fortran index subroutine demo

Author: scivision

src/tests/read_slice.f90

@@ -0,0 +1,45 @@
+!! example of Fortran reading smaller array into slice of larger array via subroutine
+implicit none
+
+type :: foo
+integer :: i44(4,4)
+end type foo
+
+integer :: i, bigA(4,4)
+type(foo) :: B
+
+bigA = -1
+
+call getter(bigA(2:3,3:4))
+
+do i = 1,size(bigA,1)
+  print '(4I3)', bigA(i,:)
+enddo
+
+! ----
+
+B%i44 = -1
+
+call getter(B%i44(2:3,3:4))
+
+print *,''
+do i = 1,size(B%i44,1)
+  print '(4I3)', B%i44(i,:)
+enddo
+
+!! should print
+!! -1 -1 -1 -1
+!! -1 -1  1  2
+!! -1 -1  3  4
+!! -1 -1 -1 -1
+
+contains
+
+subroutine getter(A)
+integer, intent(out) :: A(2,2)
+
+A = reshape([1,2,3,4], shape(A), order=[2,1])
+
+end subroutine getter
+
+end program