similar to: RGB function

Hi all, In response to a previous post about plotting a numeric square matrix as a colored matrix, I was referred to both image and the color2D.matplot function in the plotrix package. Both have worked for me thanks!! However I need to plot my data in a log transformed color scale. Is this possible? I will be happy to explain further, but basically I need to do this because there are large

Hello All, I have a device that spews out experimental data as a series of text files each of which contains one column with several rows of numeric data. My problem is that for each trial it gives me one text file (and I run between 30 to 50 trials at a time) and I would ideally like to merge all these text files into one large data frame with each column representing a single trial. It is not

Hi all, I have a x, y matrix of numbers (usually ranging from 0 to 40). I need to group these numbers and assign a color to each group (for example 0 to 15 - Blue, 16-30- Yellow, and 31-40- Red). Then I need to draw a rectangular matrix which contains X x Y boxes and each box has the corresponding value from the input matrix and is also colored according to which group (i.e red, yellow,

Hi, I have two data frames each with 5 columns and different number of rows. some of the row names in one data frame are the same as the row names in the other. I want to be able to merge the two data frames to get a new data frame in which the duplicated row names are only shown once with the data for the rest of the columns used from the first data frame. Essentially, I want to make a union

Hi all, I have a matrix with each column containing a large number of integers (0 and above). in each column beyond a certain row (say row 120 in column 1, row 134 in column 2, 142 in column 3...) there are only 0's. I want to find, for each column the row number of the last row which contains a positive integer beyond which there are 10 or more 0's. so in the following example (single

Based on reading 'rgb' documentation, I would have thought the following would have produced identical results. Can someone explain how to make this happen? I need to be able to specify an array of rgb values for the 'col' parameter. colnames.col <- c("black", "red", "blue", "green") colnames.rgb <- apply(as.matrix(colnames.col), 1,

A quick question: Is there anywhere a listing of the RGB components of the named colours listed by colors()? For example, where would I find the RGB for "orange1" or "salmon"? When I look at an EPS file from R where I have used these colours, it seems that for: "salmon": 0.9804 0.5020 0.4471 rgb "orange1": 1 0.6471 0 rgb However, this is a tedious way

Hi All, In function "rgb", alpha parameter is supposed to set the transparency value. But in my following two examples, it didn't work: plot(1,col = rgb(1,0,0,alpha =0.8)) # as long as alpha < 1, there is no point in the plot. plot(1,col = rgb(0,0,255, alpha=254, maxColorValue=255)) # as long as alpha < 255, there is no point in the plot. Do I use it in the right way? Any

Greetings, After pouring over the documentation for the 'colorspace' package, I have not been able to figure out how the plot() method converts colorspace coordinates to RGB values for display on the screen. I am convert between colorspaces with the various as() methods... but cannot seem to find a way to extract RGB (i.e. for displaying on a computer screen) triplets from color space

Hi, I m working on latex and R and i need to dynamically generate colors. r<-paste("rgb(1.000,",0,",",0,")",sep="") # i m generating dynamically by paste command cars <- c(1, 3, 6, 4, 9) plot(cars, type="o", col=r) *Error in plot.xy(xy, type, ...) : invalid colour name 'rgb(1.000,0,0)'* How to fix this

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 all, how can I convert a RGB (24 or 32) image I'm getting from a webcam for example to YUV to compress it with theora, decompress it and convert it back to RGB to draw it? Any suggestions? Best regards, Florian (Stuttgart, GERMANY)

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

Hi, I coded some routines for YCbCr <-> RGB conversion, both using floating point numbers and using integer arithmetics, code is attached. Let's say I want to convert from RGB to YCbCr and back. First the integer arithmetics: In [1]: from colors import * In [2]: a = [255, 0, 255] In [3]: RGB2YCbCr(a) Out[3]: (107, 202, 222) In [4]: YCbCr2RGB(RGB2YCbCr(a)) Out[4]: array([255, 1,

I've spent the weekend or so trying to get my head around Theora and I'm just not having any luck. First of all, I really don't have any interest in immersing myself in video encoding--I just have one simple thing I'd like to do--so I haven't spent any time reading about the theory or specs or anything like that. I'm attempting to write a "render-to-theora"

Hello all, I'd like to convert the theora yuv_buffer to RGB that I can render onto a texture. Googling around, there are a tone of different formulae to do so. There is this (with lots of corrections and amendments further down the page): http://www.fourcc.org/fccyvrgb.php <http://www.fourcc.org/fccyvrgb.php> and there is the MSDN stuff that says you need to convert 4:2:0 and

Hello, i'm sorry for my English is not good. I need help with convert yuv_buffer data (YCbCr) to RGB without SDL. I write: BYTE *frame=new BYTE[YUV_BUFFER.y_height*YUV_BUFFER.y_width*4]; for(int cc=0; cc<YUV_BUFFER.y_height*YUV_BUFFER.y_width; cc++) { frame[cc*4+0]=YUV_BUFFER.y[cc]+1.371*(YUV_BUFFER.v[cc]-128);

Hello list, When I convert an yuv pixel into rgb using the recipies in http://www.fourcc.org/fccyvrgb.php I get an accurate color conversion but the contrast seems to be decreased. If i write, e.g., the pixel directly into an sdl yuv_overlay, I get a well-contrasted frame, however, if I convert the pixel to rgb and call SDL_MapRGB, I get a contrast-decreased frame. Thanks, Ribamar

Hello all, I'm now using image() to show image data (in my case dumps of SOM weights) but would like to show RGB colour data, not just single "z" colour values. I've currently been using seq() to skip 4 values, so I can show the R, G or B channels separately as "z". But is there a way I can show all three channels simultaneously as a proper colour image? Thanks, B.

I've writen this function (imagenrgb) to display a (m,n,3) array as a RGB image with ngris^3 colors and,optionally, stretching. If option ver=F, it does not display but saves a pseudocolor version of the image as a list (so that subsequent displays are faster). I'd appreciate feedback and improvements and hope that it's useful for others. Example of use: > dim(imatest) [1] 100