Thanks very much. The cut function is exactly what I was looking for. For the graph I forgot to include an example (picture attached). I think it is something different from what you have shown in the examples. I want to plot all the data in a line plot - exactly how it is shown in the attached graph.
Mark ________________________________ From: R. Michael Weylandt <michael.weyla...@gmail.com> To: Mark D. <d.mar...@ymail.com> Cc: "r-help@r-project.org" <r-help@r-project.org> Sent: Saturday, 13 August 2011, 21:39 Subject: Re: [R] Plotting and quantiles I believe you received an informative answer to both these questions from Daniel Maiter one hour and twenty five minutes after sending your question: I repeat it here just in case you didn't get it. -------------------------- Q1 is very opaque because you are not even saying what kind of plot you want. For a regular scatterplot, you have multiple options. a.) select only the data in the given intervals and plot the data b.) plot the entire data, but restrict the graph region to the intervals you are interested in, or c.) winsorize the data (i.e., set values below the lower cutoff and above the upper cutoff to the cutoff values Which one you want to do depends on which one makes the most sense given the purpose of your analysis Say: x<-rnorm(100) y<-x+rnorm(100) Then a.) plot(y~x,data=data.frame(x,y)[ x<2&x>-2 , ]) #plots y against x only for xs between -2 and 2 b.) plot(y~x,xlim=c(-2,2)) #plots all y agains x, but restricts the plotting region to -2 to 2 on the x-axis c.) x<-replace(x,x>2,2) x<-replace(x,x<(-2),-2) plot(y~x) #sets all x-values below -2 and above 2 to these cutoffs Q2: look at the cut() function. ?cut HTH, Daniel --------------------- If you need more information, a different solution, or further clarification, please ask new questions. Michael Weylandt On Sat, Aug 13, 2011 at 10:10 AM, Mark D. <d.mar...@ymail.com> wrote: Dear R users, > > >This is most likely very basic question but I am new to R and would really >appreciate some tips on those two problems. > >1) I need to plot variables from a data frame. Because of some few high >numbers my graph is really strange looking. How could I plot a fraction of the >samples (like 0.1 (10%), 0.2 up to for example 0.6) on x axis and values >'boundaries' (like any value '< 100', '101-200' and '> 201') on the y axis? >This needs to be a simple line plot like the one I attached for an example. >The values would come from one column. > > >2) I have a data frame with values and need to subset the rows based on the >values. I wanted to order them (with increasing values) and divide into 3-4 >groups. I though about using quantile but I want the group to be something >like '1-25', '26-50', '51-75', '75-100' (ordered and for example 25th >percentile, 26-50th etc). I could just look for a median divide into two and >then again (or use quantiles 0.25, 0.5, 0.7 and 1 and then get rid of all rows >in 0.25 that are in 0.5 etc) but surely there must by a faster and simpler way >to do that (I need to do this a lot on different columns)? > >Thanks for your help, >Mark >______________________________________________ >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. > >
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______________________________________________ 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.
