[GRASS-user] new addon: v.faultdirections

[Moritz Lennert]

Hi Rich,

On 04/11/16 13:31, Rich Shepard wrote:
> On Fri, 4 Nov 2016, Moritz Lennert wrote:
>
>> As a result of some work with a student, I've just committed a small and
>> very simple addon that takes azimuths of lines from the attribute table
>> and draws a polar bar frequency plot in order to be able to visually
>> determine the dominant direction(s).
>>
>> As this is generally used for geological faults, I called it
>> v.faultdirections.
>
>    Will this create wind rose diagrams, too? Air pollution modeling depends
> on those.

Well, in its current form it takes a vector map with lines and the 
azimuth of these lines in the attribute table. It then creates a 
frequency plot of the lines according to direction as a polar bar plot. 
Nothing more. So, if you have, e.g., each day's wind of the year as a 
line in a vector map, you could use this to create a frequency plot of 
the winds, but there is currently no way to color bar in a 
differentiated symbology for something like speed.

If you have a list of winds with their direction and speed, you'd 
probably be better off directly using matplotlib. You can look at the 
source code of v.faultdirections for inspiration, if needed.

But maybe this module could be improved and complexified to suit more 
uses...

Moritz