html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/pull/1972#issuecomment-374573132,https://api.github.com/repos/pydata/xarray/issues/1972,374573132,MDEyOklzc3VlQ29tbWVudDM3NDU3MzEzMg==,12229877,2018-03-20T12:03:13Z,2018-03-20T12:03:13Z,CONTRIBUTOR,"> I would say we should merge it now and iterate in future PRs.
Merge away then!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-373545890,https://api.github.com/repos/pydata/xarray/issues/1972,373545890,MDEyOklzc3VlQ29tbWVudDM3MzU0NTg5MA==,12229877,2018-03-15T22:41:20Z,2018-03-15T22:41:20Z,CONTRIBUTOR,"@shoyer & @fmaussion - I've just given up on the plotting tests as being more effort than they're worth. Are there any:
- blockers to merging this as-is?
- other APIs you think it would be reasonably easy to write property tests for? [Here's a nice list of properties](https://fsharpforfunandprofit.com/posts/property-based-testing-2/) to test :smile: ","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371796211,https://api.github.com/repos/pydata/xarray/issues/1972,371796211,MDEyOklzc3VlQ29tbWVudDM3MTc5NjIxMQ==,12229877,2018-03-09T12:11:02Z,2018-03-09T12:11:02Z,CONTRIBUTOR,"@jklymak - I'm getting `RuntimeError: Invalid DISPLAY variable` in the Qt backend now that I've added `plt.clf()`. It works on my machine now (:tada:, thanks!) - any suggestions for Travis?
(I'm also getting Zarr errors, but I assume those will go away soon as I didn't cause them)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371722392,https://api.github.com/repos/pydata/xarray/issues/1972,371722392,MDEyOklzc3VlQ29tbWVudDM3MTcyMjM5Mg==,12229877,2018-03-09T06:05:46Z,2018-03-09T06:05:46Z,CONTRIBUTOR,"...that also explains why I was having trouble reproducing the error, whoops. I'll see how it goes with those problems excluded later tonight!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371718795,https://api.github.com/repos/pydata/xarray/issues/1972,371718795,MDEyOklzc3VlQ29tbWVudDM3MTcxODc5NQ==,1562854,2018-03-09T05:38:23Z,2018-03-09T05:38:23Z,CONTRIBUTOR,"As pointed out on the matplotlib gitter:
If you run
```python
import numpy as np
import xarray as xr
import matplotlib.pyplot as plt
for i in range(200):
xr.DataArray(np.array([[0, 0], [0, 0]], dtype=np.uint8)).plot.pcolormesh()
```
at step 165 you will get:
```
File ""/Users/jklymak/matplotlib/lib/matplotlib/figure.py"", line 236, in update
raise ValueError('left cannot be >= right')
ValueError: left cannot be >= right
```
Why? Because you have made a plot that if it displays looks like:
Are you sure your test isn't doing something similar? At some point there just isn't room for more colorbars! Adding a `plt.clf()` can cure the problem.
Its also is possible you are hitting floating point overflows with your test. At some point Matplotlib needs to be able to manipulate the data that comes in, and if you operate near the maximum number your data type can handle, you'll have problems. Just like you would if you just did
```python
a = 2*xr.DataArray(np.array([[0, 0], [0, 1e308]]))
```
you will get:
```
/Users/jklymak/anaconda3/envs/matplotlibdev/lib/python3.6/site-packages/xarray/core/variable.py:1165: RuntimeWarning: overflow encountered in multiply
```
So maybe your hypothesis tester could be constrained to stay away from floating point overflows?
Matplotlib indeed has flaws and quirks, but if you are finding bugs it would be good to isolate them.
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371689343,https://api.github.com/repos/pydata/xarray/issues/1972,371689343,MDEyOklzc3VlQ29tbWVudDM3MTY4OTM0Mw==,12229877,2018-03-09T02:05:18Z,2018-03-09T02:05:39Z,CONTRIBUTOR,"@shoyer - that depends mostly on whether you want to run these tests as part of a standard run. A test-time dependency on Hypothesis is very cheap compared to the other dev dependencies, so I'd think more about the impact on eg CI resources than contributors.
Upside is more power and coverage of edge-cases with odd data; downside is that they take a lot longer by virtue of trying hundreds of examples, and in this case also having to generate arrays takes a while (~log(elements) average via sparse filling).
-------
@tacaswell - I would be delighted to write a test suite like this for matplotlib! The only reason I *haven't* is because I thought it would be rude to report so many bugs that I don't have time to help fix. If we can get a group project going though I'd be very enthusiastic 😄
- For this suite I was passing in 2D arrays of unsigned ints, signed ints, or floats (in all sizes), with edge sizes between 2 and 10.
- The failing outputs were reported as 2x2 arrays (~30 times), or 3x2 (once - there's a cap on number of shrinks that I think I hit there).
- Values tended to be either uniform small integers - 0 or 1, dtype int8 or uint8; or for some an array of floats with one corner zero and the others *very* large.
I didn't keep the exact tracebacks, but I remember seeing many come from overflow in tick spacing calculations. Again, happy to write a test suite and make more detailed reports upstream if people want to fix this - in which case let's open an issue there!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371671971,https://api.github.com/repos/pydata/xarray/issues/1972,371671971,MDEyOklzc3VlQ29tbWVudDM3MTY3MTk3MQ==,12229877,2018-03-09T00:26:13Z,2018-03-09T00:26:13Z,CONTRIBUTOR,"> This looks like a great start to me -- thank you!
You're welcome! Same questions as above though, plus ""is there anything else you need in this initial PR?"". If not, can we merge it
> It's impressive that it's possible to break every plotting type with matplotlib :).
As much as I love matplotlib, it's a steaming pile of hacks and I want to avoid it more than I want it cleaned up 😥 (entirely because the process is dysfunctional, not the code)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716
https://github.com/pydata/xarray/pull/1972#issuecomment-371403712,https://api.github.com/repos/pydata/xarray/issues/1972,371403712,MDEyOklzc3VlQ29tbWVudDM3MTQwMzcxMg==,12229877,2018-03-08T07:29:18Z,2018-03-08T07:29:18Z,CONTRIBUTOR,"Ping @fmaussion / @shoyer - would love your opinions on this, including high-value targets to test.
(btw Appveyor had an internal error; build is otherwise green)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,303103716