Hi all, I'm trying to plot colour as a fourth variable onto a persp plot to highlight the multiple modes in my dataset. A plot with 3 variables (frequency, time and depth) has been created using the code below: require(MASS) require(graphics) require(plot3D) require(pdfCluster) ## density estimate and persp plot with 3 variables f1 <- kde2d(Max_d, Bottom_t, n=124, lims=c(0, 90, 0, 140)) persp(f1, phi = 40, theta = 50, d = 5, col="lightblue", xlab="Maximum diving depth, m", ylab="Bottom time, m", zlab="Number of dives") # f1$x represents depth - vector - length 124 # f1$y represents bottom time (duration) - vector - length 124 # f1$z is the frequency matrix - length 15375 (124 by 124 Matrix) The colour variable has been produced as a vector (length 124) using a cluster analysis ## Colour variable - representing 3 modes within the data (1,2&3 in g_class1) test1 <- Penguins[,c(16, 11)] test1a <- pdfCluster(test1, graphtype="delaunay", h=h.norm(test1), hmult=1.2, options="Qt", kernel="gaussian", bwtype="fixed") g_class1 <-groups(test1a, stage=5) g1 <- data.frame(g_class1) Penguins3 <- data.frame(c(Penguins, g1, f1)) ## using persp3D and colvar to get colour plotted persp3D(z=f1$z, x=f1$x, y=f1$y, bty="bl2", axes=T, facets=NA, colvar=Penguins3$g_class1, lighting=T, colkey=TRUE, xlab="Maximum depth", ylab="Bottom_time", zlab="Number of dives",xlim=c(0,90), ylim=c(0,140), ticktype="detailed", border=NA) # error - as colvar is not equal in dimensions to matrix Z. ggg1 <- matrix(Penguins3$g_class1, nrow=124, ncol=124) persp3D(z=f1$z, x=f1$x, y=f1$y, bty="b2", axes=T, colvar=ggg1, colkey=TRUE, xlab="Maximum depth", ylab="Bottom_time", zlab="Number of dives",xlim=c(0,90), ylim=c(0,140), ticktype="detailed", border=NA) # produces the chart but values are (obviously) wrong I understand that my current colour variable is a vector when I actually need a matrix, but I'm unsure how to get around this issue as the vector length is 124 and the matrix I need would be 124X124. Is there anyway to plot the colour as a variable over the perspective plot? Thanks in advance, Chelsea [[alternative HTML version deleted]]