printMatEqn: Print Matrices or Matrix Operations Side by Side

In matlib: Matrix Functions for Teaching and Learning Linear Algebra and Multivariate Statistics

Print Matrices or Matrix Operations Side by Side

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

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, using the fractions function; if you require greater accuracy, you can set the cycles (default 10) and/or max.denominator (default 2000) arguments to fractions as a global option, e.g., options(fractions=list(cycles=100, max.denominator=10^4)).

Value

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

Author(s)

Phil Chalmers

See Also

showEqn

Examples

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)

matlib documentation built on Oct. 3, 2024, 1:09 a.m.