randomly select elements of an array

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

Answer 1

[Walter Roberson]

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))

[Noe alvarado]

thanks. i will try it

[Noe alvarado]

how i can select randomly "N" rows of a matrix?

for example

M =

[ a12, a12]

[ a21, a22]

[ a31, a32]

[ a41, a42]

For N=2

B =

[ a12, a12]

[ a31, a32]

[ a21, a22]

[Sourav Mondal]

>> A=[1 2 3; 4 5 6; 7 8 9]

A =

     1     2     3
     4     5     6
     7     8     9

>> N=2; >> B=A((1:N),:)

B =

     1     2     3
     4     5     6

[bkshn]

Hello Walter Roberson

If I want to find a random element in one row of a matrix, Could you help me How can I do?

For example I want to select a random element in last row of a matrix.

[Walter Roberson]

YourMatrix(end,randperm(size(YourMatrix,2), 1))

[feit feit]

Hi Walter Roberson,

I want to select a random element from a column, for example from Column 1 or Column 2 or Column 3. Would you help me with the code?

Thank you!

[Walter Roberson]

YourMatrix(randi(size(YourMatrix,1)), ColumnNumber)

[feit feit]

Thank you, Walter!

[Jaime Gurrola]

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'};

Answer 2

[Prasobhkumar P. P.]

histHandle= histfit(data,nBins,'normal');

[Val Ind] = max(histHandle(2).YData); %histHandle(2) corresponds to the curve fitted

M = histo18(2).XData(Ind);