selectzerocols_byname: Select zero columns

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

Select zero columns

Description

Matrices with columns containing all zeroes are not invertible (singular). To diagnose this problem, it is useful to find the zero columns of a singular matrix. This function selects (extracts) only the zero columns of a matrix.

Usage

selectzerocols_byname(a, tol = 1e-06)

Arguments

a	A matrix or a list of matrices.
tol	The allowable deviation from 0 for any element.

Details

A column is said to be a zero column if all elements are within tol of zero.

Value

a with only zero columns selected.

Examples

m <- matrix(c(1, 0, 1,
              1, 0, 1),
            dimnames = list(c("r1", "r2"), c("c1", "c2", "c3")), 
            nrow = 2, ncol = 3, byrow = TRUE) %>% 
  setrowtype("rows") %>% setcoltype("cols")
selectzerocols_byname(m)

matsbyname documentation built on May 29, 2024, 8:10 a.m.