Select elements from only three consecutive columns.
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Hello all,
I have a 12 by 12 matrix, and I want to select 10 random elements. The elements should be from only three consecutive columns.
For example, I want to use 10 random elements from columns (1, 2, 3) or they could be from columns (2, 3, 4) or columns(3, 4, 5) and so on.
Any help please.
Thank you
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Guillaume
2019-4-5
编辑:Guillaume
2019-4-5
startcolumn = randi(size(yourmatrix, 2) - 2); %select 1st of 3 consecutive column at random
candidateelements = yourmatrix(:, startcolumn : startcolumn + 2); %elements from the 3 consecutive columns
selectedelements = candidateelements(randperm(numel(candidateelements), 10)); %take 10 of these at random
2 个评论
Guillaume
2019-4-5
For that, it would have been better to start a new question as this is a completely different scenario.
[ux, ~, rows] = unique(yourmatrix(:, 2)); %get unique values and matching rows
startx = randi(numel(ux) - 2); %start index of 3 consecutive x
rowpool = find(ismember(rows, startx:startx + 2)); %row index of all rows within selected 3 consecutive x
selectedrows = rowpool(ranpderm(numel(rowpool, 10))); %take 10 rows at random out of the pool
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