Re: [R] Remove NAs from Barplot

From: Marc Schwartz (via MN) <mschwartz_at_mn.rr.com>
Date: Thu 25 Aug 2005 - 03:29:21 EST

On Wed, 2005-08-24 at 13:06 -0400, Doran, Harold wrote:
> Dear List:
>
> I'm creating a series of barplots using Sweave that must assume a
> standard format. This is student achievement data and the x-axis must
> include all grades 3 to 8. In some cases, the data for a grade (or more
> than one grade) are missing in the vector math.bar, but are never
> missing for the vector apmxpmeet. The following sample code illustrates
> the issue.
>
> Using the code below to create the plot works fine. However, the
> following command is designed to place the data onto the plot:
>
> text(math.barplot, graph.max+5, format(tot), xpd = TRUE, col = c("blue",
> "orange") )
>
> This does work, but, it also places 'NA's on the plot. Is there a way to
> place the data onto the plot such that the numbers appear, but for the
> NAs not to appear? I've searched through ?text but was not able to find
> a solution.
>
> math.bar <- c(NA,NA,NA,NA,55,48)
> apmxpmeet <- c(47, 50, 49, 50, 49, 46)
>
> par(ps=10)
> math.bar <- rbind(math.bar, apmxpmeet)
> math.barplot <- barplot(math.bar, beside=T, col=c('blue','orange'),
> names=c('Grade \n 3','Grade \n 4','Grade \n 5','Grade \n 6','Grade \n
> 7','Grade \n 8'),
> ylim=c(0,120), ylab="Percentage", xlab="Grade Level")
> tot <- round(math.bar,digits=0)
> graph.max <- max(math.bar, apmxpmeet, na.rm=T)
> text(math.barplot, graph.max+5, format(tot), xpd = TRUE, col = c("blue",
> "orange") )
> tmp$sch_nameS05 <- as.character(tmp$sch_nameS05)
> legend(2,120,legend=(c(tmp$sch_nameS05, "Average")),
> fill=c("blue","orange"))
>
> Thanks,
> Harold

Harold,

Get rid of the 'format(tot)' in your text() call:

text(math.barplot, graph.max+5, tot, xpd = TRUE,

     col = c("blue", "orange"))

By using format(tot), you are coercing the values to text. Thus:

> format(tot)

          [,1] [,2] [,3] [,4] [,5] [,6]
math.bar "NA" "NA" "NA" "NA" "55" "48"
apmxpmeet "47" "50" "49" "50" "49" "46"

versus:

> tot

          [,1] [,2] [,3] [,4] [,5] [,6]
math.bar NA NA NA NA 55 48
apmxpmeet 47 50 49 50 49 46

In the first case, text() will draw "NA", whereas in the second, the NA is ignored.

Also, your code above is not entirely reproducible, since:

> tmp$sch_nameS05 <- as.character(tmp$sch_nameS05)
Error: Object "tmp" not found

HTH, Marc Schwartz



R-help@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 Received on Thu Aug 25 03:36:43 2005

This archive was generated by hypermail 2.1.8 : Sun 23 Oct 2005 - 15:50:19 EST