| ipd.mat {nnspat} | R Documentation |
Interpoint Distance Matrix
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
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= |
... |
Additional parameters to be passed on the |
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,
and dist.std.data
Examples
#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,])