neighbours: Return neighbouring pixels

In rcosmo: Cosmic Microwave Background Data Analysis

Description

Return the neighbouring pixels to a given pixel p that is specified at resolution j, in the nested order.

Usage

neighbours(p, j)

Arguments

p	Pixel index p at resolution j.
j	The resolution parameter with nside = 2^j.

Examples

## Return the neighbouring pixels for base pixel 1
neighbours(1, 0)

## Plot the neighbouring pixels for base pixel 1
demoNeighbours <- function(p,j) {
  neighbours(p, j)
  displayPixels(boundary.j = j, j = j, plot.j = j+3,
                spix = neighbours(p, j),
                boundary.col = "gray",
                boundary.lwd = 1,
                incl.labels = neighbours(p, j),
                col = "blue",
                size = 3)
  rcosmo::displayPixelBoundaries(nside = 1, col = "blue", lwd = 3)
}

demoNeighbours(1,2)
demoNeighbours(1,0)

rcosmo documentation built on Dec. 11, 2021, 9:29 a.m.