Replacing Values in Matrix with NaN's based on Row and Column

Hi everyone!

I hope all of you are well. I'm currently working on replacing specific element values with NaN's within a matrix that is 300x600. I want to replace the values based on pairs of rows and columns that I have previously identified. I'm unsure if I would use a for loop or if I would have to create a mask or if there is a simpler way of approaching the problem, but any help would be greatly appreciated! Thank you in advance! :)

M.

Answer 1

[madhan ravi]

matrix(ismember(matrix, [3,7,1])) = nan % an example of replacing numbers 3,7 & 9 with nans

% or
matrix = rand(5); % an example 
rows = [2, 5]; 
columns = [1, 4];
idx = rows + (columns - 1) * size(matrix, 1);
matrix(idx) = nan

Answer 2

[Tommy]

Possibly, you could use sub2ind() to convert your rows and columns to linear indices:

ind = sub2ind(size(yourMatrix), yourRows, yourCols);
yourMatrix(ind) = NaN;

[Michelle De Luna]

Tommy, thank you for your speedy response! I've accepted the second response but appreciate your help.