[GRASS-user] v.generalize and external boundaries

[Daniel McInerney]

Hi List,

I'm using v.generalize in a script (excerpt included below) to smooth
the boundaries of a polygon vector dataset. In the attached example
(input_vector.png), I would like to *only* generalize the internal lines
(blue), and leave the external boundary (green line) unchanged. I
thought that the flag, '-l' might provide this functionality, but
unfortunately the resulting external boundary is changed significantly
(attached vgeneralize_output.png).

Is this functionality available in v.generalize or is there another way
that this could be achieved in GRASS?

Thanks in advance.

Best regards,
Daniel.

##run generalisation (step: 1 - douglas)
gscript.run_command('v.generalize', flags='l', overwrite=True,
input='segments', output='segments_douglas', method='douglas', threshold=1)

##run generalisation (step: 2 - sliding average)
gscript.run_command('v.generalize', flags='l', overwrite=True,
input='segments_douglas', output='segments_douglas_slide',
method='sliding_averaging', threshold='2', look_ahead='9', slide='0.1',
iterations='3')

##run generalisation (step: 3 - snake)
gscript.run_command('v.generalize', flags='l', overwrite=True,
input='segments_douglas_slide', output='segments_douglas_slide_snake',
method='snake', threshold='3', alpha='1', beta='1')
 
 
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