Write Matrix to File

• Suppose we have a matrix that we want to write to a file. The following code snippet will do that.
  
  subroutine mat_w2f(mat,fname,N)
integer, intent(in) :: N
real(kind=8), intent(in), dimension(N,N) :: mat
character (len=*), intent(in) :: fname
integer :: i
open(unit=1,file=fname)
do i=1,N
do j=1,N
write(1,*), mat(i,j)
end do
end do
close(1)
end subroutine mat_w2f

  It simply writes each entry of a matrix to a line in the file.
  The reason for using len=* is that we have a variable string input.
  Note this is a simply hack to dump as an ASCII file. It's better to use a binary output (I use NetCDF)
• Formatted version
• Some references
  • passing a string as an argument when the dummy has specified length

Write Formatted Complex Number

• Suppose we want to output a nicely formatted complex number for output