variance(x, ...)
# S3 method for class 'numeric'
variance(x, ...)
# S3 method for class 'matrix'
variance(x, ...)
# S3 method for class 'numeric'
covariance(x, ...)The implementation of variance() for numeric variables coerces the input to
a vector then uses stats::var() to compute the variance. This means that,
unlike stats::var(), if variance() is passed a matrix or a 2-dimensional
array, it will still return the variance (stats::var() returns the
covariance matrix in that case).