[GRASS-user] i.gensig - multiple signatures into a single file for i.maxlik

[Moritz Lennert]

Hi Paul,

Please keep discussions on the list.

Le Fri, 8 Jun 2018 10:33:56 +0100,
Paul Shapley <p.shapley at gmail.com> a écrit :

> Hi Moritz,
> 
> Thank you for your help. I am trying to get 5 signatures but the layer
> manager is out of action whilst i create the signatures in the 'Class
> Manager'. 

What do you mean by "out of action" ? And why do you need the layer
manager while using the class manager (we are speaking about
g.gui.iclass [1], here, or ?) ? You can directly create different
classes in one run of this tool. You can save your training areas as a
one single vector map containing all areas of all classes and/or
create the signature file (containing all classes). Check out the video
tutorial linked at [2].

> I need to move the map window between each signature. If i
> could do them individually i can combine the signatures into one file
> later before using 'i.maxlik'.

If you have different classes in different vector maps, you can combine
them using v.patch, rasterize the result using v.to.rast (or possibly
v.to.rast on each and then r.patch) and use then use the resulting
raster map as input for i.gensig. It will automatically create the
signature file combining all classes.

Moritz

[1] https://grass.osgeo.org/grass74/manuals/wxGUI.iclass.html
[2] http://grasswiki.osgeo.org/wiki/WxGUI_Supervised_Classification_Tool