pairdist.default(spatstat)
pairdist.default()所属R语言包:spatstat
Pairwise distances
成对距离
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Computes the matrix of distances between all pairs of points in a set of points
计算在一组点在所有对点之间的距离的矩阵
用法----------Usage----------
## Default S3 method:
pairdist(X, Y=NULL, ..., period=NULL, method="C", squared=FALSE)
参数----------Arguments----------
参数:X,Y
Arguments specifying the coordinates of a set of points. Typically X and Y would be numeric vectors of equal length. Alternatively Y may be omitted and X may be a list with two components x and y, or a matrix with two columns.
引数,指定的一组点的坐标。通常情况下X和Y将数字向量的长度相等。或者Y可以省略,并且X可以是带有两个组件的列表x和y,或一个具有两列的矩阵。
参数:...
Ignored.
忽略。
参数:period
Optional. Dimensions for periodic edge correction.
可选。尺寸为周期的边缘校正。
参数:method
String specifying which method of calculation to use. Values are "C" and "interpreted". Usually not specified.
字符串,用于指定使用的计算方法。值是"C"和"interpreted"。通常没有指定。
参数:squared
Logical. If squared=TRUE, the squared distances are returned instead (this computation is faster).
逻辑。如果squared=TRUE,距离的平方返回,而不是(此计算速度更快)。
Details
详细信息----------Details----------
Given the coordinates of a set of points, this function computes the Euclidean distances between all pairs of points, and returns the matrix of distances. It is a method for the generic function pairdist.
给定的一组点的坐标,此函数计算所有对点之间的欧几里德距离,以及返回的距离矩阵。这是一个方法的通用函数pairdist。
The arguments X and Y must determine the coordinates of a set of points. Typically X and Y would be numeric vectors of equal length. Alternatively Y may be omitted and X may be a list with two components named x and y, or a matrix or data frame with two columns.
的参数中的X和Y必须确定的一组点的坐标。通常情况下X和Y将数字向量的长度相等。或者Y可以省略,并且X可能是一个名为x和y,或具有两列的矩阵或数据框的两个组件列表。
Alternatively if period is given, then the distances will be computed in the "periodic" sense (also known as "torus" distance). The points will be treated as if they are in a rectangle of width period[1] and height period[2]. Opposite edges of the rectangle are regarded as equivalent.
或者如果period给出,那么距离将被计算在定期感(也被称为环面的距离)。将被视为该点,如果他们是在一个矩形的宽度period[1]和高度period[2]。矩形的相对边缘被认为等同。
If squared=TRUE then the squared Euclidean distances d^2 are returned, instead of the Euclidean distances d. The squared distances are faster to calculate, and are sufficient for many purposes (such as finding the nearest neighbour of a point).
如果squared=TRUE然后的平方欧氏距离d^2返回,而不是的欧几里德距离d。距离的平方速度来计算,足够用于多种用途(如寻找最近的邻居的一个点)。
The argument method is not normally used. It is retained only for checking the validity of the software. If method = "interpreted" then the distances are computed using interpreted R code only. If method="C" (the default) then C code is used. The C code is somewhat faster.
参数method不能正常使用。它只会保留检查的软件的有效性。如果method = "interpreted"的距离计算仅使用解释R代码。如果method="C"(默认值),那么C代码使用。 C代码是稍快。
值----------Value----------
A square matrix whose [i,j] entry is the distance between the points numbered i and j.
一方阵的[i,j]项是点之间的距离编号i和j。
(作者)----------Author(s)----------
Pavel Grabarnik
<a href="mailto:pavel.grabar@issp.serpukhov.su">pavel.grabar@issp.serpukhov.su</a>
and
Adrian Baddeley
<a href="mailto:Adrian.Baddeley@csiro.au">Adrian.Baddeley@csiro.au</a>
<a href="http://www.maths.uwa.edu.au/~adrian/">http://www.maths.uwa.edu.au/~adrian/</a>
参见----------See Also----------
crossdist, nndist, Kest
crossdist,nndist,Kest
实例----------Examples----------
x <- runif(100)
y <- runif(100)
d <- pairdist(x, y)
d <- pairdist(cbind(x,y))
d <- pairdist(x, y, period=c(1,1))
d <- pairdist(x, y, squared=TRUE)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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