This is a generator of pseudo-random numbers using a linear congruential algorithm.
The program prn_congr receives one number (seed) and generates "m" pseudorandom numbers calculated with a linear congruential algorithm. These numbers will be put into raw_prn.dat .
The program prandom_points receives one number (seed) and generates "m" pseudorandom numbers calculated with a linear congruential algorithm. These numbers will be divided by "m", so that they are in the [0, 1) interval. After that, a file called points.data contains points (x, y) made by these pseudo-random numbers in that interval. To use this program, "m" must be even. If you wanted to use this programs with Schrage's algorithm, then "m" must be uneven.
The program schrage receives one number (seed) and generates "m-1" pseudorandom numbers calculated with Schrage's algorithm.
You can change the seed when the program executes. You can change the linear parameters of the algorithm in prn_mod.f90 . You can change the amount of prn that will be generated, "m", in prn_mod.f90 .
Recomended parameters are a=4, c=1 and m=9. Larger recomended parameters are m=6075, a=106 and c=1283, and m=12906, a=1741 and c=2731. An example of a bad choice would be a=1, c=2, m=7 and seed=0; because the actual period would be 4 instead of 7.
You'll need to install:
$ sudo apt-get update
$ sudo apt-get install gfortran
To compile:
$ gfortran -o <program name>.x prn_mod.f90 <program name>.f90
To execute:
$ ./<program name>.x
If you'd like to view the points, you can use gnuplot.
To install it:
$ sudo apt-get update
$ sudo apt-get install gnuplot-x11
Once in:
gnuplot> plot "points.dat" using 1:2
This will plot the data points using the first column as the x variable and the second, as the y variable.