Hello, I have a graphics-related question: I was wondering if anyone knows of a way to create a bar chart that is colored with a three-part gradient that changes at fixed y-values. Each bar needs to fade green-to-yellow at Y=.10 and from yellow-to-red at Y=.20. Is there an option in a package somewhere that offers an easy way to do this? Attached is a chart I macgyvered together in Excel using a combination of a simple bar chart, fit line, and some drawing tools. I want to avoid doing it this way in the future by finding a way to replicate it in R. Any ideas? Thanks, Jason Michael Rodriguez Data Analyst State Housing Trust Fund for the Homeless Georgia Department of Community Affairs Email: jason.rodriguez at dca.ga.gov -------------- next part -------------- A non-text attachment was scrubbed... Name: Unknown outcomes chart 120410.pdf Type: application/pdf Size: 116248 bytes Desc: Unknown outcomes chart 120410.pdf URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20120409/5c6db8a7/attachment.pdf>
Gradients in bar charts XXXX
4 messages · Jason Rodriguez, ilai, Jim Lemon +1 more
On Mon, Apr 9, 2012 at 12:40 PM, Jason Rodriguez
<Jason.Rodriguez at dca.ga.gov> wrote:
Hello, I have a graphics-related question: I was wondering if anyone knows of a way to create a bar chart that is colored with a three-part gradient that changes at fixed y-values. Each bar needs to fade green-to-yellow at Y=.10 and from yellow-to-red at Y=.20. Is there an option in a package somewhere that offers an easy way to do this?
?rainbow ?hsv
In R "an easy way" is an ill-defined term. In the absence of actual data:
bpd <- matrix(c(1,seq(0,1,l=64),2,1,seq(0,1,l=64),5,1,seq(0,1,l=64),7),nc=3)
mycols <- c('green',rainbow(64,start=0,end=.4)[64:1],'red')
barplot(bpd,col=mycols,border=NA)
"Easy" enough ?
Cheers
Attached is a chart I macgyvered together in Excel using a combination of a simple bar chart, fit line, and some drawing tools. I want to avoid doing it this way in the future by finding a way to replicate it in R. Any ideas? Thanks, Jason Michael Rodriguez Data Analyst State Housing Trust Fund for the Homeless Georgia Department of Community Affairs Email: ?jason.rodriguez at dca.ga.gov
______________________________________________ R-help at 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.
On 04/10/2012 04:40 AM, Jason Rodriguez wrote:
Hello, I have a graphics-related question: I was wondering if anyone knows of a way to create a bar chart that is colored with a three-part gradient that changes at fixed y-values. Each bar needs to fade green-to-yellow at Y=.10 and from yellow-to-red at Y=.20. Is there an option in a package somewhere that offers an easy way to do this? Attached is a chart I macgyvered together in Excel using a combination of a simple bar chart, fit line, and some drawing tools. I want to avoid doing it this way in the future by finding a way to replicate it in R. Any ideas?
Hi Jason, When I first read your message, I immediately thought of using gradient.rect (plotrix). With a bit of recoding, the barp function (also in plotrix) could use gradient.rect instead of rect. The trick would be to create a vector of colors that would fill the tallest bar and pass that as "col". Only the colors that are necessary to fill each bar will actually be displayed. To get such a vector, stick together sequences of constant colors plus sequences from the color.scale function (or similar) for the fades. Once you have created the vector of desired colors, you can just pass that. I think this would be a custom function you could program unless lots of people leap up in joy at the thought of such a bar plot. Jim
3 days later
Here is one approach:
tmp <- rbinom(10, 100, 0.78)
mp <- barplot(tmp, space=0, ylim=c(0,100))
tmpfun <- colorRamp( c('green','yellow',rep('red',8)) )
mat <- 1-row(matrix( nrow=100, ncol=10 ))/100
tmp2 <- tmpfun(mat)
mat2 <- as.raster( matrix( rgb(tmp2, maxColorValue=255), ncol=10) )
for(i in 1:10) mat2[ mat[,i] >= tmp[i]/100, i] <- NA
rasterImage(mat2, mp[1] - (mp[2]-mp[1])/2, 0, mp[10] + (mp[2]-mp[1])/2, 100,
interpolate=FALSE)
barplot(tmp, col=NA, add=TRUE, space=0)
You can tweak it to your desire. It might look a little better if
each bar were drawn independently with interpolate=TRUE (this would
also be needed if you had space between the bars).
On Mon, Apr 9, 2012 at 12:40 PM, Jason Rodriguez
<Jason.Rodriguez at dca.ga.gov> wrote:
Hello, I have a graphics-related question: I was wondering if anyone knows of a way to create a bar chart that is colored with a three-part gradient that changes at fixed y-values. Each bar needs to fade green-to-yellow at Y=.10 and from yellow-to-red at Y=.20. Is there an option in a package somewhere that offers an easy way to do this? Attached is a chart I macgyvered together in Excel using a combination of a simple bar chart, fit line, and some drawing tools. I want to avoid doing it this way in the future by finding a way to replicate it in R. Any ideas? Thanks, Jason Michael Rodriguez Data Analyst State Housing Trust Fund for the Homeless Georgia Department of Community Affairs Email: ?jason.rodriguez at dca.ga.gov
______________________________________________ R-help at 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.
Gregory (Greg) L. Snow Ph.D. 538280 at gmail.com