ipd.mat: Interpoint Distance Matrix

Description Usage Arguments Value Author(s) See Also Examples

View source: R/NNCTFunctions.r

Description

This function computes and returns the distance matrix computed by using the specified distance measure to compute the distances between the rows of the set of points x and y using the dist function in the stats package of the standard R distribution. If y is provided (default=NULL) it yields a matrix of distances between the rows of x and rows of y, otherwise, it provides a square matrix with i,j-th entry being the distance between row i and row j of x. This function is different from the dist function in the stats package. dist returns the distance matrix in a lower triangular form, and ipd.mat returns in a full matrix. ... are for further arguments, such as method and p, passed to the dist function.

Usage

1
ipd.mat(x, y = NULL, ...)

Arguments

x

A set of points in matrix or data frame form where points correspond to the rows.

y

A set of points in matrix or data frame form where points correspond to the rows (default=NULL).

...

Additional parameters to be passed on the dist function.

Value

A distance matrix whose i,j-th entry is the distance between row i of x and row j of y if y is provided, otherwise i,j-th entry is the distance between rows i and j of x.

Author(s)

Elvan Ceyhan

See Also

dist, ipd.mat.euc, dist.std.data

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#3D data points
n<-3
X<-matrix(runif(3*n),ncol=3)
mtd<-"euclidean" #try also "maximum", "manhattan", "canberra", "binary"
ipd.mat(X,method=mtd)
ipd.mat(X,method="minkowski",p=6)

n<-5
Y<-matrix(runif(3*n),ncol=3)
ipd.mat(X,Y,method=mtd)
ipd.mat(X[1,],Y,method=mtd)
ipd.mat(c(.1,.2,.3),Y,method=mtd)
ipd.mat(X[1,],Y[3,],method=mtd)

#1D data points
X<-as.matrix(runif(3)) # need to be entered as a matrix with one column 
#(i.e., a column vector), hence X<-runif(3) would not work
ipd.mat(X)

Y<-as.matrix(runif(5))
ipd.mat(X,Y)
ipd.mat(X[1,],Y)
ipd.mat(X[1,],Y[3,])

nnspat documentation built on May 10, 2021, 9:06 a.m.