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I want to perform a view shed analysis in QGIS using GRASS 7 r.viewshed.

When I double click on r.viewshed in GRASS GIS 7 commands in the processing toolbox of QGIS I get the following message:

Missing dependency.This algorithm cannot be run :-( This algorithm requires GRASS GIS 7 to be run. Unfortunately, it seems that GRASS GIS 7 is not installed in your system, or it is not correctly configured to be used from QGIS Click here to know more about how to install and configure GRASS GIS 7 to be used with QGIS

GRASS commands seem to work such as r.los but the GRASS 7 commands don't.

I am using a MAC OS X Mavericks with the latest version of QGIS 2.4.0 Chugiak.

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GRASS 7 is still in a beta release stage. The Kyngchaos.com package is a stable release of QGIS, which does not yet include GRASS 7 internally. You can get a copy using the Homebrew package manager and the OSGeo4Mac tap:

  1. Install Xcode, Xcode Command Line Tools and Homebrew

  2. Then, in Terminal run: brew install osgeo/osgeo4mac/grass-70 (if your HOMEBREW_PREFIX is the default /usr/local then a pre-built binary will be installed on Mavericks)

  3. Set in QGIS, in Processing->Options menu's dialog: Providers->GRASS GIS 7 commands->GRASS 7 folder to (your HOMEBREW_PREFIX path)/opt/grass-70/grass-base

Occasionally, you may have to open and close the Processing Options dialog to get Processing to remember settings after a relaunch of QGIS, at least on Mac (current bug).

  • Thanks for your answer, I have followed all the steps but when I try to open any GRASS 7 command, QGIS crashes and I have to force quit the application. Do you know how I can fix this? – lilmawi Aug 12 '14 at 21:33
  • Hmmm. If it is crashing QGIS, you would be getting the crash report dialog. If you have to force quit the app, then something is probably spinning out of control. More information would be helpful. I will try to replicate the issue here. – dakcarto Aug 13 '14 at 21:24
  • Sorry, I can't replicate the issue here. You may want to report it on the QGIS issue tracker. – dakcarto Aug 13 '14 at 21:47
  • Thanks for your response. I wish I could provide more info but after I click a command the rainbow wheel starts spinning and it doesn't stop. Maybe I should try uninstalling and reinstalling everything? – lilmawi Aug 13 '14 at 21:52
  • I am able to select 'execute as batch process' on r.viewshed. Can I execute a single view shed analysis with this command? Does this command work in the same way as the normal r.viewshed? – lilmawi Aug 17 '14 at 8:02

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