matlib (version 0.9.8)

printMatEqn: 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)

Value

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

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)).

Author

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)