dist2(genefilter)
dist2()所属R语言包:genefilter
Calculate an n-by-n matrix by applying a function to pairs of columns of an m-by-n matrix.
N-n矩阵计算应用功能,对一个m-n矩阵的列。
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Calculate an n-by-n matrix by applying a function to pairs of columns of an m-by-n matrix.
N-n矩阵计算应用功能,对一个m-n矩阵的列。
用法----------Usage----------
dist2(x, fun=function(a,b) mean(abs(a-b), na.rm=TRUE), diagonal=0)
参数----------Arguments----------
参数:x
A matrix, or any object x for which ncol(x) and x[,j] return appropriate results.
A矩阵,或任何对象xncol(x)和x[,j]返回相应的结果。
参数:fun
A symmetric function of two arguments that may be columns of x.
对称函数的两个参数,可能是x列。
参数:diagonal
The value to be used for the diagonal elements of the resulting matrix.
用于矩阵对角线元素的值。
Details
详情----------Details----------
With the default value of fun, this function calculates for each pair of columns of x the mean of the absolute values of their differences (which is proportional to the L1-norm of their difference). This is a distance metric.
fun的默认值,这个函数计算每列x他们之间的分歧(这是它们的区别L1范数的比例)的绝对值的平均值。这是一个距离度量。
The implementation assumes that fun is symmetric, fun(a,b)=fun(b,a). Hence, the returned matrix is symmetric. fun(a,a) is not evaluated, instead the value of diagonal is used to fill the diagonal elements of the returned matrix.
实现假定fun是对称的,fun(a,b)=fun(b,a)。因此,返回矩阵是对称的。 fun(a,a)没有被评估,而不是diagonal用于填充返回的矩阵对角线元素的值。
A use for this function is the detection of outlier arrays in a microarray experiment. Assume that each column of x can be decomposed as z+β+ε, where z is a fixed vector (the same for all columns), ε is vector of nrow{x} i.i.d. random numbers, and β is an arbitrary vector whose majority of entries are negligibly small (i.e. close to zero). In other words, Dz the probe effects, ε measurement
使用此功能是在芯片实验检测离群阵列。假设每列x可以分解为z+β+ε,其中z是一个固定的向量(所有列相同),εnrow{x}向量IID随机数,和β是一个任意的向量,其多数的条目是可以忽略不计的小(即接近零)。换句话说,Dz探针的影响,ε测量
noise and β differential expression effects. Under this assumption, all entries of the resulting distance matrix should be the same, namely a multiple of the standard deviation of ε. Arrays whose distance matrix entries are way different give cause for suspicion.
噪声和β差异表达的影响。根据这一假设,所有参赛作品所产生的距离矩阵应该是相同的,即多个ε的标准偏差。阵列的距离矩阵条目的方式不同,给怀疑的原因。
值----------Value----------
A symmetric matrix of size n x n.
对称矩阵的大小n x n。
举例----------Examples----------
z = matrix(rnorm(15693), ncol=3)
dist2(z)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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