Sherman-Morrison/tests/fMaponiA3_test_3x3_3.f90
2021-02-27 12:25:55 +01:00

60 lines
1.5 KiB
Fortran

program Interface_test
use Sherman_Morrison
implicit none
integer i, j !! Iterators
integer(c_int) :: Dim, N_updates
integer(c_int), dimension(:), allocatable :: Updates_index
real(c_double), dimension(:,:), allocatable :: A, S, Updates
real(c_double), dimension(:,:), allocatable :: S_inv
Dim = 3
N_updates = 3
allocate(Updates_index(Dim), A(Dim,Dim), S(Dim,Dim), Updates(Dim,Dim), S_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
do i=1,Dim
do j=1,Dim
write(*,"(F3.0,3X)", advance="no") A(i,j)
end do
write(*,*)
end do
write(*,*)
!! Prepare the diagonal matrix S and the update matrix Updates
do i=1,Dim
Updates_index(i) = i
do j=1,Dim
if (i == j) then
S(i,j) = A(i,j)
S_inv(i,j) = 1.0d0 / S(i,j)
else
S(i,j) = 0.0d0
S_inv(i,j) = 0.0d0
end if
Updates(i,j) = A(i,j) - S(i,j)
end do
end do
call MaponiA3(S_inv, Dim, N_updates, Updates, Updates_index)
do i=1,Dim
do j=1,Dim
write(*,"(F3.0,3X)", advance="no") S_inv(i,j)
end do
write(*,*)
end do
deallocate(Updates_index, A, S, Updates, S_inv)
end program