dropRows: Remove rows in a data.table, data.frame, or matrix.

In adamlilith/fasterRaster: Faster Raster and Spatial Vector Processing Using 'GRASS GIS'

Remove rows in a data.table, data.frame, or matrix.

Description

As of September of 2023, the data.table package does not have a function for removing rows by index. This function does this job.

Usage

## S4 method for signature 'data.table'
dropRows(x, drops)

## S4 method for signature 'data.frame'
dropRows(x, drops)

## S4 method for signature 'matrix'
dropRows(x, drops)

Arguments

x	A data.table or data.frame.
drops	Numeric, integer, or logical vector: Indices or indicators of rows to remove. If a logical vector is supplied, rows that correspond to TRUE will be removed. If the vector is shorter than the number of rows, values of drops will be recycled.

Value

A data.table or data.frame.

Examples

library(data.table)

dt <- data.table(
   x = 1:10,
   y = letters[1:10],
   z = rnorm(10)
)

# make some values NA
dt[x == 4 | x == 8, y := NA_character_]
dt

# Replace NAs:
replaceNAs(dt, replace = -99, cols = "y")
dt

# Drop rows:
dropped <- dropRows(dt, 8:10)
dropped

# NB May not print... in that case, use:
print(dropped)

# We can also use replaceNAs() on vectors:
y <- 1:10
y[c(2, 10)] <- NA
replaceNAs(y, -99)

# Same as:
y <- 1:10
y[c(2, 10)] <- NA
y[is.na(y)] <- -99

adamlilith/fasterRaster documentation built on Dec. 21, 2024, 2:04 a.m.