C4LIB
A Single Precision Complex Arithmetic Utility Library

C4LIB is a FORTRAN90 library which implements certain elementary functions for single precision complex (C4) variables.

The symbol "C4" is used to suggest a single precision complex variable. Here the 4 indicates that the underlying pair of real numbers each use 4 bytes of storage.

C4LIB contains routines that operate on scalars, vectors or doubly dimensioned arrays of C4's. A vector of C4's is denoted a C4VEC, and a doubly dimensioned array is a C4MAT.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

C4LIB is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.

Related Data and Programs:

BLAS1_C, a FORTRAN90 library which contains basic linear algebra routines for vector-vector operations, using single precision complex arithmetic.

C8LIB, a FORTRAN90 library which implements certain elementary functions for "C8" or double precision complex variables.

COMPLEX_NUMBERS, a FORTRAN90 program which demonstrates some simple features involved in the use of complex numbers in FORTRAN90 programming.

I4LIB, a FORTRAN90 library which contains many utility routines, using "I4" or "single precision integer" arithmetic.

I8LIB, a FORTRAN90 library which contains many utility routines, using "I8" or "double precision integer" arithmetic.

L4LIB, a FORTRAN90 library which contains many utility routines, using one byte logical (L4) variables.

LINPACK_C, a FORTRAN90 library which solves linear systems using single precision complex arithmetic;

R4LIB, a FORTRAN90 library which contains many utility routines, using "R4" or "single precision real" arithmetic.

R8LIB, a FORTRAN90 library which contains many utility routines, using "R8" or "double precision real" arithmetic.

Source Code:

• c4lib.f90, the source code.

Examples and Tests:

• c4lib_test.f90, a sample calling program.
• c4lib_test.txt, the output file.

List of Routines:

• C4_ABS evaluates the absolute value of a C4.
• C4_ACOS evaluates the inverse cosine of a C4.
• C4_ACOSH evaluates the inverse hyperbolic cosine of a C4.
• C4_ADD adds two C4's.
• C4_ARG returns the argument of a C4.
• C4_ASIN evaluates the inverse sine of a C4.
• C4_ASINH evaluates the inverse hyperbolic sine of a C4.
• C4_ATAN evaluates the inverse tangent of a C4.
• C4_ATANH evaluates the inverse hyperbolic tangent of a C4.
• C4_CONJ evaluates the conjugate of a C4.
• C4_COPY copies a C4.
• C4_COS evaluates the cosine of a C4.
• C4_COSH evaluates the hyperbolic cosine of a C4.
• C4_CUBE_ROOT returns the principal cube root of a C4.
• C4_DIV divides two C4's.
• C4_DIV_R4 divides a C4 by an R4.
• C4_EXP evaluates the exponential of a C4.
• C4_I returns the imaginary unit, i as a C4.
• C4_IMAG evaluates the imaginary part of a C4.
• C4_INV evaluates the inverse of a C4.
• C4_LE_L1 := X <= Y for C4 values, and the L1 norm.
• C4_LE_L2 := X <= Y for C4 values, and the L2 norm.
• C4_LE_LI := X <= Y for C4 values, and the L Infinity norm.
• C4_LOG evaluates the logarithm of a C4.
• C4_MAG returns the magnitude of a C4.
• C4_MUL multiplies two C4's.
• C4_NEG returns the negative of a C4.
• C4_NINT returns the nearest complex integer of a C4.
• C4_NORM_L1 evaluates the L1 norm of a C4.
• C4_NORM_L2 evaluates the L2 norm of a C4.
• C4_NORM_LI evaluates the L-infinity norm of a C4.
• C4_NORMAL_01 returns a unit pseudonormal C4.
• C4_ONE returns the value of 1 as a C4.
• C4_PRINT prints a C4.
• C4_REAL evaluates the real part of a C4.
• C4_SIN evaluates the sine of a C4.
• C4_SINH evaluates the hyperbolic sine of a C4.
• C4_SQRT returns the principal square root of a C4.
• C4_SUB subtracts two C4's.
• C4_SWAP swaps two C4's.
• C4_TAN evaluates the tangent of a C4.
• C4_TANH evaluates the hyperbolic tangent of a C4.
• C4_TO_CARTESIAN converts a C4 to Cartesian form.
• C4_TO_POLAR converts a C4 to polar form.
• C4_UNIFORM_01 returns a unit pseudorandom C4.
• C4_ZERO returns the value of 0 as a C4.
• C4MAT_ADD combines two C4MAT's with complex scalar factors.
• C4MAT_ADD_R4 combines two C4MAT's with real scalar factors.
• C4MAT_COPY copies a C4MAT.
• C4MAT_FSS factors and solves a system with multiple right hand sides.
• C4MAT_IDENTITY sets a C4MAT to the identity.
• C4MAT_INDICATOR returns the C4MAT indicator matrix.
• C4MAT_MINVM computes inverse(A) * B for C4MAT's.
• C4MAT_MM multiplies two C4MAT's.
• C4MAT_NINT rounds the entries of a C4MAT.
• C4MAT_NORM_FRO returns the Frobenius norm of a C4MAT.
• C4MAT_NORM_L1 returns the matrix L1 norm of a C4MAT.
• C4MAT_NORM_LI returns the matrix L-oo norm of a C4MAT.
• C4MAT_PRINT prints a C4MAT.
• C4MAT_PRINT_SOME prints some of a C4MAT.
• C4MAT_SCALE scales a C4MAT by a complex scalar factor.
• C4MAT_SCALE_R8 scales a C4MAT by a real scalar factor.
• C4MAT_UNIFORM_01 returns a unit pseudorandom C4MAT.
• C4MAT_ZERO zeroes a C4MAT.
• C4VEC_COPY copies a C4VEC.
• C4VEC_INDICATOR sets a C4VEC to the indicator vector.
• C4VEC_NINT rounds the entries of a C4VEC.
• C4VEC_NORM_L2 returns the L2 norm of a C4VEC.
• C4VEC_NORM_SQUARED returns the square of the L2 norm of a C4VEC.
• C4VEC_PRINT prints a C4VEC, with an optional title.
• C4VEC_PRINT_PART prints "part" of a C4VEC.
• C4VEC_PRINT_SOME prints some of a C4VEC.
• C4VEC_SORT_A_L1 ascending sorts a C4VEC by L1 norm.
• C4VEC_SORT_A_L2 ascending sorts a C4VEC by L2 norm.
• C4VEC_SORT_A_LI ascending sorts a C4VEC by L-infinity norm.
• C4VEC_SPIRAL returns N points on a spiral between C1 and C2.
• C4VEC_UNIFORM_01 returns a unit pseudorandom C4VEC.
• C4VEC_UNITY returns the N roots of unity.
• CARTESIAN_TO_C4 converts a Cartesian form to a C4.
• POLAR_TO_C4 converts a polar form to a C4.
• R4_CSQRT returns the complex square root of an R4.
• R4_FLOOR rounds an R4 "down" (towards -oo) to the nearest integral R4.
• R4_LOG_2 returns the logarithm base 2 of an R4.
• R8_UNIFORM_01 returns a unit pseudorandom R8.
• R4POLY2_ROOT returns the two roots of a quadratic polynomial.
• R4POLY3_ROOT returns the three roots of a cubic polynomial.
• R4POLY4_ROOT returns the four roots of a quartic polynomial.
• SORT_HEAP_EXTERNAL externally sorts a list of items into ascending order.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

You can go up one level to the FORTRAN90 source codes.