NORMAL
Normal Random Number Generators

NORMAL is a C library which returns a sequence of normally distributed pseudorandom numbers.

NORMAL is based on two simple ideas:

• the use of a fairly simple uniform pseudorandom number generator, which can be implemented in software;
• the use of the Box-Muller transformation to convert pairs of uniformly distributed random values to pairs of normally distributed random values.

Using these ideas, it is not too hard to generate normal sequences of real or complex values, of single or double precision. These values can be generated as single quantities, vectors or matrices. An associated seed actually determines the sequence. Varying the seed will result in producing a different sequence.

The fundamental underlying random number generator used here is based on a simple, old, and limited linear congruential random number generator originally used in the IBM System 360.

This library makes it possible to compare certain computations that use normal random numbers, written in C, C++, FORTRAN77, FORTRAN90, MATLAB or Python.

Licensing:

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

Languages:

NORMAL 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:

ASA183, a C library which implements the Wichman-Hill pseudorandom number generator.

C_RANDOM, C programs which illustrate the use of C's random number generator routines.

HAMMERSLEY, a C library which computes elements of a Hammersley Quasi Monte Carlo (QMC) sequence, using a simple interface.

LOG_NORMAL_TRUNCATED_AB, a C library which returns quantities associated with the log normal Probability Distribution Function (PDF) truncated to the interval [A,B].

RANDOM_SORTED, a C library which generates vectors of random values which are already sorted.

RANLIB, a C library which produces random samples from Probability Density Functions (PDF's), including Beta, Chi-square Exponential, F, Gamma, Multivariate normal, Noncentral chi-square, Noncentral F, Univariate normal, random permutations, Real uniform, Binomial, Negative Binomial, Multinomial, Poisson and Integer uniform, by Barry Brown and James Lovato.

RNGLIB, a C library which implements a random number generator (RNG) with splitting facilities, allowing multiple independent streams to be computed, by L'Ecuyer and Cote.

TRUNCATED_NORMAL, a C library which works with the truncated normal distribution over [A,B], or [A,+oo) or (-oo,B], returning the probability density function (PDF), the cumulative density function (CDF), the inverse CDF, the mean, the variance, and sample values.

UNIFORM, a C library which computes elements of a sequence of pseudorandom uniformly distributed values.

VAN_DER_CORPUT, a C library which computes elements of a 1D van der Corput Quasi Monte Carlo (QMC) sequence using a simple interface.

ZIGGURAT, a C library which computes elements of uniform, normal or exponential pseudorandom sequence using the ziggurat method.

Reference:

1. Paul Bratley, Bennett Fox, Linus Schrage,
   A Guide to Simulation,
   Second Edition,
   Springer, 1987,
   ISBN: 0387964673.
2. Bennett Fox,
   Algorithm 647: Implementation and Relative Efficiency of Quasirandom Sequence Generators,
   ACM Transactions on Mathematical Software,
   Volume 12, Number 4, December 1986, pages 362-376.
3. Donald Knuth,
   The Art of Computer Programming,
   Volume 2, Seminumerical Algorithms,
   Third Edition,
   Addison Wesley, 1997,
   ISBN: 0201896842.
4. Pierre LEcuyer,
   Random Number Generation,
   in Handbook of Simulation,
   edited by Jerry Banks,
   Wiley, 1998,
   ISBN: 0471134031,
   LC: T57.62.H37.
5. Peter Lewis, Allen Goodman, James Miller,
   A Pseudo-Random Number Generator for the System/360,
   IBM Systems Journal,
   Volume 8, 1969, pages 136-143.

Source Code:

• normal.c, the source code.
• normal.h, the include file.

Examples and Tests:

• normal_test.c, a sample calling program.
• normal_test.txt, the output file.

List of Routines:

• C4_NORMAL_01 returns a unit pseudonormal C4.
• C8_NORMAL_01 returns a unit pseudonormal C8.
• I4_NORMAL_AB returns a scaled pseudonormal I4.
• I8_NORMAL_AB returns a scaled pseudonormal I8.
• R4_NORMAL_01 returns a unit pseudonormal R4.
• R4_NORMAL_AB returns a scaled pseudonormal R4.
• R4_UNIFORM_01 returns a unit pseudorandom R4.
• R4MAT_PRINT prints an R4MAT.
• R4MAT_PRINT_SOME prints some of an R4MAT.
• R4VEC_PRINT prints an R4VEC.
• R4VEC_UNIFORM_01_NEW returns a unit pseudorandom R4VEC.
• R8_NORMAL_01 returns a unit pseudonormal R8.
• R8_NORMAL_AB returns a scaled pseudonormal R8.
• R8_UNIFORM_01 returns a unit pseudorandom R8.
• R8MAT_NORMAL_01 returns a unit pseudonormal R8MAT.
• R8MAT_NORMAL_01_NEW returns a unit pseudonormal R8MAT.
• R8MAT_NORMAL_AB returns a scaled pseudonormal R8MAT.
• R8MAT_NORMAL_AB_NEW returns a scaled pseudonormal R8MAT.
• R8MAT_PRINT prints an R8MAT.
• R8MAT_PRINT_SOME prints some of an R8MAT.
• R8VEC_NORMAL_01 returns a unit pseudonormal R8VEC.
• R8VEC_NORMAL_01_NEW returns a unit pseudonormal R8VEC.
• R8VEC_NORMAL_AB returns a scaled pseudonormal R8VEC.
• R8VEC_NORMAL_AB_NEW returns a scaled pseudonormal R8VEC.
• R8VEC_PRINT prints an R8VEC.
• R8VEC_UNIFORM_01_NEW returns a unit pseudorandom R8VEC.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

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