Those files are accessed write-only,gsal said:Your program uses two external files, you did not provide them.
!cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
! CODE TO SOLVE DIFFUSION EQUATION USING SHERMAN-MORRISON METHOD
! Df= diffusion co-eff, delt and delx are grid spacing of time
! and space in discretized equations.
do k=1,T
do i=1,L
p(i)=x(i)
! write(*,*) p(i)
enddo
call DGESV( L, nhrs, A, L, pivot, p, L, OK )
do i=1,L
x(i)=p(i)
! write(*,*) p(i)
enddo
enddo
write(*,*) OK