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Section Arrays: Matrix¶

Adapted from: https://github.com/gjbex/Fortran-MOOC/tree/master/source_code/arrays

This program demonstrates a 2D matrix in Fortran.¶

program matrix
  implicit none
  integer, parameter :: ROWS = 3, COLS = 5
  real, dimension(ROWS, COLS) :: A
  integer :: i, j
  real :: total

  A = reshape([ (((i - 1)*size(A, 2) + j, j=1,size(A, 2)), i=1,size(A, 1)) ], &
              shape(A))
  do i = 1, size(A, 1)
      print *, A(i, :)
  end do
  total = 0.0
  do j = 1, size(A, 2)
      do i = 1, size(A, 1)
          total = total + A(i, j)**2
      end do
  end do
  print '(/, A, F10.2)', 'total = ', total
end program matrix

The above program is compiled and run using Fortran Package Manager (fpm):

Build the Program using FPM (Fortran Package Manager)¶

import os
root_dir = os.getcwd()

code_dir = root_dir + "/" + "Fortran_Code/Section_Arrays_Matrix"

os.chdir(code_dir)

build_status = os.system("fpm build 2>/dev/null")

Run the Program using FPM (Fortran Package Manager)¶

exec_status = os.system("fpm run 2>/dev/null")

   1.00000000       4.00000000       7.00000000       10.0000000       13.0000000    
   2.00000000       5.00000000       8.00000000       11.0000000       14.0000000    
   3.00000000       6.00000000       9.00000000       12.0000000       15.0000000    

total =    1240.00