The correlation matrix in this question means a corref.xx file.
Use the following fortran program to read the matrix.
::::fortran
program main
integer, parameter :: d = 1396
real(8) :: x(d, d)
integer :: i, j
open (unit = 10, file = "corref.01", form = "UNFORMATTED", action = "read", status = "OLD")
read (unit = 10) x(:, :)
do i = 1, d
do j = 1, d
print *, x(i, j)
end do
end do
end program main
In the above program, the parameter d in the second line is the dimension of histogram.
It can be measured by e.g. "wc -l engref.01"