Selecting a random value from vector but excluding particular values-CodePudding

I thought this was an easy one but I cannot find any solution for it.

I have this vector called cues= ["R" "B" "C" "P" "Y" "G"]; from which I want to randomly select one value, but excluding one (or two) of the values each time.

For example, I would like to get a random value from the vector excluding the "R" value, or in a second condition I would like "R" and "Y" not to be selected from the sample.

I have tried using randsample and randperm but neither of them seems to include this option.

CodePudding user response：

One intuitive way to achieve this would be taking your lists of all values and exclusions, and making a list of inclusions instead, then you can select from that list.

See the comments for each step:

cues= ["R" "B" "C" "P" "Y" "G"]; % All options
exclude = ["R" "Y"];             % Exclusions (could change in a loop or whatever)
include = setdiff( cues, exclude ); % Actual options without exclusions
selection = include( randi(numel(include)) ); % Random selection from options

CodePudding user response：

It seems I found a way to do it.

For a string vector, it can be done using erase function. For example:

cues_minusR = erase (cues,'R');

For a number vector (e.g., cues = [1 2 3 4 5 6]), it works this way:

c1Col=1;
c2Col=2;
cues(c1Col, : ) = [];
cues([c1Col, c2Col], : ) = [];