program VectorExamples
! This file:
! http://ftp.aset.psu.edu/pub/ger/fortran/hdk/VectorSubscripts.f90
!
! Vector-valued subscript example 1.
! by Arjen Markus <arjen.markus@wldelft.nl>
! as posted at comp.lang.fortran.
   implicit none

   integer, parameter            :: n1 = 20
   integer, parameter            :: n2 = 20

   integer, dimension(1:n1,1:n2) :: new_excitation

   integer                       :: i1, i2, i
   integer, dimension(1:3)       :: iv1, iv2, a,b,c
   !
   ! Testing the meaning of vector-valued subscripts for
   ! two-dimensional arrays ...
   !
   iv1 = (/ 1, 2, 3 /)
   iv2 = (/ 1, 2, 3 /)
   new_excitation = -1
   do i2 = 1,3
      do i1 = 1,3
         new_excitation(i1,i2) = i1 * 10 + i2
! Michael Metcalf's note: new_excitation(::2, ::2), for example, is
! also valid. That is,strides of 2 and 2 yield the 100 elements:
! (1,1),(1,3), ... (1,n1-1), (3,1),(3,3), ... (3,n1-1), ...
! (n2-1,1) (n2-1,3) ... (n2-1,n1-1).
!
      enddo
   enddo
   print *, new_excitation(::2,::2)

   print *, new_excitation(iv1,iv2)

! Vector Subscript Example 2
! by Christoph Arns  and Aidan Heerdegen
! as posted at comp.lang.fortran.

a = (/ 1, 2, 3 /)
b = (/ 1, 2, 3 /)
if (all(a==b)) print *,"a and b are the same!"
print *, "a=",a
do i=1,3
 c(i)=10*i
 b(i)=i
end do
print *,  "Vector c(b)=",c(b)
! Output:
!
!          11          31          -1          -1          -1          -1
!          -1          13          33          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1          -1          -1          -1          -1          -1
!          -1
!          11          21          31          12          22          32
!a and b are the same!
!a=           1           2           3
!Vector c(b)=          10          20          30

end program VectorExamples