tableFromEpmGrid {epm}

Data table from epmGrid

Description

Given one or several epmGrid objects, sf objects, rasterLayers, SpatRasters, create a table of values and associated coordinate data.

Usage

tableFromEpmGrid(..., n = NULL, minTaxCount = 1, coords = NULL, id = FALSE)

Arguments

...

objects of class epmGrid, sf, sp, SpatRaster, RasterLayer or RasterStack. All should have the same projection.

n

number of cells to randomly subsample, no subsampling if NULL

minTaxCount

integer; cells with at least this many taxa will be included.

coords

if NULL, then points are sampled as needed, otherwise, data will be extracted at these specified coordinates.

id

boolean, should the grid cell index (of the first item in the inputs) be returned as well?

Details

A set of cells are identified in the input objects. If n=NULL, then all cells are used, otherwise cells are randomly subsampled. Values at those cells are then returned. This table construction can be particularly useful for subsequent statistical analyses.

Only cells with data in all inputs are returned. If n is greater than the number of cells with data, then fewer than n cells will be returned.

The first element provided should be a epmGrid object, and that will be the one used as a template for the sampled grid system.

If coords is provided, then data are extracted at those coordinates, and no subsetting of those points is done.

Value

data.frame with input variables, as well as "x" and "y".

Author(s)

Pascal Title

Examples

tamiasEPM
tamiasEPM <- addPhylo(tamiasEPM, tamiasTree)
tamiasEPM <- addTraits(tamiasEPM, tamiasTraits)
morphoDisp <- gridMetrics(tamiasEPM, metric='disparity')
meanPat <- gridMetrics(tamiasEPM, metric='meanPatristic')

tableFromEpmGrid(tamiasEPM, morphoDisp, meanPat, n = 100, 
minTaxCount = 2)

# this time request grid cell ID's, which would be useful
# for linking this table back to the grid system
tableFromEpmGrid(tamiasEPM, morphoDisp, meanPat, n = 100, 
minTaxCount = 2, id = TRUE)

# from predetermined set of coordinates
pts <- sf::st_sample(tamiasEPM[[1]], size = 10)
tableFromEpmGrid(tamiasEPM, morphoDisp, meanPat, n = 100, 
minTaxCount = 1, coords = pts)