I have a matrix 700x2000 which is sampled in each cycle from another matrix 788x2000 with the numbers 0,1 and 9 There is one specific collumn of this matrix, dart[,1977], that usually, after the samplimg procedure has only 1 and 9 (because the zero frequency in this collumn is low). However, when this happens, I want to include an IF conditional in my code. so basically what i wanted to do was to count the number of zeros in this collumn to use this information in my conditional: something like: if (the number of zeros in collumn [,1977] is zero) ... else ... I tried to find out indirectly by the rowsum but because of the sampling procedure the rowsum is not always the same Thank you very much -- View this message in context: http://www.nabble.com/Count-number-of-zeros-in-a-collumn-tp25637516p25637516.html Sent from the R help mailing list archive at Nabble.com.
Hi Marcio, How about if (min(dart[,1977])==0)... cheers milton On Sun, Sep 27, 2009 at 4:54 PM, Marcio Resende <mresendeufv@yahoo.com.br>wrote:> > I have a matrix 700x2000 which is sampled in each cycle from another matrix > 788x2000 with the numbers 0,1 and 9 > > There is one specific collumn of this matrix, dart[,1977], that usually, > after the samplimg procedure has only 1 and 9 (because the zero frequency > in > this collumn is low). > However, when this happens, I want to include an IF conditional in my code. > so basically what i wanted to do was to count the number of zeros in this > collumn to use this information in my conditional: > > something like: > > if (the number of zeros in collumn [,1977] is zero) ... else ... > > I tried to find out indirectly by the rowsum but because of the sampling > procedure the rowsum is not always the same > > Thank you very much > -- > View this message in context: > http://www.nabble.com/Count-number-of-zeros-in-a-collumn-tp25637516p25637516.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. >[[alternative HTML version deleted]]
more generally, if you want to test for some minimum threshold T on the number of zeros, try:> if(length(which(dart[,1977] == 0)) < T) { # some code to handle the too-few-zeros-case }On Sep 27, 4:54?pm, Marcio Resende <mresende... at yahoo.com.br> wrote:> I have a matrix 700x2000 which is sampled in each cycle from another matrix > 788x2000 with the numbers 0,1 and 9 > > There is one specific collumn of this matrix, dart[,1977], that usually, > after the samplimg procedure has only 1 and 9 (because the zero frequency in > this collumn is low). > However, when this happens, I want to include an IF conditional in my code. > so basically what i wanted to do was to count the number of zeros in this > collumn to use this information in my conditional: > > something like: > > if (the number of zeros in collumn [,1977] is zero) ... else ... > > I tried to find out indirectly by the rowsum but because of the sampling > procedure the rowsum is not always the same > > Thank you very much > -- > View this message in context:http://www.nabble.com/Count-number-of-zeros-in-a-collumn-tp25637516p2... > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.