# Triangular filled contour plot

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## Triangular filled contour plot

 Hi all, I am working on a filled contour plot which shows a triangular matrix data set (as shown below). Is there a possibilty to draw a triangular filled contour in a equilateral triangle (like a ternary plot)? Thanks in advance Johannes
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## Re: Triangular filled contour plot

 hello, maybe this code can be useful for you. cleber ----------------------- trimage <- function(f){ x = y = seq( 1, 0, l=181 ) t1 = length(x) im = aux = numeric(0) for( i in seq( 1, t1, by = 2 ) ){      #idx = seq( t1**2, i*t1, by = -t1 ) - ((t1 - i):0)      idx = seq( i*t1, t1**2, by = t1 ) - (i-1)      im = c(im, aux, idx, aux )      aux = c(aux, NA)      } z =  outer(X=x, Y=y, FUN=f) return( matrix(z[im],nr=t1) ) } ### for chemical mixtures ### restriction:   sum( x[i]==1 ) and  0 < x[i] < 1 ### naive example f <- function(x1,x2) { x3=1-x2-x1;  -100*x1 + 0*x2 + 100*x3 } windows(w=4.5, h=4.5, restoreConsole = TRUE ) par(mar=c(0,0,0,0), pty='s', xaxt='n', yaxt='n', bty='n' ) trimat <- trimage( f ) image( trimat ) contour( trimat, add=T) Em 16/2/2010 11:25, kajo escreveu: > Hi all, > > I am working on a filled contour plot which shows a triangular matrix data > set (as shown below). Is there a possibilty to draw a triangular filled > contour in a equilateral triangle (like a ternary plot)? > > Thanks in advance > Johannes > > http://n4.nabble.com/file/n1557386/Bild3.png>     -- O bom senso é a coisa do mundo mais bem distribuída: Todos pensamos tê-lo em tal medida que até os mais difíceis de contentar nas outras coisas não costumam desejar mais bom senso do que aquele que têm. [René Descartes] ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
 In reply to this post by kajo Johannes, Some months ago it was posted on R-help a list of packages that handle with ternaryplots, altough none of them can handle surfaceplots, just scatterplots, on a triangular area. The packages were plot.acomp in compositions tri in cwhmisc.cwhtool triax in plotrix ternary in StatDA ternaryplot in vcd ternaryplot in Zelig See http://n4.nabble.com/triangular-plot-td893434.html#a893435Due my needs I implemented something a little bit useful (at least to me) to make a prediction surface triangle plot using Lattice package. My reproducible code is the following: ```paint <- data.frame(mono=c(17.5, 10, 15, 25, 5, 5, 11.25, 5, 18.13, 8.13, 25, 15, 10, 5), cross=c(32.5, 40, 25, 25, 25, 32.5, 32.5, 40, 28.75, 28.75, 25, 25, 40, 25), resin=c(50, 50, 60, 50, 70, 62.5, 56.25, 55, 53.13, 63.13, 50, 60, 50, 70), hardness=c(29, 26, 17, 28, 35, 31, 21, 20, 29, 25, 19, 14, 30, 23)) pseudo <- with(paint, data.frame(mono=(mono-5)/(25-5), resin=(resin-50)/(70-50))) pseudo\$cross <- with(pseudo, 1-mono-resin) pseudo\$hardness <- paint\$hardness m1 <- lm(hardness~(mono+cross+resin)^2-mono, data=pseudo) trian <- expand.grid(base=seq(0,1,l=100*2), high=seq(0,sin(pi/3),l=87*2)) trian <- subset(trian, (base*sin(pi/3)*2)>high) trian <- subset(trian, ((1-base)*sin(pi/3)*2)>high) new2 <- data.frame(cross=trian\$high*2/sqrt(3)) new2\$resin <- trian\$base-trian\$high/sqrt(3) new2\$mono <- 1-new2\$resin-new2\$cross trian\$yhat <- predict(m1, newdata=new2) grade.trellis <- function(from=0.2, to=0.8, step=0.2, col=1, lty=2, lwd=0.5){ x1 <- seq(from, to, step) x2 <- x1/2 y2 <- x1*sqrt(3)/2 x3 <- (1-x1)*0.5+x1 y3 <- sqrt(3)/2-x1*sqrt(3)/2 panel.segments(x1, 0, x2, y2, col=col, lty=lty, lwd=lwd) panel.text(x1, 0, label=x1, pos=1) panel.segments(x1, 0, x3, y3, col=col, lty=lty, lwd=lwd) panel.text(x2, y2, label=rev(x1), pos=2) panel.segments(x2, y2, 1-x2, y2, col=col, lty=lty, lwd=lwd) panel.text(x3, y3, label=rev(x1), pos=4) } levelplot(yhat~base*high, trian, aspect="iso", xlim=c(-0.1,1.1), ylim=c(-0.1,0.96), xlab=NULL, ylab=NULL, contour=TRUE, par.settings=list(axis.line=list(col=NA), axis.text=list(col=NA)), panel=function(..., at, contour=TRUE, labels=NULL){ panel.levelplot(..., at=at, contour=contour, #labels=labels, lty=3, lwd=0.5, col=1) }) trellis.focus("panel", 1, 1, highlight=FALSE) panel.segments(c(0,0,0.5), c(0,0,sqrt(3)/2), c(1,1/2,1), c(0,sqrt(3)/2,0)) grade.trellis() panel.text(0, 0, label="mono", pos=2) panel.text(1/2, sqrt(3)/2, label="cross", pos=3) panel.text(1, 0, label="resin", pos=4) trellis.unfocus()```I think (and hope :-) ) Deepayan Sarkar will implement this on Lattice soon because R doesn't have this kind of graphic yet. My code isn't perfect so I expect suggestions. Walmes Zeviani, Brasil. ========================================================================== Walmes Marques Zeviani LEG (Laboratório de Estatística e Geoinformação, 25.450418 S, 49.231759 W) Departamento de Estatística - Universidade Federal do Paraná homepage: http://www.leg.ufpr.br/~walmes        twitter: @walmeszeviani ==========================================================================