iszero_byname: Test whether this is the zero matrix

In matsbyname: An Implementation of Matrix Mathematics that Respects Row and Column Names

Test whether this is the zero matrix

Description

Note that this function tests whether the elements of abs(a) are ⁠<= tol⁠. The default value for tol is 1e-6. So, you can set tol = 0 to discover if a is EXACTLY the zero matrix.

Usage

iszero_byname(a, tol = 1e-06)

Arguments

a	A matrix or list of matrices.
tol	The allowable deviation from 0 for any element. Interpreted as an absolute value.

Value

TRUE Iff this is the zero matrix within tol.

Examples

zero <- matrix(0, nrow = 50, ncol = 50)
iszero_byname(zero)
nonzero <- matrix(1:4, nrow = 2)
iszero_byname(nonzero)
# Also works for lists
iszero_byname(list(zero, nonzero))
# And it works for data frames
DF <- data.frame(A = I(list()), B = I(list()))
DF[[1,"A"]] <- zero
DF[[2,"A"]] <- nonzero
DF[[1,"B"]] <- nonzero
DF[[2,"B"]] <- zero
iszero_byname(DF$A)
iszero_byname(DF$B)
iszero_byname(matrix(1e-10, nrow = 2))
iszero_byname(matrix(1e-10, nrow = 2), tol = 1e-11)

matsbyname documentation built on Oct. 19, 2023, 5:11 p.m.