function standard deviation matlab
MATLAB's std function will return the standard deviation of a distribution, so we just have to divide this by the square root of the sample size to get the standard error of the mean (SEM). The standard deviation describes the spread of a sample distribution. The SEM describes certainty with which we know the mean of the underlying population based upon our sample of it. More specifically, the SEM is the theoretical standard deviation of the sample-mean's estimate of a population mean. To make the SEM more informative we can convert it to a confidence interval.