how can i compute the stander diviation and confidence intervales for a matrix?

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RADWAN A F ZEYADI 2022-1-15

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评论： the cyclist 2022-1-18

i have matrix 51 rows and71 columns and i would like to compute and plot the result of std also i need to compute the confidence intervals 95%?

also after computing the std can i use imagesc command in order to see the range of std for the matrix ?

thank you

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the cyclist 2022-1-15

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If you have the Image Processing Toolbox, you can use the std2 function to compute the standard deviation of all the elements of a matrix. If not, you can use std from base MATLAB, but you need to make a vector out of the matrix first.

A = magic(5);
std2(A)
ans = 7.3598
std((A(:)))
ans = 7.3598

Sorry, but I didn't really understand your second question.

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RADWAN A F ZEYADI 2022-1-18

thank you but they are 2 vectors so can i compute for both of them sementanuesly?

the cyclist 2022-1-18

N = 1000;
X1 = randn(N,1);
X2 = randn(N,1) + 100;
X = [X1, X2];
x_lower = prctile(X, 2.5)
x_lower = 1×2
   -1.9542   97.9812
x_upper = prctile(X,97.5)
x_upper = 1×2
    1.9782  101.7530