Computes a weighted variance / standard deviation of a numeric vector or across rows or columns of a matrix.
weightedVar(x, w = NULL, idxs = NULL, na.rm = FALSE, center = NULL, ...)weightedSd(...)
rowWeightedVars(x, w = NULL, rows = NULL, cols = NULL, na.rm = FALSE, ...)
colWeightedVars(x, w = NULL, rows = NULL, cols = NULL, na.rm = FALSE, ...)
rowWeightedSds(x, w = NULL, rows = NULL, cols = NULL, na.rm = FALSE, ...)
colWeightedSds(x, w = NULL, rows = NULL, cols = NULL, na.rm = FALSE, ...)
a vector of weights the same length as x giving the weights
to use for each element of x. Negative weights are treated as zero
weights. Default value is equal weight to all values.
Not used.
Returns a numeric scalar.
This function handles missing values consistently with
weightedMean().
More precisely, if na.rm = FALSE, then any missing values in either
x or w will give result NA_real_.
If na.rm = TRUE, then all (x, w) data points for which
x is missing are skipped. Note that if both x and w
are missing for a data points, then it is also skipped (by the same rule).
However, if only w is missing, then the final results will always
be NA_real_ regardless of na.rm.
The estimator used here is the same as the one used by the "unbiased"
estimator of the Hmisc package. More specifically,
weightedVar(x, w = w) == Hmisc::wtd.var(x, weights = w),
For the non-weighted variance, see var.