Calculate 2 standard deviations
조회 수: 99(최근 30일)
I am trying to calculate +/- two standard deviations from the mean of a bunch of values. I am not sure if I am using the standard deviation function properly. Would I just multiply by two to get 2 standard deviations?
dmean = mean(values(:,1)); upperstd = dmean+2*std(values(:,1)); lowerstd = dmean-2*std(values(:,1));
Wayne King 2011년 8월 28일
Hi Chris, for a matrix of data
x = randn(10,4);
gives the sample means of the columns plus/minus 2 times the standard deviation. The question is whether you really want the sample standard deviation here, or the standard error of the mean.