[GRASS-dev] [GRASS GIS] #2464: g.gui.iclass: show output of signature creation

#2464: g.gui.iclass: show output of signature creation
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Reporter: mlennert | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.1.0
Component: wxGUI | Version: svn-releasebranch70
Keywords: g.gui.iclass signature | Platform: Unspecified
      Cpu: Unspecified |
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Sometimes, when training areas are not good enough, trying to create a
maxlik signature file provokes messages such as "Signature X not
invertible". Then trying to run i.maxlik on that signature file, you get
the message "Unable to read signature file" (why that has to be so is a
different question). So when you see the "not invertible" message, you
know that you have to improve the training areas (or use a different image
group).

However when you use g.gui.iclass, you never see the output of i.gensig
and so you just go on and then get the i.maxlik message without
understanging why. g.gui.iclass should allow the user to see the i.gensig
output.

Moritz

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2464&gt;
GRASS GIS <http://grass.osgeo.org>

#2464: g.gui.iclass: show output of signature creation
------------------------------------+---------------------------------------
Reporter: mlennert | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.1.0
Component: wxGUI | Version: svn-releasebranch70
Keywords: g.gui.iclass signature | Platform: Unspecified
      Cpu: Unspecified |
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Comment(by wenzeslaus):

As far as I know, `g.gui.iclass` is not using `i.gensig`. There is a
custom mechanism of creating the signature files taken from `i.class`.

`g.gui.iclass` access this functionality using ctypes. The functionality
was moved the the library. It is not really good but it was the fastest
way to implement it without need of a new module, format or change in
functionality comparing to `i.class`. See also
wiki:wxGUIDevelopment/wxIClass.

There is probably some other way, how to address your issue.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/2464#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>

#2464: g.gui.iclass: show output of signature creation
------------------------------------+---------------------------------------
Reporter: mlennert | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.1.0
Component: wxGUI | Version: svn-releasebranch70
Keywords: g.gui.iclass signature | Platform: Unspecified
      Cpu: Unspecified |
------------------------------------+---------------------------------------

Comment(by mlennert):

Replying to [comment:1 wenzeslaus]:
> As far as I know, `g.gui.iclass` is not using `i.gensig`. There is a
custom mechanism of creating the signature files taken from `i.class`.
>
> `g.gui.iclass` access this functionality using ctypes. The functionality
was moved the the library. It is not really good but it was the fastest
way to implement it without need of a new module, format or change in
functionality comparing to `i.class`. See also
wiki:wxGUIDevelopment/wxIClass.
>
> There is probably some other way, how to address your issue.

I don't have the time to dive into the code, now, but is there no
message/error handling in the i.class code concerning the signature
creation (and notably the "Signature X not invertible" message) ?

Moritz

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/2464#comment:2&gt;
GRASS GIS <http://grass.osgeo.org>