GWmodel (version 2.4-1)

gw.dist: Distance matrix calculation

Description

Calculate a distance vector(matrix) between any GW model calibration point(s) and the data points.

Usage

gw.dist(dp.locat, rp.locat, focus=0, p=2, theta=0, longlat=F)

Value

Returns a numeric distance matrix or vector; matrix with its rows corresponding to the observations and its columns corresponds to the GW model calibration points.

Arguments

dp.locat

a numeric matrix of two columns giving the coordinates of the data points

rp.locat

a numeric matrix of two columns giving the coordinates of the GW model calibration points

focus

an integer, indexing to the current GW model point, if focus=0, all the distances between all the GW model calibration points and data points will be calculated and a distance matrix will be returned; if 0<focus<length(rp.locat), then the distances between the 'focus'th GW model points and data points will be calculated and a distance vector will be returned

p

the power of the Minkowski distance, default is 2, i.e. the Euclidean distance

theta

an angle in radians to rotate the coordinate system, default is 0

longlat

if TRUE, great circle distances will be calculated

Author

Binbin Lu

See Also

dist in stats

Examples

dp<-cbind(sample(100),sample(100))
rp<-cbind(sample(10),sample(10))
#Euclidean distance metric is used.
dist.v1<-gw.dist(dp.locat=dp, focus=5, p=2, theta=0, longlat=FALSE)
#Manhattan distance metric is used.
#The coordinate system is rotated by an angle 0.5 in radian.
dist.v2<-gw.dist(dp.locat=dp, focus=5, p=1, theta=0.5)
#Great Circle distance metric is used.
dist.v3<-gw.dist(dp.locat=dp, focus=5, longlat=TRUE)
#A generalized Minkowski distance metric is used with p= 0.75 .
#The coordinate system is rotated by an angle 0.8 in radian.
dist.v4<-gw.dist(dp.locat=dp,rp.locat=rp, focus=5, p=0.75,theta=0.8)
################################
#matrix is calculated
#Euclidean distance metric is used.
dist.m1<-gw.dist(dp.locat=dp, p=2, theta=0, longlat=FALSE)
#Manhattan distance metric is used.
#The coordinate system is rotated by an angle 0.5 in radian.
dist.m2<-gw.dist(dp.locat=dp, p=1, theta=0.5)
#Great Circle distance metric is used.
#dist.m3<-gw.dist(dp.locat=dp, longlat=TRUE)
#A generalized Minkowski distance metric is used with p= 0.75 .
#The coordinate system is rotated by an angle 0.8 in radian.
dist.m4<-gw.dist(dp.locat=dp,rp.locat=rp, p=0.75,theta=0.8)