With the addition of "rasterfile" and "vectorfile" for me personally there are no more wishes open. I think it is absolutely required as it makes every individual solution possible. The same for the saving of the files.
Thanks again! 2013/2/22 Victor Olaya <[email protected]> > If you are using the latest version, you should have an example R script > called Advanced raster histogram, with the following code > > ##Classification=group > > ##Layer = raster|R.raster > > ##no_data_value = number 0 > > ##showplots > > Layer <- raster(Layer, 1) > > NAvalue(Layer) = no_data_value > > hist(as.matrix(Layer), breaks=100, xlab = basename(filename(Layer))) > > > It uses the raster package > > > What do you think of this solution? Leaving the current types "raster" and > "vector", which create the object in R, and then two additional ones > "rasterfile" and "vectorfile", that create the same interface but skip the > process of creating the obejct and pass the filename string to R. That woul > be more flexible, and not to complex. > > > For the latest docs, have a look at the QGIS doc repo: > http://github.com/qgis/QGIS-Documentation/tree/master/source/docs/user_manual/sextante > > > Regards > > Victor > > > > 2013/2/22 Matteo Mattiuzzi <[email protected]> > >> Sounds great! >> I could imagine to have a default method (for raster/vector) to >> facilitate the transfer of the data into R. I think rgdal is a quite >> low-level package that is also used by the raster package. I think that at >> least for raster data the package raster is the most advanced and most >> user-friendly package at all and also the most diffused in the community. >> >> to load a raster-file it has 3 function: >> raster # used for single layer raster data >> stack # used for multiple single- or multi-layer files loaded as 1 >> multilayer file (requires identical extent, proj and resolution for all >> files), comparable with a BSQ file with separate sources >> brick # used for a multi-layer image (tipically BIP, BIL) >> # the problem could be here that the user has to know in advanced which >> one to use. In most of the cases its fairly simple, or the function stack() >> could handle every input, but I'm not sure it it is the best solution. >> >> to write a raster file: >> writeRaster >> Normally the raster package writes everything to a tmp folder, >> writeRaster is basically the function to move the file from the tmp to a >> definitive location handing datatype, filename, driver etc. >> >> For reading and writing vector data it presents some limited facilities, >> but very simple to use, could also be suitable as a default method, and if >> required it will be easy to amplify its functionality. >> shapefile # uses readOGR/writeOGR and can handle only ESRI shapefiles.... >> >> From my point of view I could imagine to have such default, but I think >> it has to be easy to modify (as you wrote me!). I will try to mobilitate >> some R-SIG-GEO members for this discussion. >> I have tried: >> ##myraster=raster|R.Raster >> and also >> ##myraster=raster|R.raster >> but I was not successful. I'm using the developer version from git but I >> don't know how to get to the documentation... Actually every time a script >> has some non-conform values it disappears from the list... >> >> Thanks! >> Matteo >> >> >> >> >> >> >> 2013/2/22 Victor Olaya <[email protected]> >> >>> Matteo >>> >>> Thanks for your ideas >>> >>> you can tell SEXTANTE to use the raster package by using >>> >>> ##myraster=raster|R.Raster >>> >>> instead of >>> >>> ##myraster=raster >>> >>> This is already documented, but only in the github version of the >>> documentation, as it is something that is implemented only in the >>> development versino of SEXTANTE. >>> >>> Anyway, your proposal seems interesting. I tried to save all the >>> possible effort from users developing R algorithms in SEXTANTE, but it's >>> true that you will have more flexibility by just getting the filename. >>> >>> Honestly, I am not an R expert, so I will implement whatever you the R >>> users think is best. My goal is to make it easier for anyonen with a good >>> knowledge of R to adapt their algorithms to SEXTANTE and be able to call >>> them from QGIS. I am opne to all kind off suggestions, since, as I said, I >>> am not an R user and my knowledge of R is very limited. >>> >>> Let's discuss this here in the list.. Hopefully other people using R and >>> SEXTANTE will give their opinion and we can decide what to do >>> >>> Many thanks again for your help >>> >>> Victor >>> >>> >>> >>> >>> 2013/2/22 Matteo Mattiuzzi <[email protected]> >>> >>>> Dear list, >>>> >>>> I have now tested the possibilities to integrate R Processing in Q-GIS. >>>> I think it closes the huge gap in R of interactive visualization and also >>>> gives the possibility to use R-functionality to non-R people! >>>> >>>> I saw that a raster/vector file is loaded through rgdal and there is no >>>> possibility to do it in the own way, such as the almost standard 'raster' >>>> package that handles also out of RAM data! >>>> In order to maintain the flexibility of R I think that arguments should >>>> be passed as they are (path+file) and everybody would be free to benefit >>>> from the entire R repository of functions. >>>> Thanks Matteo >>>> >>>> here an example for extracting and plotting pixels based on vector, >>>> point or polygon shp file: >>>> >>>> ##[MyScr]=group >>>> ##vector=vector >>>> ##raster=raster >>>> library(raster) >>>> >>>> s <- shapefile(vector) % high level function from raster package, the >>>> argument should be only the file path+ name >>>> r <- brick(raster) % high level function from raster package, the >>>> argument should be only the file path+ name >>>> >>>> v <- extract(r,s) >>>> ##showplots >>>> for(u in seq_along(v)) >>>> { >>>> val <- v[[u]] >>>> if(u>1) X11() >>>> >>>> >>>> plot(x=1:ncol(val),ylim=c(min(val),max(val)),type="n",main=paste("Extraction >>>> line",u),xlab="Band",ylab="Spectral") >>>> >>>> for(i in 1:nrow(val)) >>>> { >>>> lines(val[i,],col=i) >>>> } >>>> } >>>> >>>> ############################ >>>> LINUX Ubuntu 12.10 >>>> QGIS version1.9.0-MasterQGIS code revision 2a2465eCompiled against Qt >>>> 4.8.1Running against Qt4.8.1Compiled against GDAL/OGR1.9.2Running >>>> against GDAL/OGR1.9.2 GEOS Version3.3.3PostgreSQL Client >>>> Version9.1.8SpatiaLite >>>> Version3.1.0-RC2QWT Version5.2.2PROJ.4 Version480QScintilla2 Version This >>>> copy of QGIS writes debugging output. >>>> >>>> R version 2.15.2 (2012-10-26) -- "Trick or Treat" >>>> >>>> >>>> _______________________________________________ >>>> Qgis-developer mailing list >>>> [email protected] >>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer >>>> >>>> >>> >> >
_______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
