dot_flip_y: Flip y-coordinates for spatial data objects

In plotthis: High-Level Plotting Built Upon 'ggplot2' and Other Plotting Packages

Flip y-coordinates for spatial data objects

Description

These internal S3 methods flip the y-coordinates of SpatRaster, SpatVector, and data.frame objects.

For rasters, the raster is flipped vertically and its extent is negated. For vectors, the y-coordinates of all geometries are negated. For data frames, the specified y column is negated.

Usage

.flip_y(data, ...)

## S3 method for class 'SpatRaster'
.flip_y(data, ...)

## S3 method for class 'SpatVector'
.flip_y(data, ...)

## S3 method for class 'data.frame'
.flip_y(data, y = "y", ...)

Arguments

data	A SpatRaster, SpatVector, or data.frame.
...	Additional arguments (not used).
y	A character string specifying the y column name for data.frame input. Ignored for SpatRaster and SpatVector. Default is "y".

Details

These functions are intended for internal use to facilitate coordinate transformations. When visualizing spatial data, it is often necessary to flip the y-axis to put the origin at the top-left corner. However, geom_sf() does not work with scale_y_reverse(). See this GitHub comment for details. These functions negate the y-coordinates so that the axis labels can be displayed with reversed sign, mimicking scale_y_reverse().

Value

For SpatRaster input, a SpatRaster flipped vertically with negated y-extent. For SpatVector input, a SpatVector with negated y-coordinates. For data.frame input, a data frame with the specified y column negated.

plotthis documentation built on July 9, 2026, 5:07 p.m.