Opened 5 years ago

Closed 5 years ago

Last modified 4 years ago

#2563 closed enhancement (invalid)

r.grow.distance: define max distance

Reported by: mlennert Owned by: grass-dev@…
Priority: normal Milestone: 7.2.0
Component: Raster Version: svn-trunk
Keywords: r.grow.distance maximum distance Cc:
CPU: Unspecified Platform: Unspecified

Description

It would be nice if r.grow.distance allowed to define a maximum distance. The module could then stop calculating once this maximum distance is attained (e.g. similar to r.cost's max_cost option). This should probably accelerate the module if only short distances are needed from the starting points.

Change History (3)

comment:1 in reply to:  description ; Changed 5 years ago by glynn

Replying to mlennert:

It would be nice if r.grow.distance allowed to define a maximum distance. The module could then stop calculating once this maximum distance is attained (e.g. similar to r.cost's max_cost option). This should probably accelerate the module if only short distances are needed from the starting points.

It wouldn't have the slightest effect upon performance. r.grow.distance doesn't operate in order of increasing distance. It operates row-by-row in two passes, from top-to-bottom then bottom-to-top, recording the distance to the closest point seen so far.

comment:2 in reply to:  1 Changed 5 years ago by mlennert

Resolution: invalid
Status: newclosed

Replying to glynn:

Replying to mlennert:

It would be nice if r.grow.distance allowed to define a maximum distance. The module could then stop calculating once this maximum distance is attained (e.g. similar to r.cost's max_cost option). This should probably accelerate the module if only short distances are needed from the starting points.

It wouldn't have the slightest effect upon performance. r.grow.distance doesn't operate in order of increasing distance. It operates row-by-row in two passes, from top-to-bottom then bottom-to-top, recording the distance to the closest point seen so far.

Ok, so the only way to limit the distance is to determine the smallest region that would include the max distance.

Closing this as invalid.

comment:3 Changed 4 years ago by neteler

Milestone: 7.1.07.2.0

Milestone renamed

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