Mean for the exponential distribution, returned as a numeric scalar or an array of
numeric scalars. m is the same size as mu.
Each element in m is the mean of the exponential distribution
specified by the corresponding element in mu.
The mean of the exponential distribution is mu.
Variance for the exponential distribution, returned as a numeric scalar or an array
of numeric scalars. v is the same size as mu.
Each element in v is the variance of the exponential distribution
specified by the corresponding element in mu.
The variance of the exponential distribution is mu
squared.