his ... hmmmm looks like your working with microarray data as well .... The actual matrix that I am working with is 19000 x 340 Thanks for the help, that was perfect. I am still getting used to the R language way of doing things.I will look into the apply function as you have written it. Peter At 12:22 AM 7/1/2004, Erin Hodgess wrote:>Hi Peter! > >Here is an example: > > > x > [,1] [,2] [,3] [,4] [,5] > [1,] 2.1632497 0.43219960 0.05329827 0.1484550 2.12996660 > [2,] 0.0000000 0.00000000 0.00000000 0.0000000 0.00000000 > [3,] -1.2230673 0.83467155 -0.14820752 -0.1012919 -0.04410457 > [4,] -0.5397403 0.92664487 -0.30390539 0.3105849 -0.69958321 > [5,] 1.0112805 1.13063148 -1.59802451 0.7597861 -0.72821421 > [6,] -1.1170756 -0.05128944 0.02755781 -0.8896866 0.12294861 > [7,] 0.0000000 0.00000000 0.00000000 0.0000000 0.00000000 > [8,] 0.7043937 0.82557039 -1.38759266 0.5266536 0.67345991 > [9,] 0.7522765 0.25513348 -1.00076227 0.1141770 1.70003769 >[10,] 0.3371948 -1.48590028 -0.67115529 -0.8242699 1.32741665 > > #This takes out the rows with ANY zeros > > x[!apply(x,1,function(x)any(x)==0),] > [,1] [,2] [,3] [,4] [,5] >[1,] 2.1632497 0.43219960 0.05329827 0.1484550 2.12996660 >[2,] -1.2230673 0.83467155 -0.14820752 -0.1012919 -0.04410457 >[3,] -0.5397403 0.92664487 -0.30390539 0.3105849 -0.69958321 >[4,] 1.0112805 1.13063148 -1.59802451 0.7597861 -0.72821421 >[5,] -1.1170756 -0.05128944 0.02755781 -0.8896866 0.12294861 >[6,] 0.7043937 0.82557039 -1.38759266 0.5266536 0.67345991 >[7,] 0.7522765 0.25513348 -1.00076227 0.1141770 1.70003769 >[8,] 0.3371948 -1.48590028 -0.67115529 -0.8242699 1.32741665 > > #This takes out the rows with ALL zeros > > x[!apply(x,1,function(x)all(x)==0),] > [,1] [,2] [,3] [,4] [,5] >[1,] 2.1632497 0.43219960 0.05329827 0.1484550 2.12996660 >[2,] -1.2230673 0.83467155 -0.14820752 -0.1012919 -0.04410457 >[3,] -0.5397403 0.92664487 -0.30390539 0.3105849 -0.69958321 >[4,] 1.0112805 1.13063148 -1.59802451 0.7597861 -0.72821421 >[5,] -1.1170756 -0.05128944 0.02755781 -0.8896866 0.12294861 >[6,] 0.7043937 0.82557039 -1.38759266 0.5266536 0.67345991 >[7,] 0.7522765 0.25513348 -1.00076227 0.1141770 1.70003769 >[8,] 0.3371948 -1.48590028 -0.67115529 -0.8242699 1.32741665 > > > > Hope this helps! > Sincerely, >Erin Hodgess >Associate Professor >Department of Computer and Mathematical Sciences >University of Houston - Downtown >mailto: hodgess at gator.uhd.edu > > > >From: Peter Wilkinson <pwilkinson at videotron.ca> >Subject: [R] how to drop rows from a data.frame > >here is a snippet of data where I would like to drop all rows that have >zeros across them, and keep the rest of the rows while maintaining the row >names (1,2,3, ...10). The idea here is that a row of zeros is an indication >that the row must be dropped. There will never be the case where there is a >row(of n columns) with less than 5 zeros in this case(n zeros > >I am unsure how to manipulate the data frame to drop rows whiles keeping >row names. > >Peter > >the data (imagine separated by tabs): > > SEKH0001 SEKH0002 SEKH0003 SEKH0004 SEKH0005 > [1,] 256.1139 256.1139 256.1139 256.1139 256.1139 > [2,] 283.0741 695.1000 614.5117 453.0342 500.1436 > [3,] 257.3578 305.0818 257.3578 257.3578 257.3578 > [4,] 0.0000 0.0000 0.0000 0.0000 0.0000 > [5,] 0.0000 0.0000 0.0000 0.0000 0.0000 > [6,] 0.0000 0.0000 0.0000 0.0000 0.0000 > [7,] 0.0000 0.0000 0.0000 0.0000 0.0000 > [8,] 257.0000 257.0000 257.0000 257.0000 257.0000 > [9,] 305.7857 2450.0417 335.5428 305.7857 584.2485 >[10,] 0.0000 0.0000 0.0000 0.0000 0.0000 > >what I want it to look like: > > SEKH0001 SEKH0002 SEKH0003 SEKH0004 SEKH0005 > [1,] 256.1139 256.1139 256.1139 256.1139 256.1139 > [2,] 283.0741 695.1000 614.5117 453.0342 500.1436 > [3,] 257.3578 305.0818 257.3578 257.3578 257.3578 > [8,] 257.0000 257.0000 257.0000 257.0000 257.0000 > [9,] 305.7857 2450.0417 335.5428 305.7857 584.2485 > >______________________________________________ >R-help at stat.math.ethz.ch mailing list >https://www.stat.math.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html