To select the indices of logical "1" in first 2D matrix, and then replace those corresponding indices in second 2D matrix with logical "0"

Dear Researchers and Programmers,

I have 2D matirx with logical 1, and 0. I need to select the indices having logical value 1.

Then in the second matrix, I want to replace those indices with zero.

I have attached both the matrices one is binary image and other is processed image.

I look forward to receive your valueable suggestions.

Many thanks.

Answer 1

[Cris LaPierre]

Use logical indexing (Ch 11 of MATLAB Onramp)

A = randi([0 3],5)

A = 5×5

1 0 1 1 2 0 3 1 2 3 3 3 1 2 2 0 1 0 2 0 2 1 0 0 3

B = rand(5);

B(A==1) = 0

B = 5×5

0 0.5810 0 0 0.1176 0.7124 0.2019 0 0.8901 0.0881 0.5986 0.7831 0 0.6246 0.6896 0.2216 0 0.0883 0.1362 0.5453 0.9653 0 0.8447 0.6397 0.7059

[Amjad Iqbal]

@Cris LaPierre

Thank you so much dear @Cris LaPierre for your promot answer.

this operation again output in logical image,

In the second matrxi I need to replace only those indices with zero (which I select in the 1st matrix) rest of the matrix must contains same values as before, varying from [0 700]

[Cris LaPierre]

If you are getting a logical output, you have not done what I showed. In my example, B is an array of doubles, not logicals. You use a logical array to perform the indexing (A==1). The assumption is that A and B are the same size.

[Amjad Iqbal]

@Cris LaPierre

Yes you are right, It works now. Fantastic.

Many thanks once again.