standard deviation of a vector or a ts
sd=st_dev(x,cr)
* x = a time series or a matrix
* cr = (only if x is a matrix and even in thta case optional)
. 'r' or 1 for rowwise standard deviation
. 'c' or 2 for columnwise standard deviation
* s = the vector of the time series values
load(GROCERDIR+'/data/bdhenderic.dat') // load Hendry and Ericsson database y=st_dev(lm1) | ![]() | ![]() |