sparseLU-class(Matrix)
sparseLU-class()所属R语言包：Matrix
Sparse LU decomposition of a square sparse matrix
一个正方形的稀疏矩阵稀疏LU分解
译者：生物统计家园网 机器人LoveR
描述----------Description----------
Objects of this class contain the components of the LU
这个类的对象包含陆组件
类的对象----------Objects from the Class----------
Objects can be created by calls of the form new("sparseLU", ...) but are more commonly created by function lu() applied to a sparse matrix, such as a matrix of class dgCMatrix.
对象可以创建调用的形式new("sparseLU", ...)但更常见的功能lu()如类dgCMatrix矩阵，稀疏矩阵的创建。
插槽----------Slots----------
L: Object of class "dtCMatrix", the lower
L：Object类的"dtCMatrix"，低
U: Object of class "dtCMatrix", the upper
U：Object类的"dtCMatrix"，上
p: Object of class "integer", permutation
p类"integer"，置换对象
q: Object of class "integer", permutation
q类"integer"，置换对象
Dim: the dimension of the original matrix; inherited
Dim：继承原始矩阵的维数;
延伸----------Extends----------
Class "LU", directly. Class "MatrixFactorization", by class "LU".
类"LU"，直接。类"MatrixFactorization"类"LU"。
方法----------Methods----------
expand signature(x = "sparseLU") Returns a list with components P, L, U, and Q, where P and Q represent fill-reducing permutations, and L, and U the lower and upper triangular matrices of the decomposition. The original matrix
扩大signature(x = "sparseLU")返回组件列表P，L，U，Q，其中P和Q代表填写排列，减少和L，U分解上下三角矩阵原矩阵
注意----------Note----------
The decomposition is of the form
分解的形式是
where all matrices are sparse and of size n by n. The matrices P, its transpose P', and Q are permutation matrices, L is lower triangular and U is upper triangular.
所有矩阵都是稀疏的大小n by n。矩阵P，其转P'，Q置换矩阵，L是下三角和U是上三角。
参见----------See Also----------
lu, solve, dgCMatrix
lu，solve，dgCMatrix
举例----------Examples----------
## Extending the one in examples(lu), calling the matrix A,[＃扩展的一个例子（LU），调用矩阵A，]
## and confirming the factorization identities :[＃分解身份确认：]
A <- as(readMM(system.file("external/pores_1.mtx",
package = "Matrix")),
"CsparseMatrix")
str(luA <- lu(A)) # p is a 0-based permutation of the rows[p为0的行基于置换]
# q is a 0-based permutation of the columns[q是一列0基于置换]
xA <- expand(luA)
## which is simply doing[＃这是简单地做]
stopifnot(identical(xA$ L, luA@L),
identical(xA$ U, luA@U),
identical(xA$ P, as(luA@p +1L, "pMatrix")),
identical(xA$ Q, as(luA@q +1L, "pMatrix")))
P.LUQ <- with(xA, t(P) %*% L %*% U %*% Q)
stopifnot(all.equal(A, P.LUQ, tol = 1e-12))
## permute rows and columns of original matrix[＃置位的原矩阵的行和列]
pA <- A[luA@p + 1L, luA@q + 1L]
stopifnot(identical(pA, with(xA, P %*% A %*% t(Q))))
pLU <- drop0(luA@L %*% luA@U) # L %*% U -- dropping extra zeros[％L *％铀 - 删除多余的零]
stopifnot(all.equal(pA, pLU))
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注：
注1：为了方便大家学习，本文档为生物统计家园网机器人LoveR翻译而成，仅供个人R语言学习参考使用，生物统计家园保留版权。
注2：由于是机器人自动翻译，难免有不准确之处，使用时仔细对照中、英文内容进行反复理解，可以帮助R语言的学习。
注3：如遇到不准确之处，请在本贴的后面进行回帖，我们会逐渐进行修订。
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发表于 2012-2-16 17:30:55
