how to replace multiple values per second with their standard deviaton?

Question

Viktor G. 2020-8-4

0
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https://ww2.mathworks.cn/matlabcentral/answers/575161-how-to-replace-multiple-values-per-second-with-their-standard-deviaton

回答： Viktor G. 2020-8-4

I know about the function that gives you the mean value of the multiple data points however in this case I need their standard deviaton, so this function wont do it.

TT2 = retime(TT,'hourly','mean')

I am guessing i have to use a for loop, but i am just wondering if there is a more efficent way to do it other than comparing all of the values. I have a table that has 200 values per second and in the end i just need to have 1 value per second that is equal to the standard deviation of those 200. I am using this for loop

for i=i:200:L-r
   Y1(k,:)=std(Z(i:(i+200-1),:)); 
   k=k+1;
end

However I am not always sure that there are exactly 200 values per second (for example there might be 199 or 201 sometimes), and that is where the function mentioned first would've been helpfull. I would appreciate any help.

           Var1             Var2       Var3  
    ___________________    _______    _______
    01/02/2014 00:07:24    -3.5469    -102.63
    01/02/2014 00:07:24    -5.0115    -102.78
    01/02/2014 00:07:24    -6.7526    -103.03