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/issues/5901#issuecomment-953641308,https://api.github.com/repos/pydata/xarray/issues/5901,953641308,IC_kwDOAMm_X84412lc,1562854,2021-10-28T08:48:55Z,2021-10-28T08:48:55Z,CONTRIBUTOR,"Just to explain the issue a bit: `pcolormesh(x, y, Z, shading='flat')` was the default.  If `shape(Z)` used to be `(len(y), len(x))` matplotlib would drop, without warning, the last row and column of Z so that y and x were one larger than Z.  

The new default is `'auto'` where in the case above it uses `shading='nearest'` to create new x and y co-ordinates with the dumbest algorithm possible of placing them in the midpoints, and adding two new points on the outside.  So rather than drop data from Z, we _add_ to the _x_ and _y_ co-ordinates.  

That is usually fine, except the midpoint between 0 and 360 is 180, and we get a weird wrap.  Cartopy (xarray) accounted for this with the old shading by adding a NaN.  I've not followed what they are doing now. 

To get the old behaviour you simply need to do `pcolormesh(x, y, Z[:-1, :-1], shading='flat')` _or_ make x and y one larger than Z in each dimension and specify the the corners of the quadrilaterals.  

Sorry this is a pain, but the old behaviour of silently dropping data, while having a long lineage going back to Matlab, was deemed unacceptable.  However, if this continues to be a nuisance to folks, I'm sure matplotlib would consider a new shading argument, something like `'flat-drop'`, or somesuch that would do the data dropping for you.  ","{""total_count"": 2, ""+1"": 2, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,1037814301