Skip to contents

Shift and rotate a raster or a vector

Source: R/shift_and_rotate.R
shift_and_rotate.Rd

shift_and_rotate() shifts a raster or vector by a specified horizontal distance rotating the data around the dateline.

This function is particularly useful for working with rasters and vectors that span the dateline (e.g., the Russian territory).

Usage

shift_and_rotate(x, dx = -45, precision = 5, overlap_tol = 0.1)

Arguments

x

A SpatRaster or SpatVector object to be shifted and rotated.

dx

(optional) A numeric value indicating the amount of the horizontal shift in degrees. Positive values shift to the right, negative values shift to the left (default: -45).

precision

(optional) A numeric value specifying the number of decimal digits to use when rounding longitude and latitude coordinates (default: 5).

overlap_tol

(optional) A numeric value specifying the tolerance for overlapping geometries when combining vectors. This value controls the allowable error when merging overlapping geometries (default: 0.1).

Value

A object of the same class as x that has been shifted and rotated by the specified amount in degrees.

See also

Other raster functions: shift_and_crop()

Examples

library(dplyr)
library(geodata)
library(terra)

## Raster example

if (curl::has_internet()) {
  raster <-
    expand.grid(
      seq(-179.75, 179.75, by = 0.5),
      seq(-89.75, 89.75, by = 0.5)
    ) |>
    as_tibble() |>
    rename(x = Var1, y = Var2) |>
    mutate(value = rnorm(259200)) |>
    rast(type = "xyz") %>%
    `crs<-`("epsg:4326")

  world_shape <- world(path = tempdir())
  raster <- raster |> crop(world_shape, mask = TRUE)

  raster |> plot()

  raster |> shift_and_rotate(-45) |> plot()

  raster |> shift_and_rotate(-90) |> plot()

  raster |> shift_and_rotate(-135) |> plot()

  raster |> shift_and_rotate(-180) |> plot()

  raster |> plot()

  raster |> shift_and_rotate(45) |> plot()

  raster |> shift_and_rotate(90) |> plot()

  raster |> shift_and_rotate(135) |> plot()

  raster |> shift_and_rotate(180) |> plot()
}











## Vector example

if (curl::has_internet()) {
  vector <- gadm(country = "rus", level = 0, path = tempdir())

  vector |> plot()

  vector |> shift_and_rotate(-45) |> plot()

  vector |> shift_and_rotate(45) |> plot()
}