How to compare the values ​​of three matrices are equal?

Hi

I need help with comparison matrices. I'm new to MatLab. Please help me.

I have three matrices R, S and T (size 95956x1) and I need to compare all elements them and see which elements are equal, then the same values we multiply by a fourth matrix.

In a Matlab file I read the coordinates and separate them into three matrices, thus obtaining matrices R, S and T saved in "data.mat". Then I read in another file "data.mat" and opened a For loop

   for t=1:1:length(CoordinateIndex)

               
        index = R == S ;

      ts=ts+1;
  end

Now I do not know if this is correct and how I will multiply to only those values which are equal to a fourth matrix. Please could you help me? I am very grateful

Jadiel

[Azzi Abdelmalek]

can you explain: then the same values we multiply by a fourth matrix. And you did not precise what are you going to multiply by the fourth matrix

[per isakson]

See: Using Logicals in Array Indexing

Answer 1

[per isakson]

The link once more: Using Logicals in Array Indexing

I don't exactly understand what you want to do. However, here is an extra example to the documentation on locigal indexing.

Create some data. It's short column vectors to make them easy to inspect.

    N = 12;
    R = randi( [1,3], [N,1] );
    S = randi( [1,3], [N,1] );
    T = randi( [1,3], [N,1] ); 
    f = randi( [1,3], [N,1] );

Create a logical index, which is true when R(i)==S(i), else is false

    is_RS = (R==S);

Multiply T(i) by f(i) where R(i)==S(i)

    T(is_RS) = f(is_RS) .*  T(is_RS);

[Image Analyst]

Exactly how I'd do it. Works for integers only. For floating point values, see the FAQ: http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F for solution.