Hi Rui, Yes, I see. You are right. Thanks for your help. Zhengyu > Date: Wed, 3 Jul 2013 22:38:37 +0100 > From: ruipbarra...@sapo.pt > To: zhyjiang2...@hotmail.com > CC: r-help@r-project.org > Subject: Re: [R] change cell values > > Hello, > > It's not working because you are changing mat1 before the second > condition is evaluated, and so mat1 is full of NA values. Try the following. > > > > tmp <- mat1 # Make a copy > tmp[mat1 < 1 & mat2 < 1] <- NA # And change that copy > mat2[mat1 < 1 & mat2 < 1] <- NA > mat1 <- tmp > rm(tmp) > > > Hope this helps, > > Rui Barradas > > Em 03-07-2013 22:27, JiangZhengyu escreveu: > > > > > > > > Dear R experts, > > > > I have two matrices (mat1 & mat2) with the same dimension & the cells (row > > and column) are corresponding to each other. > > > > I want to change cell values to NA given values of the corresponding cells > > in mat1 and mat2 are both <1. > > > > E.g. both mat1[2,3] and mat2[2,3] are <1, I will put mat1[2,3]=NA, and > > mat2[2,3]=NA; if either mat1[2,3]>=1 or mat2[2,3]>=1, I will save both > > cells. > > > > I tried the code, but not working. Could anyone can help fix the problem? > > > > mat1[mat1<1&mat2<1]=NA > > mat2[mat1<1&mat2<1]=NA > > > > > >> mat1=matrix(rnorm(12),3) > >> mat2=matrix(rnorm(12),3) > >> mat1 > > [,1] [,2] [,3] [,4] > > [1,] -1.3387075 -0.7142333 -0.5614211 0.1846955 > > [2,] -0.7936087 -0.2215797 -0.3686067 0.7328731 > > [3,] 0.6505082 0.1826019 1.5577883 -1.5580384 > >> mat2 > > [,1] [,2] [,3] [,4] > > [1,] 0.4331573 -1.8086826 -1.7688123 -1.4278934 > > [2,] -0.1841451 0.1738648 -1.1086942 1.3065109 > > [3,] -1.0827245 -0.4143808 -0.6889405 0.4046203 > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > 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. > > [[alternative HTML version deleted]]
______________________________________________ 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.
