Re: [R] Plot Coloured Triangle

From: Antje <niederlein-rstat_at_yahoo.de>
Date: Tue, 10 Jun 2008 11:21:23 +0200

Thank you very much!
That's exactly what I need as a starting point :-)

Antje

Greg Snow schrieb:
> Here is an example that may get you started:
>
> point1 <- c(1.1, 1.7, 255)
> point2 <- c(2.2, 1.5, 180)
> point3 <- c(1.8, 2.2, 60)
>
> mydf <- as.data.frame( rbind(point1, point2, point3) )
> names(mydf) <- c('x1','x2','red')
>
> fit <- lm(red~x1+x2, data=mydf)
>
> df2 <- expand.grid( x1=seq(min(mydf$x1), max(mydf$x1), length=250),
> x2=seq(min(mydf$x2), max(mydf$x2), length=250) )
>
> df2$red <- predict(fit, df2)
>
> library(sp)
> tmp <- point.in.polygon( df2$x1, df2$x2, mydf$x1, mydf$x2)
>
> df2$red[ tmp==0 ] <- NA
>
> reds <- sort(unique(df2$red))
> cols <- rgb(reds, 0, 0, maxColorValue=255)
>
> library(lattice)
> levelplot( red~x1+x2, data=df2, col.regions=cols )
>
>
> --
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow_at_imail.org
> (801) 408-8111
>
>
>

>> -----Original Message-----
>> From: r-help-bounces_at_r-project.org
>> [mailto:r-help-bounces_at_r-project.org] On Behalf Of Antje
>> Sent: Monday, June 09, 2008 2:57 AM
>> To: r-help_at_stat.math.ethz.ch
>> Subject: [R] Plot Coloured Triangle
>>
>> Hi there,
>>
>> I'd like to plot a triangle with each point having a certain
>> color defined and fill it with the interpolated values.
>> The following code shall represent somehow, three points with
>> x,y, and the "amount" of red for example...
>>
>> point1 <- c(1.1, 1.7, 255)
>> point2 <- c(2.2, 1.5, 180)
>> point3 <- c(1.8, 2.2, 60)
>>
>> can anybody give me a hint which methods to use to realize it?
>>
>> Antje
>>
>> ______________________________________________
>> 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.
>>

>

>

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. Received on Tue 10 Jun 2008 - 10:21:56 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 10 Jun 2008 - 12:30:38 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive