matplotlib / matplotlib/basemap
spurious horizontal contour lines depending on number of contour levels
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- Dominant language
- Python
- Stars
- 817
- Forks
- 395
- PR merge metrics
- No merged PRs in 30d
Description
I'm seeing an issue where spurious horizontal contour lines appear on my map depending on the number of contour levels I choose. I can also make the horizontal lines go away by 'zooming out' or broadening my plot domain.
Here's an example that has more contour levels and shows the problem (note the two horizontal lines, one near middle of plot, one near bottom):
And here's an example that has less contour levels and the problem goes away:
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First steps
- Read the whole issue, then the project's contributing guide.
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- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the reported map with different numbers of contour levels and plot domains, using the two linked example images as visual references. Trace the contour-rendering entry point responsible for producing the horizontal lines; done means the spurious lines no longer appear while valid contours remain.
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Assessment
- Tech stack
- python
- Domain
- data-visualization
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100