Re: [R] PCA on image data

2008-07-03 Thread Monica Pisica
e matrix you need to display your image. Hope this helps, Monica PS. I think prcomp() has the retx argument, not princomp() my answer pertains to princomp Message: 14 Date: Thu, 3 Jul 2008 02:15:43 -0700 (PDT) From: Bio7

Re: [R] PCA on image data

2008-07-03 Thread Bio7
Dear Jorge, i think it works. I have to investigate it further but have a visible result from your suggestion. Thank you very much for your help! With kind regards Marcel Austenfeld -- View this message in context: http://www.nabble.com/PCA-on-image-data-tp18255217p18259659.html Sent from the

Re: [R] PCA on image data

2008-07-03 Thread Jorge Ivan Velez
Dear Marcel, I'm sorry for the misunderstanding. I think what you really need are the scores values provided by PCA. See ?princomp for details. Here's an example: # PCA prin.comp=princomp(USArrests, cor = TRUE) summary(prin.comp) # What do you have in prin.comp? names(prin.comp) # Extracting th

Re: [R] PCA on image data

2008-07-03 Thread Bio7
Dear Jorge, As i've already written the princomp method works for me. But i'm interested to produce from the results a matrix which i can visualize (e.g the first pc) in an image application and which is then the source for a clustering algorithm. The background is that i've an application which

Re: [R] PCA on image data

2008-07-03 Thread Jorge Ivan Velez
Dear Marcel, See ?princomp. HTH, Jorge On Thu, Jul 3, 2008 at 5:15 AM, Bio7 <[EMAIL PROTECTED]> wrote: > > Dear R users, > > i would like to apply a PCA on image data for data reduction. > The image data is available as three matrices for the > RGB values. At the moment i use > > x <- data.fra

[R] PCA on image data

2008-07-03 Thread Bio7
Dear R users, i would like to apply a PCA on image data for data reduction. The image data is available as three matrices for the RGB values. At the moment i use x <- data.frame(R,G,B)#convert image data to data frame pca<-princomp(x,retx = TRUE) This is working so far. >From this results th