14\n"; cout << " For a positive definite symmetric banded matrix,\n"; cout << " SPBDI computes the determinant as\n"; cout << " det = MANTISSA * 10^EXPONENT\n"; cout << "\n"; cout << " Find the determinant of the -1,2,-1 matrix\n"; cout << " for N = 2, 4, 8, 16, 32, 64, 128.\n"; cout << "\n"; cout << " (For this matrix, det ( A ) = N + 1.)\n"; // // Set the number of nonzero diagonals. // m = 1; cout << "\n"; cout << " N Mantissa Exponent\n"; cout << "\n"; n = 1; for ( n_log = 1; n_log <= 7; n_log++ ) { n = 2 * n; a[0+0*LDA] = 0.0; for ( j = 2; j <= n; j++ ) { a[0+(j-1)*LDA] = -1.0; } for ( j = 1; j <= n; j++ ) { a[1+(j-1)*LDA] = 2.0; } info = spbfa ( a, LDA, n, m ); if ( info != 0 ) { cout << " Error! SPBFA returns INFO = " << info << "\n"; return; } spbdi ( a, LDA, n, m, det ); cout << " " << setw(6) << n << " " << setw(14) << det[0] << " " << setw(14) << det[1] << "\n"; } return; # undef LDA # undef N_MAX } //****************************************************************************80 void test15 ( ) //****************************************************************************80 // // Purpose: // // TEST15 tests SPBFA and SPBSL. // // Discussion: // // SPBFA and SPBSL are for a positive definite symmetric band matrix. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 10 # define LDA 2 float a[LDA*N]; float b[N]; int i; int info; int j; int m; cout << "\n"; cout << "TEST15\n"; cout << " For a positive definite symmetric banded matrix,\n"; cout << " SPBFA computes the LU factors.\n"; cout << " SPBSL solves a factored linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to matrix A and right hand side B. // // The problem is just an enlarged version of the // problem for N = 5, which is: // // Matrix A is ( 2 -1 0 0 0) right hand side B is (1) // (-1 2 -1 0 0) (0) // ( 0 -1 2 -1 0) (0) // ( 0 0 -1 2 -1) (0) // ( 0 0 0 -1 2) (1) // // // solution is (1) // (1) // (1) // (1) // (1) // // Set the right hand side. // b[0] = 1.0; for ( i = 2; i <= N-1; i++ ) { b[i-1] = 0.0; } b[N-1] = 1.0; // // Set the number of nonzero diagonals. // m = 1; // // Set the value of the subdiagonal and diagonal. // for ( j = 1; j <= N; j++ ) { a[0+(j-1)*LDA] = -1.0; a[1+(j-1)*LDA] = 2.0; } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = spbfa ( a, LDA, N, m ); if ( info != 0 ) { cout << " Error! SPBFA returns INFO = " << info << "\n"; return; } // // Solve the linear system. // cout << "\n"; cout << " Solve the linear system.\n"; spbsl ( a, LDA, N, m, b ); // // Print the results. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,1,1,1,1,...,1,1))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef N } //****************************************************************************80 void test16 ( ) //****************************************************************************80 // // Purpose: // // TEST16 tests SPOCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA N float a[LDA*N]; int i; int info; int j; int job; float rcond; float z[N]; cout << "\n"; cout << "TEST16\n"; cout << " For a positive definite symmetric banded matrix,\n"; cout << " SPOCO estimates the reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // for ( j = 0; j < N; j++ ) { for ( i = 0; i < N; i++ ) { a[i+j*LDA] = 0.0; } } for ( i = 1; i <= N; i++ ) { a[i-1+(i-1)*LDA] = 2.0; if ( 1 < i ) { a[i-1+(i-2)*LDA] = -1.0; } if ( i < N ) { a[i-1+(i)*LDA] = -1.0; } } cout << "\n"; cout << " Estimate the condition.\n"; rcond = spoco ( a, LDA, N, z ); cout << "\n"; cout << " Reciprocal condition = " << rcond << "\n"; return; # undef LDA # undef N } //****************************************************************************80 void test17 ( ) //****************************************************************************80 // // Purpose: // // TEST17 tests SPOFA and SPODI. // // Discussion: // // SPOFA factors a positive definite symmetric matrix, // and SPODI can compute the determinant or the inverse. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA N float a[LDA*N]; float det[2]; int i; int info; int j; int job; cout << "\n"; cout << "TEST17\n"; cout << " For a positive definite symmetric matrix,\n"; cout << " SPOFA computes the LU factors.\n"; cout << " SPODI computes the inverse or determinant.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // for ( j = 0; j < N; j++ ) { for ( i = 0; i < N; i++ ) { a[i+j*LDA] = 0.0; } } for ( i = 1; i <= N; i++ ) { a[i-1+(i-1)*LDA] = 2.0; if ( 1 < i ) { a[i-1+(i-2)*LDA] = -1.0; } if ( i < N ) { a[i-1+(i)*LDA] = -1.0; } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = spofa ( a, LDA, N ); if ( info != 0 ) { cout << " Error, SPOFA returns INFO = " << info << "\n"; return; } // // Invert the matrix. // cout << "\n"; cout << " Get the determinant and inverse.\n"; job = 11; spodi ( a, LDA, N, det, job ); // // Print the results. // cout << "\n"; cout << " Determinant = " << det[0] << " * 10^" << det[1] << "\n"; // // SPODI produces only the 'upper half triangle' of the inverse, // which is actually symmetric. Thus, the lower half could be // produced by copying from the upper half. However, the first row // of A, as returned, is exactly the first row of the inverse. // cout << "\n"; cout << " First row of inverse:\n"; cout << "\n"; for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[0+(j-1)*LDA]; } cout << "\n"; return; # undef LDA # undef N } //****************************************************************************80 void test18 ( ) //****************************************************************************80 // // Purpose: // // TEST18 tests SPOFA and SPOSL. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 20 # define LDA N float a[LDA*N]; float b[N]; int i; int info; int j; int job; float x[N]; cout << "\n"; cout << "TEST18\n"; cout << " For a positive definite symmetric matrix,\n"; cout << " SPOFA computes the LU factors.\n"; cout << " SPOSL solves a factored linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // for ( j = 0; j < N; j++ ) { for ( i = 0; i < N; i++ ) { a[i+j*LDA] = 0.0; } } for ( i = 1; i <= N; i++ ) { a[i-1+(i-1)*LDA] = 2.0; if ( 1 < i ) { a[i-1+(i-2)*LDA] = -1.0; } if ( i < N ) { a[i-1+(i)*LDA] = -1.0; } } // // Set the right hand side. // for ( i = 1; i <= N; i++ ) { x[i-1] = ( float ) i; } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; for ( j = 1; j <= N; j++ ) { b[i-1] = b[i-1] + a[i-1+(j-1)*LDA] * x[j-1]; } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = spofa ( a, LDA, N ); if ( info != 0 ) { cout << " Error, SPOFA returns INFO = " << info << "\n"; return; } // // Solve the linear system. // sposl ( a, LDA, N, b ); // // Print the result. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef N } //****************************************************************************80 void test19 ( ) //****************************************************************************80 // // Purpose: // // TEST19 tests SPPCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 float a[(N*(N+1))/2]; int i; int j; int k; float rcond; float z[N]; cout << "\n"; cout << "TEST19\n"; cout << " For a positive definite symmetric packed matrix,\n"; cout << " SPPCO estimates the reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; if ( i == j - 1 ) { a[k-1] = -1.0; } else if ( i == j ) { a[k-1] = 2.0; } else { a[k-1] = 0.0; } } } // // Estimate the condition. // cout << "\n"; cout << " Estimate the condition number.\n"; rcond = sppco ( a, N, z ); cout << "\n"; cout << " Reciprocal condition number = " << rcond << "\n"; return; # undef N } //****************************************************************************80 void test20 ( ) //****************************************************************************80 // // Purpose: // // TEST20 tests SPPFA and SPPDI. // // Discussion: // // SPPFA factors a packed positive definite symmetric matrix, // and SPPDI can compute the determinant or the inverse. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 float a[(N*(N+1))/2]; float b[N*N]; float det[2]; int i; int info; int j; int job; int k; cout << "\n"; cout << "TEST20\n"; cout << " For a positive definite symmetric packed matrix,\n"; cout << " SPPFA computes the LU factors.\n"; cout << " SPPDI computes the inverse or determinant.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; if ( i == j - 1 ) { a[k-1] = -1.0; } else if ( i == j ) { a[k-1] = 2.0; } else { a[k-1] = 0.0; } } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sppfa ( a, N ); if ( info != 0 ) { cout << "\n"; cout << " Error, SPPFA returns INFO = " << info << "\n"; return; } // // Invert the matrix. // cout << "\n"; cout << " Get the determinant and inverse.\n"; job = 11; sppdi ( a, N, det, job ); // // Print the results. // cout << "\n"; cout << " Determinant = " << det[0] << " * 10^" << det[1] << "\n"; // // SPPDI produces only the 'upper half triangle' of the inverse, // which is actually symmetric. Thus, the lower half could be // produced by copying from the upper half. However, the first row // of A, as returned, is exactly the first row of the inverse. // k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; b[i-1+(j-1)*N] = a[k-1]; b[j-1+(i-1)*N] = a[k-1]; } } cout << "\n"; cout << " The inverse matrix:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << b[i-1+(j-1)*N]; } cout << "\n"; } return; # undef N } //****************************************************************************80 void test21 ( ) //****************************************************************************80 // // Purpose: // // TEST21 tests SPPFA and SPPSL. // // Discussion: // // SPOFA factors a positive definite symmetric matrix, // and SPOSL can solve a factored linear system. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 20 float a[(N*(N+1))/2]; float b[N]; int i; int info; int j; int job; int k; float x[N]; cout << "\n"; cout << "TEST21\n"; cout << " For a positive definite symmetric packed matrix,\n"; cout << " SPPFA computes the LU factors.\n"; cout << " SPPSL solves a factored linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // for ( i = 1; i <= N; i++ ) { x[i-1] = ( float ) i; } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; } // // Set the matrix A. // k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; if ( i == j - 1 ) { a[k-1] = -1.0; b[i-1] = b[i-1] + a[k-1] * x[j-1]; b[j-1] = b[j-1] + a[k-1] * x[i-1]; } else if ( i == j ) { a[k-1] = 2.0; b[i-1] = b[i-1] + a[k-1] * x[i-1]; } else { a[k-1] = 0.0; } } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n"; info = sppfa ( a, N ); if ( info != 0 ) { cout << "\n"; cout << " Error, SPPFA returns INFO = " << info << "\n"; return; } // // Solve the linear system. // sppsl ( a, N, b ); // // Print the result. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef N } //****************************************************************************80 void test22 ( ) //****************************************************************************80 // // Purpose: // // TEST22 tests SPTSL. // // Discussion: // // SPTSL factors and solves a positive definite symmetric tridiagonal system. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 20 float b[N]; float d[N]; float e[N]; int i; float x[N]; cout << "\n"; cout << "TEST22\n"; cout << " For a positive definite symmetric tridiagonal matrix,\n"; cout << " SPTSL factors and solves a linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Set the matrix A. // for ( i = 1; i <= N; i++ ) { x[i-1] = ( float ) i; } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; } for ( i = 1; i <= N; i++ ) { d[i-1] = 2.0; } for ( i = 1; i <= N-1; i++ ) { e[i-1] = -1.0; } e[N-1] = 0.0; for ( i = 1; i <= N; i++ ) { if ( 1 < i ) { b[i-1] = b[i-1] + e[i-2] * x[i-2]; } b[i-1] = b[i-1] + d[i-1] * x[i-1]; if ( i < N ) { b[i-1] = b[i-1] + e[i-1] * x[i]; } } // // Factor and solve the system. // cout << "\n"; cout << " Factor the matrix and solve the system.\n"; sptsl ( N, d, e, b ); // // Print the result. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef N } //****************************************************************************80 void sqrdc_test ( ) //****************************************************************************80 // // Purpose: // // SQRDC_TEST tests SQRDC. // // Discussion: // // SQRDC computes the QR factorization. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 3 # define P 3 # define LDA N float a[LDA*P] = { 1.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 1.0 }; float b[LDA*P]; int i; int info; int ipvt[P]; int j; int job; int k; float q[N*N]; float qraux[P]; float qty[N]; float qy[N]; float r[N*P]; float rsd[N]; float work[P]; float xb[N]; float y[N]; cout << "\n"; cout << "SQRDC_TEST\n"; cout << " SQRDC computes the QR decomposition of a rectangular\n"; cout << " matrix, but does not return Q and R explicitly.\n"; cout << "\n"; cout << " Show how Q and R can be recovered using SQRSL.\n"; // // Print the matrix A. // cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // Decompose the matrix. // cout << "\n"; cout << " Decompose the matrix.\n"; job = 0; for ( j = 1; j <= P; j++ ) { ipvt[j] = 0; } sqrdc ( a, LDA, N, P, qraux, ipvt, work, job ); // // Print out what SQRDC has stored in A... // cout << "\n"; cout << " The packed matrix A which describes Q and R:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // ...and in QRAUX. // cout << "\n"; cout << " The QRAUX vector, containing some additional\n"; cout << " information defining Q:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(12) << qraux[i-1]; } cout << "\n"; // // Print out the resulting R factor. // for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { if ( j < i ) { r[i-1+(j-1)*N] = 0.0; } else { r[i-1+(j-1)*N] = a[i-1+(j-1)*LDA]; } } } cout << "\n"; cout << " The R factor:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { cout << " " << setw(12) << r[i-1+(j-1)*LDA]; } cout << "\n"; } // // Call SQRSL to extract the information about the Q matrix. // We do this, essentially, by asking SQRSL to tell us the // value of Q*Y, where Y is a column of the identity matrix. // job = 10000; for ( i = 1; i <= N; i++ ) { // // Set the vector Y. // for ( j = 1; j <= N; j++ ) { y[j-1] = 0.0; } y[i-1] = 1.0; // // Ask SQRSL to tell us what Q*Y is. // info = sqrsl ( a, LDA, N, P, qraux, y, qy, qty, b, rsd, xb, job ); if ( info != 0 ) { cout << " Error! SQRSL returns INFO = " << info << "\n"; return; } // // Copy QY into the appropriate column of Q. // for ( j = 1; j <= N; j++ ) { q[j-1+(i-1)*N] = qy[j-1]; } } // // Now print out the Q matrix we have extracted. // cout << "\n"; cout << " The Q factor:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << q[i-1+(j-1)*N]; } cout << "\n"; } // // Compute Q*R to verify that it equals A. // for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { b[i-1+(j-1)*LDA] = 0.0; for ( k = 1; k <= N; k++ ) { b[i-1+(j-1)*LDA] = b[i-1+(j-1)*LDA] + q[i-1+(k-1)*N] * r[k-1+(j-1)*N]; } } } // // Print the result. // cout << "\n"; cout << " The product Q * R:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= P; j++ ) { cout << " " << setw(12) << b[i-1+(j-1)*LDA]; } cout << "\n"; } return; # undef LDA # undef N # undef P } //****************************************************************************80 void sqrsl_test ( ) //****************************************************************************80 // // Purpose: // // SQRSL_TEST tests SQRSL. // // Discussion: // // SQRSL can solve a linear system that was factored by SQRDC. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 28 August 2016 // // Author: // // John Burkardt // { # define N 5 # define P 3 # define LDA N float a[LDA*P] = { 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 2.0, 3.0, 4.0, 5.0, 1.0, 4.0, 9.0, 16.0, 25.0 }; float b[P]; float b2[P] = { -3.02, 4.4914286, -0.72857143 }; int i; int info; int ipvt[N]; int j; int job; float qraux[P]; float qty[N]; float qy[N]; float r[N]; float work[P]; float xb[N]; float y[N] = { 1.0, 2.3, 4.6, 3.1, 1.2 }; cout << "\n"; cout << "SQRSL_TEST\n"; cout << " SQRSL solves a rectangular linear system A*x=b in the\n"; cout << " least squares sense after A has been factored by SQRDC.\n"; cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 0; i < N; i++ ) { for ( j = 0; j < P; j++ ) { cout << " " << setw(12) << a[i+j*LDA]; } cout << "\n"; } // // Decompose the matrix. // cout << "\n"; cout << " Decompose the matrix.\n"; job = 0; for ( j = 0; j < P; j++ ) { ipvt[j] = 0; } sqrdc ( a, LDA, N, P, qraux, ipvt, work, job ); // // Call SQRSL to compute the least squares solution A*x=b. // job = 110; info = sqrsl ( a, LDA, N, P, qraux, y, qy, qty, b, r, xb, job ); if ( info != 0 ) { cerr << "\n"; cerr << "SQRSL_TEST - Warning!\n"; cerr << " SQRSL returns INFO = " << info << "\n"; return; } cout << "\n"; cout << " X X(expected):\n"; cout << "\n"; for ( i = 0; i < P; i++ ) { cout << " " << setw(14) << b[i] << " " << setw(14) << b2[i] << "\n"; } return; # undef LDA # undef N # undef P } //****************************************************************************80 void test24 ( ) //****************************************************************************80 // // Purpose: // // TEST24 tests SSICO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 # define LDA N float a[LDA*N]; int i; int ipvt[N]; int j; float rcond; float z[N]; cout << "\n"; cout << "TEST24\n"; cout << " SSICO estimates the reciprocal condition number.\n"; cout << " for a symmetric indefinite matrix.\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to the matrix A and the right hand side B. // for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { if ( i == j ) { a[i-1+(j-1)*LDA] = 2.0; } else if ( j == i+1 ) { a[i-1+(j-1)*LDA] = -1.0; } else { a[i-1+(j-1)*LDA] = 0.0; } } } // // Estimate the condition. // cout << "\n"; cout << " Estimate the condition.\n"; rcond = ssico ( a, LDA, N, ipvt, z ); cout << "\n"; cout << " Estimated reciprocal condition = " << rcond << "\n"; return; } //****************************************************************************80 void test25 ( ) //****************************************************************************80 // // Purpose: // // TEST25 tests SSIFA and SSISL. // // Discussion: // // SSIFA and SSISL are for symmetric indefinite matrices. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 # define LDA N float a[LDA*N]; float b[N]; int i; int info; int ipvt[N]; int j; cout << "\n"; cout << "TEST25\n"; cout << " For a symmetric indefinite matrix,\n"; cout << " SSIFA factor a symmetric indefinite matrix;\n"; cout << " SSISL solves a factored linear system,\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to the matrix A and the right hand side B. // for ( i = 1; i < N; i++ ) { b[i-1] = 0.0; } b[N-1] = ( float ) ( N + 1 ); for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { if ( i == j ) { a[i-1+(j-1)*LDA] = 2.0; } else if ( j == i+1 ) { a[i-1+(j-1)*LDA] = -1.0; } else { a[i-1+(j-1)*LDA] = 0.0; } } } // // Factor the matrix A. // cout << "\n"; cout << " Factor the matrix.\n"; info = ssifa ( a, LDA, N, ipvt ); if ( info != 0 ) { cout << " Error! SSIFA returns INFO = " << info << "\n"; return; } // // Solve the linear system. // cout << "\n"; cout << " Solve the linear system.\n"; ssisl ( a, LDA, N, ipvt, b ); // // Print the result. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef LDA # undef N } //****************************************************************************80 void test26 ( ) //****************************************************************************80 // // Purpose: // // TEST26 tests SSPCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 float a[(N*(N+1))/2]; int i; int ipvt[N]; int j; int k; float rcond; float z[N]; cout << "\n"; cout << "TEST26\n"; cout << " For a symmetric indefinite packed matrix,\n"; cout << " SSPCO estimates the reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to the matrix A. // k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; if ( i == j ) { a[k-1] = 2.0; } else if ( j == i+1 ) { a[k-1] = -1.0; } else { a[k-1] = 0.0; } } } // // Estimate the condition. // cout << "\n"; cout << " Estimate the condition.\n"; rcond = sspco ( a, N, ipvt, z ); cout << "\n"; cout << " Estimated reciprocal condition = " << rcond << "\n"; return; # undef N } //****************************************************************************80 void test27 ( ) //****************************************************************************80 // // Purpose: // // TEST27 tests SSPFA and SSPSL. // // Discussion: // // SSPFA and SSPSL are for packed symmetric indefinite matrices. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 100 float a[(N*(N+1))/2]; float b[N]; int i; int info; int ipvt[N]; int j; int k; cout << "\n"; cout << "TEST27\n"; cout << " For a symmetric indefinite packed matrix,\n"; cout << " SSPFA computes the LU factors,\n"; cout << " SSPSL solves a factored linear system,\n"; cout << " The matrix size is N = " << N << "\n"; // // Assign values to the matrix A and the right hand side B. // for ( i = 1; i <= N-1; i++ ) { b[i-1] = 0.0; } b[N-1] = ( float ) ( N + 1 ); k = 0; for ( j = 1; j <= N; j++ ) { for ( i = 1; i <= j; i++ ) { k = k + 1; if ( i == j ) { a[k-1] = 2.0; } else if ( j == i+1 ) { a[k-1] = -1.0; } else { a[k-1] = 0.0; } } } // // Factor the matrix. // cout << "\n"; cout << " Factor the matrix.\n" << flush; info = sspfa ( a, N, ipvt ); if ( info != 0 ) { cout << " Error! SSPFA returns INFO = " << info << "\n"; return; } // // Solve the linear system. // cout << "\n"; cout << " Solve the linear system.\n" << flush; sspsl ( a, N, ipvt, b ); // // Print the result. // cout << "\n"; cout << " The first and last 5 entries of solution:\n"; cout << " (Should be (1,2,3,4,5,...,n-1,n))\n" << flush; cout << "\n"; for ( i = 1; i <= N; i++ ) { if ( i <= 5 || N-5 < i ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } if ( i == 5 ) { cout << " ...... ..............\n"; } } return; # undef N } //****************************************************************************80 void ssvdc_test ( ) //****************************************************************************80 // // Purpose: // // SSVDC_TEST tests SSVDC. // // Discussion: // // SSVDC computes the singular value decomposition: // // A = U * S * V' // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define M 6 # define N 4 float a[M*N]; float b[M*N]; // // S should be dimensioned at least max ( M+1, N ). // float e[M+N]; int i; int info; int j; int job; int k; int lda; int ldu; int ldv; // // S should be dimensioned at least max ( M+1, N ). // float s[M+N]; int seed; float sigma[M*N]; float u[M*M]; float v[N*N]; float work[M]; cout << "\n"; cout << "SSVDC_TEST\n"; cout << " For an MxN matrix A in general storage,\n"; cout << " SSVDC computes the singular value decomposition:\n"; cout << " A = U * S * V'\n"; cout << "\n"; cout << " Matrix rows M = " << M << "\n"; cout << " Matrix columns N = " << N << "\n"; // // Set A. // seed = 123456789; r4mat_uniform_01 ( M, N, seed, a ); cout << "\n"; cout << " The matrix A:\n"; cout << "\n"; for ( i = 1; i <= M; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(10) << a[(i-1)+(j-1)*M]; } cout << "\n"; } // // Decompose the matrix. // cout << "\n"; cout << " Decompose the matrix.\n"; job = 11; lda = M; ldu = M; ldv = N; info = ssvdc ( a, lda, M, N, s, e, u, ldu, v, ldv, work, job ); if ( info != 0 ) { cout << "\n"; cout << "SSVDC_TEST - Warning:\n"; cout << " SSVDC returned nonzero INFO = " << info << "\n"; return; } cout << "\n"; cout << " Singular values:\n"; cout << "\n"; for ( i = 1; i <= i4_min ( M, N ); i++ ) { cout << " " << setw(4) << i+1 << " " << setw(14) << s[i-1] << "\n"; } cout << "\n"; cout << " Left Singular Vector Matrix U:\n"; cout << "\n"; for ( i = 1; i <= M; i++ ) { for ( j = 1; j <= M; j++ ) { cout << " " << setw(10) << u[(i-1)+(j-1)*M]; } cout << "\n"; } cout << "\n"; cout << " Right Singular Vector Matrix V:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(10) << v[(i-1)+(j-1)*N]; } cout << "\n"; } for ( i = 1; i <= M; i++ ) { for ( j = 1; j <= N; j++ ) { if ( i == j ) { sigma[(i-1)+(j-1)*M] = s[i-1]; } else { sigma[(i-1)+(j-1)*M] = 0.0; } } } // // Verify that A = U * S * V'. // for ( i = 1; i <= M; i++ ) { for ( k = 1; k <= N; k++ ) { b[(i-1)+(k-1)*M] = 0.0; for ( j = 1; j <= N; j++ ) { b[(i-1)+(k-1)*M] = b[(i-1)+(k-1)*M] + sigma[i-1+(j-1)*M] * v[k-1+(j-1)*N]; } } } for ( i = 1; i <= M; i++ ) { for ( k = 1; k <= N; k++ ) { a[(i-1)+(k-1)*M] = 0.0; for ( j = 1; j <= M; j++ ) { a[(i-1)+(k-1)*M] = a[(i-1)+(k-1)*M] + u[i-1+(j-1)*M] * b[j-1+(k-1)*M]; } } } cout << "\n"; cout << " The product U * S * V' (should equal A):\n"; cout << "\n"; for ( i = 1; i <= M; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(10) << a[(i-1)+(j-1)*M]; } cout << "\n"; } return; # undef M # undef N } //****************************************************************************80 void test29 ( ) //****************************************************************************80 // // Purpose: // // TEST29 tests STRCO. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA N float a[LDA*N]; int i; int j; int job; float rcond; int seed = 123456789; float z[N]; cout << "\n"; cout << "TEST29\n"; cout << " For a triangular matrix,\n"; cout << " STRCO computes the LU factors and\n"; cout << " computes its reciprocal condition number.\n"; cout << " The matrix size is N = " << N << "\n"; // // Lower triangular matrix A. // r4mat_uniform_01 ( LDA, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = i+1; j <= N; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } cout << "\n"; cout << " Lower triangular matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } job = 0; rcond = strco ( a, LDA, N, z, job ); cout << "\n"; cout << " The reciprocal condition number = " << rcond << "\n"; // // Upper triangular matrix A. // r4mat_uniform_01 ( LDA, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= i-1; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } cout << "\n"; cout << " Upper triangular matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } job = 1; rcond = strco ( a, LDA, N, z, job ); cout << "\n"; cout << " The reciprocal condition number = " << rcond << "\n"; return; # undef LDA # undef N } //****************************************************************************80 void test30 ( ) //****************************************************************************80 // // Purpose: // // TEST30 tests STRDI. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA N float a[LDA*N]; float det[2]; int i; int info; int j; int job; int seed = 123456789; cout << "\n"; cout << "TEST30\n"; cout << " For a triangular matrix,\n"; cout << " STRDI computes the determinant or inverse.\n"; cout << " The matrix size is N = " << N << "\n"; // // Lower triangular matrix A. // r4mat_uniform_01 ( N, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = i+1; j <= N; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } cout << "\n"; cout << " Lower triangular matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } job = 110; info = strdi ( a, LDA, N, det, job ); cout << "\n"; cout << " The determinant = " << det[0] << " * 10^(" << det[1] << ").\n"; cout << "\n"; cout << " The inverse matrix:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } // // Upper triangular matrix A. // r4mat_uniform_01 ( N, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= i-1; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } cout << "\n"; cout << " Upper triangular matrix A:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } job = 111; info = strdi ( a, LDA, N, det, job ); cout << "\n"; cout << " The determinant = " << det[0] << " * 10^(" << det[1] << ").\n"; cout << "\n"; cout << " The inverse matrix:\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= N; j++ ) { cout << " " << setw(12) << a[i-1+(j-1)*LDA]; } cout << "\n"; } return; # undef LDA # undef N } //****************************************************************************80 void test31 ( ) //****************************************************************************80 // // Purpose: // // TEST31 tests STRSL. // // Discussion: // // STRSL solves triangular linear systems. // // Licensing: // // This code is distributed under the GNU LGPL license. // // Modified: // // 23 June 2009 // // Author: // // John Burkardt // { # define N 5 # define LDA 5 float a[LDA*N]; float b[N]; int i; int info; int j; int job; int seed = 123456789; float x[N]; cout << "\n"; cout << "TEST31\n"; cout << " For a triangular matrix,\n"; cout << " STRSL solves a linear system.\n"; cout << " The matrix size is N = " << N << "\n"; // // Lower triangular matrix A. // r4mat_uniform_01 ( N, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = i+1; j <= N; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } for ( i = 1; i <= N; i++) { x[i-1] = ( float ) ( i ); } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; for ( j = 1; j <= N; j++ ) { b[i-1] = b[i-1] + a[i-1+(j-1)*LDA] * x[j-1]; } } cout << "\n"; cout << " For a lower triangular matrix A,\n"; cout << " solve A * x = b\n"; job = 00; info = strsl ( a, LDA, N, b, job ); cout << "\n"; cout << " The solution (should be 1,2,3,4,5):\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; for ( j = 1; j <= N; j++ ) { b[i-1] = b[i-1] + a[j-1+(i-1)*LDA] * x[j-1]; } } cout << "\n"; cout << " For a lower triangular matrix A,\n"; cout << " solve A' * x = b\n"; job = 10; info = strsl ( a, LDA, N, b, job ); cout << "\n"; cout << " The solution (should be 1,2,3,4,5):\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } // // Upper triangular matrix A. // r4mat_uniform_01 ( N, N, seed, a ); for ( i = 1; i <= N; i++ ) { for ( j = 1; j <= i-1; j++ ) { a[i-1+(j-1)*LDA] = 0.0; } } for ( i = 1; i <= N; i++) { x[i-1] = ( float ) ( i ); } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; for ( j = 1; j <= N; j++ ) { b[i-1] = b[i-1] + a[i-1+(j-1)*LDA] * x[j-1]; } } cout << "\n"; cout << " For an upper triangular matrix A,\n"; cout << " solve A * x = b\n"; job = 01; info = strsl ( a, LDA, N, b, job ); cout << "\n"; cout << " The solution (should be 1,2,3,4,5):\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } for ( i = 1; i <= N; i++ ) { b[i-1] = 0.0; for ( j = 1; j <= N; j++ ) { b[i-1] = b[i-1] + a[j-1+(i-1)*LDA] * x[j-1]; } } cout << "\n"; cout << " For an upper triangular matrix A,\n"; cout << " solve A' * x = b\n"; job = 11; info = strsl ( a, LDA, N, b, job ); cout << "\n"; cout << " The solution (should be 1,2,3,4,5):\n"; cout << "\n"; for ( i = 1; i <= N; i++ ) { cout << " " << setw(6) << i << " " << setw(14) << b[i-1] << "\n"; } return; # undef LDA # undef N }