Bug report #8956

Buffers tool does not correctly calculate new shape if "use only selected features" not selected

Added by John L about 11 years ago. Updated over 7 years ago.

Status:Closed
Priority:Normal
Assignee:-
Category:Processing/QGIS
Affected QGIS version:2.0.1 Regression?:
Operating System: Easy fix?:
Pull Request or Patch supplied:No Resolution:invalid
Crashes QGIS or corrupts data:No Copied to github as #:17620

Description

Dataset: congressional voting district data (http://www.census.gov/cgi-bin/geo/shapefilesrd13/main)

Use only selected features: not checked
Segments to approx: 5
Buffer distance to field: Some field with different values per row
Dissolve buffer results: not checked

Im trying to calculate the shape that's the viable interior of each district (exact computation at my website https://sites.google.com/site/mathagainstgerrymandering/advanced-attributes#TOC-Viable-Interior-Index).

Creating the viable interiors one by one ("use only selected feature") works like a charm, but does not create the correct shape if I try to calculate for every district at once.

History

#1 Updated by Giovanni Manghi about 11 years ago

  • Status changed from Open to Feedback
  • Category set to 44

Cannot confirm here, please attach sample data and specify the attribute (in the sample data) you used.

#2 Updated by John L about 11 years ago

Thank you for looking at this Giovanni - I just looked at it again and found the problem instantly.

The buffers layer I am creating does not have the same projection as the underlying layer. Once I created a new project, re-imported the data, and chose the appropriate projection, everything worked like a charm.

#3 Updated by Giovanni Manghi about 11 years ago

  • Resolution set to invalid
  • Status changed from Feedback to Closed

The buffers layer I am creating does not have the same projection as the underlying layer.

this sound strange anyway (I would expect the buffer to be created with the same CRS of the input), but anyway it would be a different issue.

#4 Updated by Giovanni Manghi over 7 years ago

The "ftools" category is being removed from the tracker, changing the category of this ticket to "Processing/QGIS" to not leave the category orphaned.

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