Matlab error that I can't figure out please help!

I'm working with the code that I will show below and I keep on getting the error:

 "Subscript indices must either be real positive integers or logicals.

Error in opticalflow2D (line 62)

f5 = X1(( ndxm.*cos(1)+ndxn.*sin(1) ));"

if true
  X1 = [
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
1 1 1 1 1 1 1 1 1 1 1
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
];
if true
X2 = [
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0
1 1 1 1 1 1 1 1 1 1 1
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0
];

%imtool(X1)

%imtool(X2)

delta=1;

[fm,fn] = size(X1);

ndxm = 1+delta:fm-delta;

ndxn = 1+delta:fn-delta;

X1(ndxm)

f0 = X1(ndxm,ndxn);

fz = X2(ndxm,ndxn);

f1 = X1(ndxm,ndxn+delta);

f2 = X1(ndxm,ndxn-delta);

f3 = X1(ndxm+delta,ndxn);

f4 = X1(ndxm-delta,ndxn);

f5 = X1(( ndxm.*cos(1)+ndxn.*sin(1) ), ( ndxm.*sin(1)+ndxn.*cos(1) ));

f6 = X1(( ndxm.*cos(-1.)+ndxn.*sin(-1) ), ( ndxm.*sin(-1)+ndxn.*cos(-1) ));

end
end

Thank you!!

Answer 1

[Image Analyst]

Take the semicolons off these lines

ndxm = 1+delta:fm-delta
ndxn = 1+delta:fn-delta

so you'll see their values. Then go to this link.

[Brandon]

Thank you I figured it out with your help! I was going about it all wrong... figures!