Center and/or Scale Row-subsets of a Matrix or Matrix-like Object

This function centers and/or scales the row-subsets of a numeric matrix or matrix-like object.

Implementation of split_scale for matrix objects. See split_scale for the generic definition and complete documentation.

Implementation of split_scale for DenseNeuroVec objects. See split_scale for the generic definition and complete documentation.

Usage

split_scale(x, f, center, scale)

# S4 method for class 'matrix,factor,logical,logical'
split_scale(x, f, center = TRUE, scale = TRUE)

# S4 method for class 'matrix,factor,missing,missing'
split_scale(x, f)

# S4 method for class 'DenseNeuroVec,factor,missing,missing'
split_scale(x, f)

# S4 method for class 'DenseNeuroVec,factor,logical,missing'
split_scale(x, f, center)

# S4 method for class 'DenseNeuroVec,factor,logical,logical'
split_scale(x, f, center, scale)

Arguments

x: A DenseNeuroVec object
f: Factor for grouping
center: Logical indicating whether to center
scale: Logical indicating whether to scale

Value

A new matrix or matrix-like object in which the original rows have been grouped by 'f' and then centered and/or scaled for each grouping.

Matrix of scaled values

Scaled DenseNeuroVec object

Examples


M <- matrix(rnorm(1000), 10, 100)
fac <- factor(rep(1:2, each=5))
Ms <- split_scale(M, fac)

## Correctly centered
all(abs(apply(Ms[fac == 1,], 2, mean)) < .000001)
#> [1] TRUE
all(abs(apply(Ms[fac == 2,], 2, mean)) < .000001)
#> [1] TRUE

## Correctly scaled
all.equal(apply(Ms[fac == 1,], 2, sd), rep(1, ncol(Ms)))
#> [1] TRUE
all.equal(apply(Ms[fac == 2,], 2, sd), rep(1, ncol(Ms)))
#> [1] TRUE

Center and/or Scale Row-subsets of a Matrix or Matrix-like Object

Usage

Arguments

Value

See also

Examples