Sherman-Morrison/fMaponiA3_test.f90

53 lines
1.4 KiB
Fortran

program Interface_test
use Sherman_Morrison, only : MaponiA3
use, intrinsic :: iso_c_binding, only : c_int, c_double
implicit none
integer i, j !! Iterators
integer(c_int) :: dim, N_updates
integer(c_int), dimension(:), allocatable :: Ar_index
real(c_double), dimension(:,:), allocatable :: A, A0, Ar
real(c_double), dimension(:,:), allocatable :: A0_inv
dim = 3
N_updates = 3
allocate(Ar_index(dim), A(dim,dim), A0(dim,dim), Ar(dim,dim), A0_inv(dim,dim))
!! Initialize A with M=3 and fill acc. to Eq. (17) from paper
A(1,1) = 1.0d0
A(1,2) = 1.0d0
A(1,3) = -1.0d0
A(2,1) = 1.0d0
A(2,2) = 1.0d0
A(2,3) = 0.0d0
A(3,1) = -1.0d0
A(3,2) = 0.0d0
A(3,3) = -1.0d0
!! Prepare the diagonal matrix A0 and the update matrix Ar
do i=1,dim
Ar_index(i) = i
do j=1,dim
if (i == j) then
A0(i,j) = A(i,j)
A0_inv(i,j) = 1.0d0 / A0(i,j)
else
A0(i,j) = 0.0d0
A0_inv(i,j) = 0.0d0
end if
Ar(i,j) = A(i,j) - A0(i,j)
end do
end do
call MaponiA3(A0, A0_inv, dim, n_updates, Ar, Ar_index)
do i=1,dim
do j=1,dim
write(*,"(F3.0,3X)", advance="no") A0_inv(i,j)
end do
write(*,*)
end do
deallocate(Ar_index, A, A0, Ar, A0_inv)
end program