randomly select elements of an array
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Noe alvarado
am 12 Apr. 2012
Kommentiert: Steven Lord
am 7 Feb. 2022
Hi How i can select randomly elements from a matrix o array
I have the matrix and i want to select "x" numbers of elements
thanks
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Walter Roberson
am 12 Apr. 2012
msize = numel(YourMatrix);
idx = randperm(msize);
YourMatrix(idx(1:x))
If you have a fairly new version of MATLAB, you can instead use
msize = numel(YourMatrix);
YourMatrix(randperm(msize, x))
10 Kommentare
Jaime Gurrola
am 7 Dez. 2020
Hi walter, i want to select a random element from this array, help please
A={'Yellow','Green','Blue','Orange','Black','Grey','Red','Brown','Purple','White'};
Weitere Antworten (2)
Prasobhkumar P. P.
am 28 Jul. 2020
Bearbeitet: Walter Roberson
am 3 Sep. 2021
histHandle= histfit(data,nBins,'normal');
[Val Ind] = max(histHandle(2).YData); %histHandle(2) corresponds to the curve fitted
M = histo18(2).XData(Ind);
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Adam Wyatt
am 3 Sep. 2021
Bearbeitet: Adam Wyatt
am 3 Sep. 2021
Use "randsample"
For array:
Arry = [1 4 5 7 8 9];
Smpl = randsample(Arry, 3)
For strings:
Arry = ["Yellow" "Green" "Blue" "Orange" "Black" "Grey" "Red" "Brown" "Purple" "White"];
Smpl = randsample(Arry, 2)
How do you want to sample the matrix? If its any element, just convert to array (e.g. Mat(:)). Otherwise you have to apply the function to each row/column separately.
3 Kommentare
Piyush Kant
am 7 Feb. 2022
Is there any method/parameter with which we can reproduce same random series so that the different algorithms can be evaluated? I know that way it wont be a random series anymore still the psudorandomness can be helpful for multiple runs.
Steven Lord
am 7 Feb. 2022
Some older functions that use random numbers internally (like eigs, which generates a starting point at random if one is not given to it) have the ability to specify inputs that avoid the randomness (in the case of eigs by specifying v0 in the options structure or specifying the StartVector name-value pair argument.)
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