# weighted_mean_sd: Helper function to compute weighted mean and standard deviation

## Description

Helper function to compute weighted mean and standard deviation.
Deals gracefully whether x is sparse matrix or not.

## Usage

weighted_mean_sd(x, weights = rep(1, nrow(x)))

## Value

A list with components.

meanvector of weighted means of columns of x

sdvector of weighted standard deviations of columns of x