read_columns-methods: Read a set of column vector from an input source (e.g....

In bbuchsbaum/neuroim2: Data Structures for Brain Imaging Data

Read a set of column vector from an input source (e.g. ColumnReader)

Description

Read a set of column vector from an input source (e.g. ColumnReader)

Usage

read_columns(x, column_indices)

## S4 method for signature 'ColumnReader,integer'
read_columns(x, column_indices)

Arguments

x	the input channel
column_indices	the column indices

Value

A numeric matrix consisting of the requested column vectors.

Examples

# Create a reader function that returns random data
reader_func <- function(cols) {
  matrix(rnorm(100 * length(cols)), 100, length(cols))
}

# Create a ColumnReader with 100 rows and 10 columns
col_reader <- ColumnReader(nrow = 100L, ncol = 10L, reader = reader_func)

# Read columns 1, 3, and 5
cols <- read_columns(col_reader, c(1L, 3L, 5L))
dim(cols) == c(100, 3)

bbuchsbaum/neuroim2 documentation built on Feb. 26, 2025, 3:49 p.m.