similar to: converting a vector of bytes to a PNG/JPEG image

Hello, I have a problem that I think can be solved in R but I'm not sure how to tie things together. I have a digital image of a crystal growth in 2 dimensions. And my aim is to calculate the fractal dimension of the crystal. I was planning to use the box counting method. So I need to read in the image in R (for which I can use the pixmap or rimage packages) and then draw a grid over at a

Dear R-help I want to display an image file in a new plot frame. SVG is my preferred format, but I can also consider PNG, GIF, JPEG, TIFF, and PPM (from ImageMagick). By way of background (although not material to this posting), the image file is generated by a call to 'dot' (part of the 'Graphviz' suite) after the required .dot file has been produced using hand-crafted R code.

Hi there I'm looking for a function to read PNG-bitmap-images from a file into R. I only found: - the pixmap-package which cannot import png or similar formats - the rimage-package which can only import lossy jpeg-images (the convertion from png to jpeg modifies the data!) Is there any possibility to read PNG-files? Thanks for any help Dominic Sydler

I'm interested in digitizing some scanned time series, and looking for a solution that is easy and flexible. I thought I might be able to use R's locator() if I could get the image into a device. I noticed that there are some packages like (rimage), but it (a) doesn't seem to be available for the Windows version and forces me to upgrade a bunch of libraries for my linux system. It

Hi, I have a plot and I would like to overlay a PNG image over it. I'm using the rasterImage function to do this, but the problem I'm facing is working out the coordinates of the upper right corner of the final image in user coordinates. That is I can place the image so the lower left is located at the bottom of the y-axis and the left end of the x-axis. Since my image is say 100px x

Hi Helpers, Does anyone know how to read jpeg, bmp or png files into R? I have some photos of brain scans and I want to quantify some aspects of their size. I might be able to do this with the 'locator' function, if I could figure out how to read the files in and make them into an image that I can display on the R Windows device. I have experimented with readBin, using a simple

Hi, is there a way to plot distribution curves (say normal or chi sq etc) from within R? For example I looked up the *chisq family of functions but I'm not sure as to how I would use them to generate a plot of the chi sq distribution (for arbitrary d.o.f). Thanks, ------------------------------------------------------------------- Rajarshi Guha <rajarshi at presidency.com>

Can someone advise me what the most sensible way is to read jpeg images? For our work with image analysis and eye-tracking we have been using the rimage package, on both Macs and Windows PCs. But while setting up a new Windows machine yesterday, I see that rimage is regarded as orphaned, and no Windows binary is available. I eventually found an old zip file for the package, so I

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I'm a new user of R and have managed to make a plot of a histogram. Is there any way I set the title and axes labels and then save the plot as an image (png/gif)? Thanks - -- - ------------------------------------------------------------------- Rajarshi Guha <rajarshi at presidency.com> <http://jijo.cjb.net> GPG

Hi, this question is probably very obvious but I just cant see where I might be going wrong. I'm using the lm() function to generate a linear model and then make predictions using a different set of data. To generate the model I do (tdata & pdata are matrices of observations and parameters, tdepv, pdepv are response vectors) x <- as.data.frame(tdata) x$tdepv <- tdepv

Hi, I'm writing code to generate a plot, in which I draw a series of rectangles. So my code is of the form plot.new() plot.window( ... ) draw rectangle draw rectangle ... Is there a way for me to insert a PNG or PDF graphic at a specific position in the plot (ideally in plot coordinates)? I realize that this might probably be better done in a separate image editor, but if it could

Hi, I have 3 lists, x, y, z and I'd like to perform a calculation over all the lists simultaneously. If it were a single list I could use lapply, but for more than one list I'm using a for loop. Is there an idiom that would let me use something like lapply, but the function specified to lappy would have access to an element from each list? (In Python, I would have used for a,b,c in

Hi, is the following possible - in a given session I make a lot of objects and save when exiting. Usually I note down seperately what each object is about. Is it possible to attach data to any object which would essentially be a short note explaining the meaning of it? Thanks, ------------------------------------------------------------------- Rajarshi Guha <rxg218 at psu.edu>

Hi, I'me trying to write a function that will shuffle a vector. At the moment I'm baically making a vector of randomized indices and then making a new vector from the original one using these random indices. However, is there an alternative (more elegant) method to do this? I tried help.search('shuffle') but it does'nt return anything relevant. Thanks,

Hi, I have a data.frame that has a categorical variable, for which I would like to look at the distribution of levels of this variable, based on a grouping of two other variables. As an example: x <- data.frame(obs=sample(c('low', 'high'),100, replace=TRUE), grp1=sample(1:10, 100, replace=TRUE), grp2=runif(100)) cut.grp1 <- cut(x$grp1, 3) cut.grp2 <- cut(x$grp2, 3)

Hi, I'm plotting 4 graphs on one page (2x2 matrix) but I cant seem to get the title for the whole page right. I'm doing: op <- par(mfrow = c(2,2), pty="s") hist(var$V2, breaks="FD",main="Euclidean Metric", xlab="Sum of 3NN ... hist(var$V2, breaks="FD",main="Manhattan Metric", xlab="Sum of 3NN ... hist(var$V2,

Hi, I have a data.frame with columns named X, D1, D2, D3 I know I can get a single plot with 3 curves by doing xyplot(D1 + D2 + D3 ~ X, data) but in some cases I might have columns D1 ... D10. Is there a way to plot all 10 columns without having to specify each individual term? (By analogy with formulae in lm, I thought, xyplot(. ~ X, data) would work, but it didn't) Thanks, --

Hi, I'm using the ks.test() on two vectors. I looked up the reference and also coded up a version of the two sample Smirnov test. My question is that how can I decide from the output of R that the two vectors x & y come from the same distribution? Am I correct in assuming that smaller D values indicate that they come from the same distribution? In addition how can I use the p value that

Hi, I have some data which I was plotting using image(). I wanted to add a vertical color key to the plot and I found that heatmap.2 in gplots does let me add a color key. However, I was thinking of a vertical bar with the color range rather than the style that gplots provides. Is there any package (or code snippet) that would let me add a vertical color key to an image() or heatmap

Does someone here know of a way to display images in R that isn't slow? Here are the things I've tried so far: library(rimage) i<-read.jpeg('foo.jpg') plot(i) # very slow library(pixmap) i <- read.pnm('foo.pnm') plot(i) # also slow chans <- getChannels(i) image(chans[,,1]) # this is slow too I also tried using library(cairoDevice) but it only makes everything