generate mean, variance and std using built in function

Hi

I am wondering how to generate mean, variance and std using built in function for the above numbers using built in function.

doing it with loops causing many bugs.

A=my array;

sum1=0;

for i=1:length(A)

sum1=sum1+A(i);

end

M=sum1/length(A);

sum2=0;

for i=1:length(A)

sum2=sum2+ (A(i)-M)^2;

end

V=sum2/length

Answer 1

[Torsten]

help mean

help var

help std

[Cris LaPierre]

Learn how to use these and other functions in Ch 7 of MATLAB Onramp.

Answer 2

[dpb]

stats=[[mean(A,2);var(A,2);std(A,2)];
       [mean(A,1);var(A,1);std(A,1)];]

will give you and array of the statistics by class followed by a row by year across classes -- whiich may or may not be of real interest.

I'd recommend converting to a table, though, and then you can use groupsummary (or grpstats if you have the Statistics TB) and have labels and everything automagically...