sets and gets default mode for handling NaNs
FLAG = flag_impl_skip_nan() flag_impl_skip_nan(FLAG) prevFLAG = flag_impl_skip_nan(nextFLAG)
gets current mode
skips NaN's (the default mode if no mode is set)
NaNs are propagated; input NaN's give NaN's at the output
prevFLAG = flag_impl_skip_nan(nextFLAG) gets previous set FLAG and sets FLAG for the future
flag_impl_skip_nan(prevFLAG) resets FLAG to previous mode
It is used in: sumskipnan, median, quantiles, trimean and affects many other functions like: center, kurtosis, mad, mean, moment, rms, sem, skewness, statistic, std, var, zscore etc.
The mode is stored in the global variable FLAG_impl_skip_nan It is recommended to use flag_impl_skip_nan(1) as default and flag_impl_skip_nan(0) should be used for exceptional cases only. This feature might disappear without further notice, so you should really not rely on it.