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5

Here is a quick worked example of setting the GRASS environment, reading an on-disk raster, calculating a focal mean (using r.neighbors) and reading the results back into R. Hopefully this will get you started. if (!require(rgrass7)) stop("rgrass7 PACKAGE MISSING") setwd("D:/TMP") # Working directory # Set on-disk raster variable rname <- ...


2

You should check out SFCGAL, which is a C++ wrapper library around CGAL with the aim of supporting ISO 19107:2013 and OGC Simple Features Access 1.2 for 3D operations. You can use it from a specialised version of PostGIS, here are the functions for PostGIS 2.1. Also, check out the existing functions that matches \df ST_3D*, which doesn't require SFCGAL. ...


2

GRASS 7 is not compatible with QGIS 2.8. You can follow the development of the new GRASS plugin on http://www.gissula.eu/qgis-grass-plugin-crowdfunding/progress.html. For 2.8, you will need to install GRASS 6.x.


2

r.bioclim (I suppose, because r.bioclimatic don't exist), is an GRASS GIS 7 addon If you want to create or modify an algorithm, read the file ../processing/algs/grass7/grass7.txt that begins with "A short guide for creating and editing GRASS GIS 7 algorithms" But, how do these commands work ? to use the GRASS7 commands in processing,you need to first ...


2

There is no function, but you can use the modulus operator, which is "%" in GRASS (as in many other languages), e.g. 8%5=3 for a pixel-by-pixel computation, simply use the layer names layerOne%layerTwo


2

The DOS methods are for atmospheric correction only, not radiometric correction. The i.*.toar modules allow you to combine in one step radiometric correction with some additional DOS atmospheric correction method. The input to the i.*.toar modules is the original DN values. The default to i.*.toar is "uncorrected", so normally you would use i.*.toar to get ...


1

This might do it: r.mapcalc "distances_with_negatives = if(isnull(B), -1.0*A, A)"


1

Adding a .tif extension to the file name solved the problem.


1

I think is better to use r.series. You have 4 files with different values (as I can see). You have to choose the function according to what you want to have. I suppose you want the files with the value 10 "up" the others from "behind". Perhaps you can use the r.series twice. First for the DEM files and then for the roads using the maximum function. For the ...


1

Thank you very much for your responses! Eventually, is very very easy to work with GRASS GIS through R. After you have created in GRASS the location and mapset in which you wish to work, you can type in the GRASS shell: "rstudio &" "&" Helps for working simultaneously in both GRASS GIS and R. Otherwise, the GRASS shell would switch to R. And that is ...


1

It looks like, from the docs: http://grass.osgeo.org/grass70/manuals/addons/r.to.vect.lines.html that there is a skip parameter. The default is 10 so perhaps if you reduce it you will get more points. It looks like there's a smoothing function in grass too: http://grass.osgeo.org/grass64/manuals/v.generalize.html with tutorial: ...



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