CODEWITHSUNDEEP
matlabmatrix
brandbir
brandbir

Reputation: 315

Performing a function on each matrix value

I am currently experimenting with Matlab functions. Basically I am trying to perform a function on each value found in a matrix such as the following simple example:

k = [1:100];
p = [45 60 98 100; 46 65 98 20; 47 65 96 50];
p(find(p)) = getSum(k, find(p), find(p) + 1);

function x = getSum(k, f, g, h)
x = sum(k(f:g));
end

Why the corresponding output matrix values are all 3, in other words why all indices are depending on the first calculated sum?

The output is the following:

p =

     3     3     3     3
     3     3     3     3
     3     3     3     3

Upvotes: 0

Views: 79

Answers (1)

Luc Berthiaume
Luc Berthiaume

Reputation: 316

f:g returns the value between f(1,1) and g(1,1), so 1:2.

find(p) returns the indices of non zero values. Since all values are non-zero, you get all indices.

So if we break down the statement p(find(p)) = getSum(k, find(p), fin(p) + 1)

We get 

find(p) = 1:12

We then get f = 1:12 and g = 2:13 which lead to k = 1:2 (as explained above)

finally sum(1:2) = 3

And this value is apply over p(1:12), which is the same as p(:,:) (all the matrix)

Upvotes: 2

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