> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Doran, Harold > Sent: Tuesday, August 14, 2012 10:27 AM > To: Doran, Harold; 'r-help@r-project.org' > Subject: Re: [R] Communative Matrix Multiplcation > > Meant to also add > > library(Matrix) > > for reproducing > > From: Doran, Harold > Sent: Tuesday, August 14, 2012 1:26 PM > To: r-help@r-project.org > Subject: Communative Matrix Multiplcation > > Friends > > I'm not seeing why the following occurs: > > > T1 <- (A1 - A2) %*% D > > T2 <- (A1 %*% D) - (A2 %*% D) > > identical(T1, T2) > [1] FALSE > > Harold > > > dput(A1) > new("dsCMatrix" > , i = c(0L, 1L, 2L, 3L, 0L, 1L, 4L, 2L, 3L, 5L) > , p = c(0L, 1L, 2L, 3L, 4L, 7L, 10L) > , Dim = c(6L, 6L) > , Dimnames = list(NULL, NULL) > , x = c(5, 5, 5, 5, 5, 5, 10, 5, 5, 10) > , uplo = "U" > , factors = list() > ) > > dput(A2) > new("dgeMatrix" > , x = c(1.41313955042629, 1.23647532592053, 1.36413787785255, > 0.986247245800629, > 2.64961487634682, 2.35038512365318, 1.23647532592053, 1.55872699943971, > 0.579347997632991, 1.62544967700677, 2.79520232536024, > 2.20479767463976, > 1.36413787785255, 0.579347997632991, 2.75106274522123, > 0.305451379293231, > 1.94348587548554, 3.05651412451446, 0.986247245800629, > 1.62544967700677, > 0.305451379293232, 2.08285169789937, 2.6116969228074, 2.3883030771926, > 2.64961487634682, 2.79520232536024, 1.94348587548554, 2.6116969228074, > 5.44481720170706, 4.55518279829294, 2.35038512365318, 2.20479767463976, > 3.05651412451446, 2.3883030771926, 4.55518279829294, 5.44481720170706 > ) > , Dim = c(6L, 6L) > , Dimnames = list(NULL, NULL) > , factors = list() > ) > > dput(D) > new("ddiMatrix" > , diag = "N" > , Dim = c(6L, 6L) > , Dimnames = list(NULL, NULL) > , x = c(5, 5, 5, 5, 10, 10) > ) >
Probably FAQ 7.31. Try all.equal(T1,T2) Hope this is helpful, Dan Daniel J. Nordlund Washington State Department of Social and Health Services Planning, Performance, and Accountability Research and Data Analysis Division Olympia, WA 98504-5204 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
