Sherman-Morrison/Utils_mod.f90
François Coppens b2b4756b53 Problem solved. Problems was caused by reading the inverse matrix S_inv the same way as the matrix S, but apparently what has been stored is transpose(S_inv) and not S_inv. Therefore it needs to be read transposed compared to S in order to for S*S_inv to give the Identity matrix.
TODO: Calls from C/C++ are still broken because inside the MaponiA3 algo there is compensation for the fact that Fortran sends it's arrays in column-major order. This must be resolved by  transposeing S_inv before it is passed to MaponiA3 and remove the compensations made there.
2021-02-22 15:43:27 +01:00

56 lines
2.0 KiB
Fortran

module Utils
implicit none
contains
subroutine Read_dataset(filename, &
cycle_id, &
dim, &
n_updates, &
S, &
S_inv, &
Updates_index, &
Updates)
use, intrinsic :: iso_c_binding, only : c_int, c_double
implicit none
character (len = *), intent(in) :: filename
integer, intent(inout) :: cycle_id, dim, n_updates
integer(c_int), allocatable, intent(inout) :: Updates_index(:)
real(c_double), allocatable, intent(inout) :: S(:,:), S_inv(:,:)
real(c_double), allocatable, intent(inout) :: Updates(:,:)
integer :: i, j
character (len = 32) :: ignore
!! Start reading dataset from file
open(unit = 1000, file = filename)
read(1000,*)
read(1000,*) ignore, cycle_id
read(1000,*) ignore, dim
read(1000,*) ignore,n_updates
!! Initialise the arrays
allocate(Updates_index(n_updates), &
S(dim,dim), &
S_inv(dim,dim), &
Updates(dim,n_updates))
!! Read S and S_inv
read(1000,*)
do i=1,dim
do j=1,dim
!! For some reason S_inv needs to be read transposed &
! for S*S_inv to give the identity matrix
read(1000,*) ignore, ignore, S(i,j), S_inv(j,i)
end do
end do
!! Read Updates and Updates_index
do j=1,n_updates
read(1000,*) ignore, Updates_index(j)
do i=1,dim
read(1000,*) ignore, Updates(i,j)
end do
end do
!! End of reading the dataset from file
close(1000)
end subroutine Read_dataset
end module Utils