Functions/Subroutines
real(kind=default_precision) function, public	random (idum)
	returns a scalar random number, the initial seed idum must be negative usage: idum = -k !(set idum < 0 to initialise) do i=1,nvals my_rand(i) = random(idum) end do More...

Variables
integer, parameter	k4b =selected_int_kind(9)

integer(k4b), parameter	ia =16807

integer(k4b), parameter	im =2147483647

integer(k4b), parameter	iq =127773

integer(k4b), parameter	ir =2836

Function/Subroutine Documentation

◆ random()

real(kind=default_precision) function, public maths_mod::random ( integer(k4b), intent(inout) idum )

returns a scalar random number, the initial seed idum must be negative usage: idum = -k !(set idum < 0 to initialise) do i=1,nvals my_rand(i) = random(idum) end do

Parameters

idum	Initial seed which must be negative

Definition at line 23 of file maths.F90.

     integer(k4b),intent(inout) :: idum
         
     real,save :: am
     integer(k4b), save :: ix=-1,iy=-1,k
 
     if (idum <=0 .or. iy < 0) then
       am = nearest(1.0,-1.0)/im
       iy=ior(ieor(888889999,abs(idum)),1)
       ix=ieor(777755555,abs(idum))
       idum=abs(idum)+1
     end if
     ix = ieor(ix,ishft(ix,13))
     ix = ieor(ix,ishft(ix,-17))
     ix = ieor(ix,ishft(ix,5))
     k=iy/iq
     iy=ia*(iy-k*iq)-ir*k
     if(iy < 0) iy = iy + im
     random = am*ior(iand(im,ieor(ix,iy)),1)