filter_low_var: Remove low-variance (near-constant) variables

In dataprep: Fast, Efficient, and Versatile Data Preprocessing and Reshaping with 'C++', 'OpenMP' & 'SIMD'

Remove low-variance (near-constant) variables

Description

Removes numeric columns whose variance (or standard deviation) falls below a specified threshold.

Usage

filter_low_var(data, cols = NULL, cutoff = 0.01,
               method = "var", verbose = FALSE)

Arguments

data	A data frame.
cols	Column indices or names of numeric variables to check. If NULL, all numeric columns are used.
cutoff	Variance (or standard deviation) threshold. Columns with statistic <= cutoff are removed.
method	Statistic to use: "var" for variance, "sd" for standard deviation.
verbose	Logical; if TRUE, prints removed column names and their variance.

Details

Variance is computed with NA values removed. For method = "sd", the standard deviation is compared directly against cutoff; no internal squaring is performed.

Value

A data frame with low-variance columns removed.

Examples

data <- data.frame(
  id = 1:100,
  const = rep(5, 100),
  noise = rnorm(100, sd = 0.005)
)
filter_low_var(data, cutoff = 0.001)

dataprep documentation built on Oct. 1, 2026, 5:07 p.m.