Thank you for the information- I'll try that approach out. The new version of ENVI (4.5) is optimized to work with ArcGIS, so there may be a way to pass spectra from ENVI to ArcGIS and then on to R if I can't set up a direct ENVI/IDL to R connection.
I agree with you that R isn't for image processing (I certainly enjoyed the two-three minute wait I had to endure to show a single band ENVI image in R, something which would have been rendered instantly in ENVI)- what we're interested in is using R for statistical capabilities currently not available in either ENVI or IDL. Thanks for all your help, Guy On Wed, Jul 30, 2008 at 4:49 AM, Roger Bivand <[EMAIL PROTECTED]> wrote: > On Tue, 29 Jul 2008, Guy Serbin wrote: > >> My machine currently has 4 GB on it, but a lot of that's getting eaten >> by video memory and the other programs I have in memory. Also, some >> of my image cubes are 12 GB in size, so I'd need to find a workaround >> anyways. However, since what my colleagues and I are interested in >> are pixel-by-pixel spectral analyses, I assume the best approach would >> be to pass the spectra either from ENVI/IDL (for which there is no >> frontend, but I have logged a request with ITT Visual Solutions to >> develop one) or conversely from ArcGIS (which can read ENVI data with >> the ENVI Reader) into R for analysis. >> >> Are you aware of ways to send arrays back and forth between R and ArcGIS? > > You can use R as a back-end compute engine through (D)COM, see: > > http://cran.r-project.org/contrib/extra/dcom/ > > and note the scripting sample for Python. Regular (D)COM does arrays easily > in VBA, going through usually Python means an extra copy, but may be more > convenient. One needs to watch error trapping and what the different systems > do with Inf, NaN, and NA values. I usually start from Python in front, and > both Arc and R via (D)COM, but the Duke University MGET site has lots of > code examples for interfacing R and Arc in different configurations: > > http://code.env.duke.edu/projects/mget > > MGET is under active development. > > Roger > >> >> Guy >> >> On Tue, Jul 29, 2008 at 4:24 PM, Roger Bivand <[EMAIL PROTECTED]> wrote: >>> >>> On Tue, 29 Jul 2008, Guy Serbin wrote: >>> >>>> Thank you all for the help- I successfully read an image into R using >>>> these methods. >>>> >>>> I did, however, encounter some problems when loading a hyperspectral >>>> image cube into R as it was unable to allocate the 2.9 GB of volatile >>>> memory that it needed. >>> >>> Buy more memory, 64-bit Linux works fine. Seriously, R is for statistics, >>> so >>> its memory management is designed for samples, even though very large >>> samples can be handled when used appropriately. If your data are in a >>> GeoTiff, you can read them by band using functions in the rgdal package, >>> or >>> equally well many bands in a window or tile of a larger scene. Note that >>> ArcGIS uses GDAL too for handling some raster formats. Using R does mean >>> thinking through your work flow. >>> >>> Roger >>> >>>> >>>> Is there a way to improve memory management by R, so that it only >>>> reads in the data when actually needed for processing, e.g., only read >>>> in the bands I need, or conversely read in spectra on a per-pixel >>>> basis? >>>> >>>> Guy >>>> >>>> On Tue, Jul 29, 2008 at 4:05 PM, PUJAN RAJ REGMI >>>> <[EMAIL PROTECTED]> wrote: >>>>> >>>>> This might help to mange the orientation of image: >>>>> >>>>> # To read ENVI format >>>>> cir.image<-("YOUR_ENVI_FILE") >>>>> >>>>> CIR.envi<-read.ENVI(cir.image,headerfile=paste(cir.image,".hdr",sep="")) >>>>> # To Show image >>>>> CIR.envi.band1<-CIR.envi[,,1] >>>>> CIR.envi.band1.s<-CIR.envi.band1[order(nrow(CIR.envi.band1):1),] >>>>> CIR.envi.band1.t<-t(CIR.envi.band1.s) >>>>> image(CIR.envi.band1.t,main="") >>>>> mtext("Raw Matrix ENVI Image for Band1", side=3,line=2, >>>>> font=3,cex=1.25) >>>>> >>>>> Pujan >>>>> ________________________________ >>>>>> >>>>>> From: [EMAIL PROTECTED] >>>>>> To: [EMAIL PROTECTED]; R-sig-Geo@stat.math.ethz.ch >>>>>> Date: Tue, 29 Jul 2008 14:24:04 -0400 >>>>>> Subject: Re: [R-sig-Geo] ENVI data and R >>>>>> >>>>>> This code might help: >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> ## Read in envi file >>>>>> cir.image <- "C:/YOUR_ENVI_FILE" >>>>>> CIR.envi = read.ENVI(cir.image, headerfile=paste(cir.image,".hdr", >>>>>> sep="")) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> ## Show image >>>>>> CIR.envi.band1 <- CIR.envi[,,1] >>>>>> image(CIR.envi.band1, main="") >>>>>> mtext("Raw Matrix ENVI Image for Band 1", side=3,line = 2, font=3, >>>>>> cex=1.25) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> >>>>>> >>>>>> >>>>>> ############################################################################ >>>>>> #### >>>>>> >>>>>> Andrew Niccolai >>>>>> Doctoral Candidate >>>>>> Yale School of Forestry >>>>>> >>>>>> >>>>>> >>>>>> -----Original Message----- >>>>>> From: [EMAIL PROTECTED] >>>>>> [mailto:[EMAIL PROTECTED] On Behalf Of Guy Serbin >>>>>> Sent: Tuesday, July 29, 2008 12:55 PM >>>>>> To: R-sig-Geo@stat.math.ethz.ch >>>>>> Subject: [R-sig-Geo] ENVI data and R >>>>>> >>>>>> Hi, >>>>>> >>>>>> I was wondering if anyone knows how to either call up R functions from >>>>>> within IDL, or conversely read ENVI image data into R. If you have >>>>>> any advice I'd greatly appreciate it. >>>>>> >>>>>> Thanks, >>>>>> Guy Serbin >>>>>> >>>>>> -- >>>>>> Guy Serbin, Ph.D. >>>>>> Research Soil Scientist >>>>>> Hydrology and Remote Sensing Lab >>>>>> Bldg 007 Rm 104 BARC-West >>>>>> 10300 Baltimore Blvd >>>>>> Beltsville, MD 20705-2350 USA >>>>>> +1(301)504-5250 [EMAIL PROTECTED] >>>>>> >>>>>> _______________________________________________ >>>>>> R-sig-Geo mailing list >>>>>> R-sig-Geo@stat.math.ethz.ch >>>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >>>>>> >>>>>> _______________________________________________ >>>>>> R-sig-Geo mailing list >>>>>> R-sig-Geo@stat.math.ethz.ch >>>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo >>>>> >>>>> ________________________________ >>>>> Stay in touch when you're away with Windows Live Messenger. IM anytime >>>>> you're online. >>>> >>>> >>>> >>>> >>> >>> -- >>> Roger Bivand >>> Economic Geography Section, Department of Economics, Norwegian School of >>> Economics and Business Administration, Helleveien 30, N-5045 Bergen, >>> Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 >>> e-mail: [EMAIL PROTECTED] >>> >>> >> >> >> >> > > -- > Roger Bivand > Economic Geography Section, Department of Economics, Norwegian School of > Economics and Business Administration, Helleveien 30, N-5045 Bergen, > Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 > e-mail: [EMAIL PROTECTED] > > -- Guy Serbin, Ph.D. Research Soil Scientist Hydrology and Remote Sensing Lab Bldg 007 Rm 104 BARC-West 10300 Baltimore Blvd Beltsville, MD 20705-2350 USA +1(301)504-5250 [EMAIL PROTECTED] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo