similar to: question in value-based color in image()

Hello, I have a matrix A with value varying from -1 to 1. I hope to use scaled color based on its value to produce an image of this matrix. Suppose I hope to label those data in [-1,-0.5] with blue, label those [-0.5,0.8] with light blue (tone is proportional to its value, e.g. rgb(1-tone, 1-tone, 1) where tone=abs(A)/0.5), and label those [0.8,1] with white. How can I use image() and rgb() to

I have a JPEG map of temperature data, coded using a given legend where blues are cooler and reds hotter. Is there any preexisting R magic or package which might let me recover the value of the scalar quantity so represented given the RGB values at each point in the picture? After processing, I'd also like to push the results back through the translate to get an RGB JPEG again. Thanks for

I have a diagram to be included in latex, where all my figures are .eps graphics (so pdflatex is not an option) and I want to achieve something like the following: three concentric filled circles varying in lightness or saturation. It is easiest to do this using transparency, but in my test using the postscript driver, the transparent color fills do not appear. Is it correct that postscript()

Hi Listers, Is it possible to produce an ordination plot in 2d, where bubbles represent the location of sites (this part is easy enough) and the size of the bubbles is proportional to the sites location in 3d space (I am stuck on this option). So sites that are very near the 2d plane of the xy axes would be larger while sites that are actually further away in 3 d space would be proportionally

Dear R users, I have a 51 by 51 matrix of p-values (named as pvalue_MA). I want to present graphically this matrix in a plot (filled contour plot) where both axes represent probabilities. I have also added a grid in this plot. I want to highlight in white the cells of the grid that represent p-values smaller than the (common) significance threshold, 0.05. The code from this plot is colored in

I want to get a lighter shade of a color...I have a lot of colored objects and want each one printed as a foreground against a slightly lighter background. I thought I could try something like changing the alpha channel by first converting it to rgb. But prior to trying that, I'm stuck with how to get the color after converting using col2rgb() to be interpreted again as a color, rather than

Hi I made heatmap of QTL based on Lod score. Where I have traits in columns and marker data (rows). I can not cluster both column and rows as I need the right order for marker data. Can someone suggest me better way of generating heatmaps especially the colour key I want to select to visualize the results which are more interesting to look at. > library(gplots) >

When I use grid.rect to print a multi-coloured grid, it is incredibly slow compared to a single colour grid, or even a two colour grid. I've set out some simplified examples below. This is something I run literally thousands of times a day, so I would greatly appreciate any hints on how I might improve the speed??? library(grid) pushViewport(viewport( width = unit(100,

Hi, I'm trying to draw a 2D plot using multiple tints of red. The (simplified) setup is the following: || year | x | y || My idea is that each year is plotted with a different tint of red. Older year (lightest) -> Later year (darkest). I've managed to plot this with different scales of grays simply by doing: palette(gray(length(years):0/length(years))) before the plot and for each

Dear R users, since R-2.4.0 I am not able any more to draw figures without transparency after drawing one figure with alphachannel set lower than 100%. For better unterstanding here a small example of my problem: ----------------------------------------------- pdf(paste("test_alpha_rgb.pdf",sep=""), version="1.4") plot(1:8, 1:8, type="n",

Hi all, I'm trying to convert a series of rgb codes into a color name. What is my easiest option? So far I'm stuck with just converting to hex using rgb() and I know R knows a number of colours() but a mapping of the two has failed me. Any help in this regard will be highly appreciated. Regards, George

Hello, I can't seem to add transparency to any color ramp I create using colorRampPalette(). Can someone tell me if it is possible to create transparent colour ramps? I am attempting to map shaded relief under elevation data. I know I can use the terrain.colors() with the alpha option, but I would prefer to create my own colour ramp using more vibrant colours. My most recent attempt at

Dear fellow R users, I would like to draw a "sunflowerplot" because I have data (decade by month) that plots multiple times on the same x-y co-ordinates. Further I would like to colour each of the points/sunflower leaves on the plot according to the group they belong to (i.e. which type of event each represents within that decade and month). I thought that this would be relatively

Hola, ¿hay alguna forma de colocar la leyenda de un gráfico sin que se superponga con las barras de mi gráfico? Os dejo mi ejemplo para que me entendáis: ## dado_1<-sample(1:6,1200,replace=T)dado_2<-sample(1:6,1200,replace=T)dado_3<-sample(1:6,1200,replace=T) dados<-matrix(c(table(dado_1),table(dado_2),table(dado_3)),6) barplot(t(dados),beside=TRUE,ylab="Frecuencias

Hi, I'd like to use a custom color sequence (black - low values, green - high values) in am image() plot. While I can specify colors (say a sequence of grays) to the col argument, the ordering is getting messed up. I have two questions: 1. How can I get a sequence of say 256 colors starting from black and ending in green? 2. How is this specified to image() such that it uses the colors in

Here is a proposal: At present when you specify a color with an integer it is taken as an index into a fixed table of 8 colors. 1=red, 2=green, 3=blue, 4=cyan, 5=magenta, 6=yellow, 7=white, 8=black [At least this is the intention, there may be bugs in the implementation]. Since I am looking at this anyway (to see if I can see the bug that Martin and Kurt have mentioned) I thought I might

Hi, I'd like to construct a somewhat unusual barplot. In "barplot" I use beside=F as I'd like to have stacked bars. The height of each bar is always the same. Information in my plot is coded in the color of the bar. I therefore need to be able so assign a different combination (or order) of colors to each individual stacked bar. In the example below, the combination of

Everyone, I'm working with scatter plots with different colored symbols (via lattice). I'm currently using these colors for points and lines: col1 <- c(rgb(1, 0, 0), rgb(0, 0, 1), rgb(0, 1, 0), rgb(0.55482458, 0.40350876, 0.04166666), rgb(0, 0, 0)) plot(seq(along = col1), pch = 16, col = col1, cex = 1.5) I'm also using these with transparency (alpha

Dear list members, I have been using filled.contour in order to plot EEG data. For the colors, I used a conventional ramp from blue to red (blue - green - yellow - red), and 100 color levels to make the plot looking smooth: (...) color.palette = colorRampPalette(c('blue','green', 'yellow','red'), space='rgb'), nlevels = 100 (...) My problem ist that

Full_Name: Hsiu-Khuern Tang Version: 1.8.0 OS: GNU/Linux (Debian unstable) Submission from: (NULL) (156.153.255.243) Hi, I use palette(rgb(red=..., green=..., blue=..., names=mycolors)) to define my own color palette. After doing this, the names `mycolors' are not stored in palette() anymore, so that palette() returns a mix of built-in color names and RGB values. Eg: > palette()