... interpolate to a new projection?

using SpeciesDistributionToolkit
using CairoMakie

The interpolate method can be used to project data into another coordinate system. For example, we can get temperature data about metropolitan France and Corsica, in ESPG:4326:

spatial_extent = (; left = -4.87, right = 9.63, bottom = 41.31, top = 51.14)
dataprovider = RasterData(CHELSA1, BioClim)
layer = SDMLayer(dataprovider; layer = 1, spatial_extent...)

SDM Layer with 1497697 Int16 cells
	Proj string: +proj=longlat +datum=WGS84 +no_defs
	Grid size: (1180, 1741)

And project them to the more locally appropriate EPSG:27574:

proj_string = "+proj=lcc +lat_1=42.165 +lat_0=42.165 +lon_0=0 +k_0=0.99994471 +x_0=234.358 +y_0=4185861.369 +ellps=clrk80ign +pm=paris +towgs84=-168,-60,320,0,0,0,0 +units=m +no_defs"
ws = interpolate(layer; dest = proj_string)

SDM Layer with 1346822 Float32 cells
	Proj string: +proj=lcc +lat_1=42.165 +lat_0=42.165 +lon_0=0 +k_0=0.99994471 +x_0=234.358 +y_0=4185861.369 +ellps=clrk80ign +pm=paris +towgs84=-168,-60,320,0,0,0,0 +units=m +no_defs
	Grid size: (1180, 1741)

By default, this produces a layer with the same dimension as the input, and uses bilinear interpolation:

Code for the figure

fig, ax, hm = heatmap(
    ws;
    colormap = :navia,
    figure = (; size = (800, 400)),
    axis = (; aspect = DataAspect()),
)
Colorbar(fig[:, end + 1], hm)

Overwrite a layer

There is an interpolate! method that will perform interpolation on an already existing layer. This is useful if you want to rapidly bring data from a layer to something compatible with another layer.