# printMatEqn: Print Matrices or Matrix Operations Side by Side In matlib: Matrix Functions for Teaching and Learning Linear Algebra and Multivariate Statistics

## Description

This function is designed to print a collection of matrices, vectors, character strings and matrix expressions side by side. A typical use is to illustrate matrix equations in a compact and comprehensible way.

## Usage

 ```1 2``` ```printMatEqn(..., space = 1, tol = sqrt(.Machine\$double.eps), fractions = FALSE) ```

## Arguments

 `...` matrices and character operations to be passed and printed to the console. These can include named arguments, character string operation symbols (e.g., `"+"`) `space` amount of blank spaces to place around operations such as `"+"`, `"-"`, `"="`, etc `tol` tolerance for rounding `fractions` logical; if `TRUE`, try to express non-integers as rational numbers

## Value

NULL; A formatted sequence of matrices and matrix operations is printed to the console

## Author(s)

Phil Chalmers

`showEqn`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23``` ```A <- matrix(c(2, 1, -1, -3, -1, 2, -2, 1, 2), 3, 3, byrow=TRUE) x <- c(2, 3, -1) # provide implicit or explicit labels printMatEqn(AA = A, "*", xx = x, '=', b = A %*% x) printMatEqn(A, "*", x, '=', b = A %*% x) printMatEqn(A, "*", x, '=', A %*% x) # compare with showEqn b <- c(4, 2, 1) printMatEqn(A, x=paste0("x", 1:3),"=", b) showEqn(A, b) # decimal example A <- matrix(c(0.5, 1, 3, 0.75, 2.8, 4), nrow = 2) x <- c(0.5, 3.7, 2.3) y <- c(0.7, -1.2) b <- A %*% x - y printMatEqn(A, "*", x, "-", y, "=", b) printMatEqn(A, "*", x, "-", y, "=", b, fractions=TRUE) ```