sampling from a matrix
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Hello I am going to sample some columns in a matrix and return the columns that are not selected during the sampling. could you please help me?
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Accepted Answer
José-Luis
on 20 Dec 2013
bla = rand(10);
%Columns you sample:
my_cols = [1 5 7];
%Extract them:
sample = bla(:,my_cols);
nCols = 1:size(bla,2);
no_sample = nCols(~ismember(nCols,my_cols));
no_sample =bla(:,no_sample);
More Answers (1)
dpb
on 20 Dec 2013
Edited: dpb
on 20 Dec 2013
Sample how? If use randperm, say, as
icol=randperm(size(x,2),N);
to select N random columns from the array x to get the "nonsampled" columns you could instead simply use
inot=randperm(size(x,2),size(x,2)-N);
which is simply picking a random set of the obverse size to not sample--same thing in the end.
Or, if you are using the sampled column values first and then wanting the ones that weren't used both then first select as in the former and the other columns are simply
inot=setdiff([1:size(x,2)],icol);
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