Matrix functions

Matrix functions are used to perform matrix calculations, like Matrix multiplication or Matrix inverse.

• Matrix multiplication (also: matr_mul)
• Matrix inverse (also: matr_inv)
• Matrix covariance (also: matr_var)

How these functions combine into regression models, with configurations that run as given for an ordinary least squares regression, a binomial logistic regression and a multinomial logit model: Linear and logistic regression.