dist.xyz: Calculate the Distances Between the Rows of Two Matrices
Description
Compute the pairwise euclidean distances between the rows of two matrices.
Usage
dist.xyz(a, b = NULL, all.pairs=TRUE, ncore=1, nseg.scale=1)
Value
Returns a matrix of pairwise euclidean distances between each row of
‘a’ and all rows of ‘b’.
Arguments
a
a ‘xyz’ object, numeric data matrix, or vector.
b
an optional second ‘xyz’ object, data matrix, or vector.
all.pairs
logical, if TRUE all pairwise distances between the
rows of ‘a’ and all rows of ‘b’ are computed, if FALSE
only the distances between coresponding rows of ‘a’ and
‘b’ are computed.
ncore
number of CPU cores used to do the calculation.
ncore>1 requires package ‘parallel’ installed.
nseg.scale
split input data into specified number of segments
prior to running multiple core calculation. See fit.xyz.
Author
Barry Grant
Details
This function returns a matrix of euclidean distances between each row
of ‘a’ and all rows of ‘b’. Input vectors are
coerced to three dimensional matrices (representing the Cartesian
coordinates x, y and z) prior to distance computation. If ‘b’ is
not provided then the pairwise distances between all rows of ‘a’
are computed.
References
Grant, B.J. et al. (2006) Bioinformatics22, 2695--2696.