uniform, a FORTRAN90 code which returns a sequence of uniformly distributed pseudorandom numbers.
The fundamental underlying random number generator is based on a simple, old, and limited linear congruential random number generator originally used in the IBM System 360. If you want state of the art random number generation, look elsewhere!
FORTRAN90 already has the random_number function, which can return pseudorandom numbers rapidly, in bulk, and generally with less correlation than UNIFORM provides.
However, this library makes it possible to compare certain computations that use uniform random numbers, written in C, C++, FORTRAN77, FORTRAN90, Mathematica, MATLAB or Python.
Various types of random data can be computed. The routine names are chosen to indicate the corresponding type:
In some cases, a one dimensional vector or two dimensional array of values is to be generated, and part of the name will therefore include:
The underlying random numbers are generally defined over some unit interval or region. Routines are available which return these "unit" values, while other routines allow the user to specify limits between which the unit values are rescaled. The name of a routine will usually include a tag suggestig which is the case:
The random number generator embodied here is not very sophisticated. It will not have the best properties of distribution, noncorrelation and long period. It is not the purpose of this library to achieve such worthy goals. This is simply a reasonably portable library that can be implemented in various languages, on various machines, and for which it is possible, for instance, to regard the output as a function of the seed, and moreover, to work directly with the sequence of seeds, if necessary.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
uniform is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and a Python version.
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NORMAL, a FORTRAN90 code which computes elements of a sequence of pseudorandom normally distributed values.
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RANDOM_MPI, a FORTRAN90 code which demonstrates one way to generate the same sequence of random numbers for both sequential execution and parallel execution under MPI.
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