[R] barplot() x axes are not updated after removal of categories from the dataframe
Hi all, I'd be grateful for your help. I am a new user struggling with a barplot issue. I am plotting categories (X axis) and their mean count (Y axies) with barplot(). The first call to barplot works fine. I remove records from the dataframe using final=[!final$varname == some value,] I echo the dataframe and the records are no longer in the dataframe. When I call plot again however, the X axis still contains the removed category values albeit with a count of 0. How can I stop the removed categories appearing in the barplot? Are they stored globally after the first barplot call? thanks in advance for your help. R [[alternative HTML version deleted]] __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] barplot() x axes are not updated after removal of categories from the dataframe
on 02/12/2009 06:35 AM R User R User wrote: Hi all, I'd be grateful for your help. I am a new user struggling with a barplot issue. I am plotting categories (X axis) and their mean count (Y axies) with barplot(). The first call to barplot works fine. I remove records from the dataframe using final=[!final$varname == some value,] I echo the dataframe and the records are no longer in the dataframe. When I call plot again however, the X axis still contains the removed category values albeit with a count of 0. How can I stop the removed categories appearing in the barplot? Are they stored globally after the first barplot call? thanks in advance for your help. R When you subset a factor, the unused levels are not removed by default. This is intentional to preserve these characteristics for subsequent operations such as modeling. You are presumably using something like: table(final$varname) to create the counts used in barplot(). As an example, using the iris dataset: table(iris$Species) setosa versicolor virginica 50 50 50 iris2 - subset(iris, Species != setosa) table(iris2$Species) setosa versicolor virginica 0 50 50 Note that even though I removed records from iris where Species == setosa, it still shows in the table. You would need to do the following: iris2$Species - factor(iris2$Species) table(iris2$Species) versicolor virginica 50 50 Using factor() on the column removes the unused levels. See ?[.factor for more information. HTH, Marc Schwartz __ 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.
Re: [R] barplot() x axes are not updated after removal of categories from the dataframe
R User R User ruser2008 at googlemail.com writes: I am plotting categories (X axis) and their mean count (Y axies) with barplot(). The first call to barplot works fine. I remove records from the dataframe using final=[!final$varname == some value,] I echo the dataframe and the records are no longer in the dataframe. When I call plot again however, the X axis still contains the removed category values albeit with a count of 0. How can I stop the removed categories appearing in the barplot? Are they stored globally after the first barplot call? It has do do with non-dropped factors. See http://markmail.org/message/qdgjpuzcfia3xm6p Create a new factor with the levels dropped. Dieter __ 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.
