SpatioTemporal (version 1.1.2)

crossDist: Computed the Euclidian Distance Matrix

Description

Computed the Euclidian distance matrix between to sets of points.

Usage

crossDist(coord1, coord2 = coord1)

Arguments

coord1,coord2

Matrices with the coordinates of locations, between which distances are to be computed.

Value

• A dim(coord1)[1]-by-dim(coord2)[1] distance matrix.

See Also

Other basic linear algebra: blockMult, dotProd, invCholBlock, makeCholBlock, norm2, solveTriBlock, sumLogDiag

Other covariance functions: evalCovFuns, makeSigmaB, makeSigmaNu, namesCovFuns, parsCovFuns, updateCovf

Examples

##First create some random locations
x <- rnorm(5)
y <- rnorm(5)

##compute distance matrix
D <- crossDist( cbind(x,y) )

##or distance between different locations
X <- matrix(rnorm(6),3,2)
Y <- rbind(X, matrix(rnorm(8),4,2))
Dcross <- crossDist(X, Y)

##or distances between coordinates in R3
C1 <- matrix(rnorm(9),3,3)
C2 <- matrix(rnorm(12),4,3)
Dcross.R3 <- crossDist(C1, C2)


D.alt <- as.matrix(dist(cbind(x,y)))
  if( max(abs(D-D.alt)) > 1e-13 ){
    stop("In 'crossDist', distance matrix not equal")
  }
  if( max(abs(Dcross-as.matrix(dist(Y))[1:3,])) > 1e-13 ){
    stop("In 'crossDist', cross-distance matrix not equal")
  }
  D.alt <- sqrt(rowSums( (matrix(C1[1,], dim(C2)[1], dim(C2)[2], byrow=TRUE) -
                          C2)^2 ))
  if( max(abs(D.alt-Dcross.R3[1,])) > 1e-13 ){
    stop("In 'crossDist', cross-distance, R3, matrix not equal")
  }