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[matrix] Diff of /pkg/man/tcrossprod.Rd
 [matrix] / pkg / man / tcrossprod.Rd

Diff of /pkg/man/tcrossprod.Rd

revision 675, Sat Mar 26 11:16:05 2005 UTC revision 823, Sat Jul 30 21:35:38 2005 UTC
# Line 3  Line 3
3  \alias{tcrossprod-methods}  \alias{tcrossprod-methods}
4  \alias{tcrossprod,dgCMatrix-method}  \alias{tcrossprod,dgCMatrix-method}
5  \alias{tcrossprod,dgTMatrix-method}  \alias{tcrossprod,dgTMatrix-method}
6    \alias{tcrossprod,matrix-method}
7    \alias{tcrossprod,numeric-method}
8    % more \alias{tcrossprod,...}es in *-class*.Rd files
9  \alias{tcrossprod}  \alias{tcrossprod}
10  \title{Cross-product of transpose}  \title{Cross-product of transpose}
11  \description{  \description{
# Line 41  Line 44
44   object.size(m) / object.size(mm) # smaller by a factor of 242.88   object.size(m) / object.size(mm) # smaller by a factor of 242.88
45
46   ## tcrossprod() is very fast:   ## tcrossprod() is very fast:
47   system.time(tCmm <- tcrossprod(mm))# "0" practically   system.time(tCmm <- tcrossprod(mm))# 0   (PIII, 933 MHz)
48   system.time(cm <- crossprod(t(m))) #   system.time(cm <- crossprod(t(m))) # 0.16
49     system.time(cm. <- tcrossprod(m))  # 0.02
50
51   stopifnot(identical(cm, as(tCmm, "matrix")))   stopifnot(identical(cm, as(tCmm, "matrix")))
52

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