format type in determinant

clc;
close all;
clear all;
A = [1 2 5 ; 4 4 6 ; 7 8 9];
[x1 x2]=gradient(A);
disp(x1);
disp('GRADIENT IN HORIZONTAL DIRECTION');
disp(x2);
disp('GRADIENT IN VERTICAL DIRECTION');
x=x1+x2;
disp(x);

C=cov(x);
disp(C);
l=det(C);
disp(l);
title('determinant');
S=sqrt(l);
disp(S);
title('square root');
U=2*pi*(2.1*2.1);
F=S/U;

determinant value calculated manually and by pgm varies..format type problem is specified already..how i can solve this?or can i use this code as it is

[Oleg Komarov]

Solve what?

[Walter Roberson]

Looks like a duplicate question to me.

http://www.mathworks.com/matlabcentral/answers/14483-finding-determinant-of-matrix-after-taking-covariance

[Walter Roberson]

Looks like a duplicate question to me.

http://www.mathworks.com/matlabcentral/answers/14483-finding-determinant-of-matrix-after-taking-covariance