Trouble allocating values to matrix

Hello.

I am trying to assign values to a matrix, but am having some trouble doing so.

    clc; 
  clear all; 
  X=ones(22,22); 
  X1=3.2;
  X2=1.5; 
  T1=X(1:3,1:3);
  T2=X(10:13,9:11);
  T3=X(20:22,20:21);

if T1
X*X1
else if T2
X.*X1
else if T3
X.*X1
else  
X.*X2
end
end
end
end

When I do this, every value in the matrix becomes 3.2 (X1). I am not using the else statement correctly I believe.

The goal is to have the X1 values at the locations specified by T1,T2 and T3 and have everything else equal to X2.

All help greatly appreciated.

bt

Answer 1

[Walter Roberson]

if T1

is equivalent to

if all(T1(:))

That is, the condition is true only if every value in the matrix is non-zero.

Answer 2

[the cyclist]

In addition to Walter's answer, note that in your if ... else statements, you never actually assign values to any variables. You only display X.*X1, etc.