.flip_y {plotthis} | R Documentation |
Flip values on the y-axis direction, and negate the Y-Coordinates of SpatRaster, SpatVector Object and data.frame
Description
These internal functions flip the y-coordinates of SpatRaster
and SpatVector
objects from the terra
package.
For rasters, the function vertically flips the raster and adjusts its extent accordingly.
For vectors, the function negates the y-coordinates of all geometries.
For data frames, it negates the values in the specified y column.
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 |
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, a lot of elements have to be visualized with ggplot2::geom_sf()
, which won't work with
ggplot2::scale_y_reverse()
. See also this GitHub issue comment.
So we need these functions to flip the values along the y-axis and negate the y-coordinates.
This way, we can remove the negative sign from the y-axis labels to mimick the behavior of scale_y_reverse()
.#'
Value
For SpatRaster
input, a SpatRaster
object with flipped y-coordinates and adjusted extent.
For SpatVector
input, a SpatVector
object with y-coordinates negated.
For data.frame
input, a data frame with the specified y column negated.