program exf3 ! exf3.f90   example file  more complete structure, list, arrays, matrix

  integer, parameter :: n = 4   ! constant
  character (len=5) :: msg  = "short"  ! char for string
  character*4, dimension(3) ::  as = (/"abcd", "wxyz", "more"/)

  integer, dimension(n) ::  vec = (/1, 2, 4, 8/)     ! initialize an array, any type
  integer, dimension(4,3) :: mat = &
       reshape( (/1,2,3,4,5,6,7,8,9,10,11,12/), shape(mat))
                   ! 4 columns by 3 rows
  integer, dimension(100) ::  big            ! allocate space for 100 integers

  double precision, dimension(3) :: av = (/1.5, 2.2, 9.1/)
  double precision, dimension(5) :: small    ! space for 5 doubles
  double precision, dimension(4,3) :: matrix ! matrix 4 rows of 3 doubles
  double precision, dimension(0:3,0:2) :: cmat ! different subscript ranges

  matrix(4,3) = 1.0    ! subscripts start at 1  1,2,3,4  is 4 items normal   
  cmat(3,2) = 2.0      ! subscripts 0,1,2,3  0,1,2 per dimension
  
  print *, "exf3.f90 running"
  print *, "msg=", msg
  print *, "as(3)=", as(3)

  print *, "vec(1)=", vec(1)
  print *, "vec(n)=", vec(n)
  print *, "mat(4,3) is column major, row minor"
  print *, "mat(1,1)=", mat(1,1)
  print *, "mat(1,2)=", mat(1,2)
  print *, "mat(1,3)=", mat(1,3)
  print *, "mat(4,1)=", mat(4,1)
  print *, "mat(4,2)=", mat(4,2)
  print *, "mat(4,3)=", mat(4,3)

  print *, "av(3)=", av(3)
  cmat(0,0) = 1.0
  cmat(3,2) = 2.0
  print *, "cmac(0,0)=", cmat(0,0)
  print *, "cmac(3,2)=", cmat(3,2)
  
end program exf3