Hi, This is my first post. Problem: I have a matrix 5 by 5 and it has 3 NAs in them. Now, when i use length () for a particular column which has NA it returns 5. I know this is true, but how do i change my matrix such that the length becomes 5 minus the number of NAs i have. I know NA has a length of 1, but then how do i convert the NA into NULL whose length is 0. Thanks in advance. abid
try this: mat <- matrix(1:25, 5, 5) mat[sample(25, 3)] <- NA ######### mat colSums(!is.na(mat)) I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Syed Abid Hussaini" <ohitsabid at yahoo.com> To: <r-help at stat.math.ethz.ch> Sent: Wednesday, November 29, 2006 4:58 PM Subject: [R] Skip NA and alter length> Hi, > > This is my first post. > > Problem: > > I have a matrix 5 by 5 and it has 3 NAs in them. Now, when i use > length () for a particular column > which has NA it returns 5. I know this is true, but how do i change > my matrix such that the length > becomes 5 minus the number of NAs i have. I know NA has a length of > 1, but then how do i convert > the NA into NULL whose length is 0. > > Thanks in advance. > > abid > > ______________________________________________ > R-help at stat.math.ethz.ch 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. >Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
Thanks!! That did solve my problem. I am loving it. --- Dimitris Rizopoulos <dimitris.rizopoulos at med.kuleuven.be> wrote:> try this: > > mat <- matrix(1:25, 5, 5) > mat[sample(25, 3)] <- NA > ######### > mat > colSums(!is.na(mat)) > > > I hope it helps. > > Best, > Dimitris > > ---- > Dimitris Rizopoulos > Ph.D. Student > Biostatistical Centre > School of Public Health > Catholic University of Leuven > > Address: Kapucijnenvoer 35, Leuven, Belgium > Tel: +32/(0)16/336899 > Fax: +32/(0)16/337015 > Web: http://med.kuleuven.be/biostat/ > http://www.student.kuleuven.be/~m0390867/dimitris.htm > > > ----- Original Message ----- > From: "Syed Abid Hussaini" <ohitsabid at yahoo.com> > To: <r-help at stat.math.ethz.ch> > Sent: Wednesday, November 29, 2006 4:58 PM > Subject: [R] Skip NA and alter length > > > > Hi, > > > > This is my first post. > > > > Problem: > > > > I have a matrix 5 by 5 and it has 3 NAs in them. Now, when i use > > length () for a particular column > > which has NA it returns 5. I know this is true, but how do i change > > my matrix such that the length > > becomes 5 minus the number of NAs i have. I know NA has a length of > > 1, but then how do i convert > > the NA into NULL whose length is 0. > > > > Thanks in advance. > > > > abid > > > > ______________________________________________ > > R-help at stat.math.ethz.ch 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. > > > > > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm > >