grid: Create a grid GVector

In adamlilith/fasterRaster: Faster Raster and Spatial Vector Processing Using 'GRASS GIS'

Create a grid GVector

Description

This function creates a GVector of "wall-to-wall" cells (like a lattice). The input can be a GVector or GRaster, which provides the extent of the output.

Usage

## S4 method for signature 'GRaster'
grid(x, nx = NULL, ny = NULL, use = "number", angle = 0)

## S4 method for signature 'GVector'
grid(x, nx = NULL, ny = NULL, use = "number", angle = 0)

Arguments

x	A GRaster or GVector.
nx, ny	Integer or numeric: If use is "number", then these values represent the number of rows and columns in the grid. If use is size, then these values represent the size of the cells in the x- and y-dimensions.
use	Character: How to generate the grid. If this is number (default), then nx and ny are taken to be the number of grid cells. If size, then nx and ny are taken to be the size of the grid cells.
angle	Numeric: Degrees by which to rotate grid (from north, clockwise).

Value

A GVector.

See Also

hexagons(), module v.mkgrid in GRASS

Examples

if (grassStarted()) {

# Setup
library(sf)

# Points vector of specimens of species in the plant genus Dypsis
madCoast0 <- fastData("madCoast0")

# Convert sf to a GVector:
coast <- fast(madCoast0)

### grid

# grid specified by number of cells in x-dimension
g1 <- grid(coast, nx = 10)
plot(coast, col = "cornflowerblue")
plot(g1, add = TRUE)

# grid specified by number of cells in x- and y-dimension
g2 <- grid(coast, nx = 10, ny = 5)
plot(coast, col = "cornflowerblue")
plot(g2, add = TRUE)

# grid specified by size of cells in both dimensions
g3 <- grid(coast, nx = 1250, ny = 2000, use = "size")
plot(coast, col = "cornflowerblue")
plot(g3, add = TRUE)

### hexagons

hexes <- hexagons(coast, ny = 10)
plot(hexes)
plot(coast, lwd = 2, add = TRUE)

hexes <- hexagons(coast, ny = 10, expand = c(0.3, 0.1))
plot(hexes)
plot(coast, lwd = 2, add = TRUE)

}

adamlilith/fasterRaster documentation built on Dec. 21, 2024, 2:04 a.m.