matrixSmooth: Smooth a Matrix

In oce: Analysis of Oceanographic Data

Smooth a Matrix

Description

The values on the edge of the matrix are unaltered. For interior points, the result is defined in terms in terms of the original as follows. r_{i,j} = (2 m_{i,j} + m_{i-1,j} + m_{i+1,j} + m_{i,j-1} + m_{i,j+1})/6. Note that missing values propagate to neighbours.

Usage

matrixSmooth(m, passes = 1)

Arguments

m	a matrix to be smoothed.
passes	an integer specifying the number of times the smoothing is to be applied.

Value

A smoothed matrix.

Author(s)

Dan Kelley

Examples

library(oce)
opar <- par(no.readonly = TRUE)
m <- matrix(rep(seq(0, 1, length.out=5), 5), nrow=5, byrow=TRUE)
m[3, 3] <- 2
m1 <- matrixSmooth(m)
m2 <- matrixSmooth(m1)
m3 <- matrixSmooth(m2)
par(mfrow=c(2, 2))
image(m,  col=rainbow(100), zlim=c(0, 4), main="original image")
image(m1, col=rainbow(100), zlim=c(0, 4), main="smoothed 1 time")
image(m2, col=rainbow(100), zlim=c(0, 4), main="smoothed 2 times")
image(m3, col=rainbow(100), zlim=c(0, 4), main="smoothed 3 times")
par(opar)

oce documentation built on July 9, 2023, 5:18 p.m.