I am a beginner and need help in writing a small program. I am trying to generate random numbers in the range of [-1, 1] in gfortran in 2D. I know that in order to generate random numbers in the range of -1 and 1, I have to rescale the numbers to [0,2) but I am not getting right answer and also unable to figure out my mistake. Here is the code

program random
implicit none
real :: rnd
real, dimension (10,10) :: x
integer :: L, i, m, randomReal
L = 10 ! length of sequence
do i = 1, L
call random_number(rnd)
randomReal = 2*rnd-1
print *, "random real = ", randomReal


end do
write(*,*) (x(L,L), L=1,10) ! assign random numbers to array x
call random_number(x)
end program random

Here is what I get after executing

random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
random real = 0
0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 0.00000000E+00 6.72623263E-44 1.66754517E-43 0.00000000E+00 2.14721202E-38 0.00000000E+00

1 members found this post helpful.

You just described a problem, but you didn't mention what you've done already and which part of it is giving you problems. Specific answers require specific questions. For example, "Here is an excerpt of a program I've written, I expect it to do X but it's doing Y, here's the necessary debugging info, what am I missing?"

1 members found this post helpful.

Accept my appology, I have added my codes now.

Why are you declaring randomReal as an integer?
Also you're printing x before you fill it up.

I have declared randomReal to real now and have numbers listed below.

random real = 0.995119095
random real = 0.133649349
random real = 0.931830645
random real = 0.495855331
random real = -0.265218258
random real = -3.87262106E-02
random real = -0.852491498
random real = -0.989289641
random real = -0.305837512
random real = -0.315512419

and actually I am trying to figure out how to fill x. I multiply randomReal to x, but it gives me error. Thanks for pointing out my mistake.

@OP Kindly edit your posts (click on [Edit] button) and add [code] and [/code] tags around source-code.