issue_comments: 918490945

No need to apologize. Some understanding of the data set may help. The MUR-SST data set is a large data set that displays the sea surface temperature (in K) at a given longitude and latitude. The precision is 2 decimal places, so there is a value every .01 deg. The values I displayed above that are nan are expected, as they are over land, and thus can't reflect the sea-surface temperature (this was discovered as part of another search. Ideally I would have liked to find an example where it is completely over water, but I was unable to). Given that, my code opens the dataset generated by PO.DAAC and then each example selects specifically the analysed_sst portion, and then selects the data over a slice of the latitude, where the longitude stays consistent.

From my understanding, the slice mechanism is inclusive on the first value, and exclusive on the second value. Given that, I should from ex_1 get values for (where these are lat/long pairs) (10.47, 68.00), (10.48, 68.00), (10.49, 68.00), (10.50, 68.00), (10.51, 68.00) - and I do receive those values - they correspond to nan, nan, nan, 299.485',299.46`.

However, in ex_2 - I'd additionally expect values for (10.45, 68.00) and (10.46, 68.00) but I only get the additional value for (10.46, 68.00). Additionally, from my understanding, the slice mechanism takes the given input and finds the next nearest sequential value to start at, if the given value does not exist. So in ex_3, I changed the value from 10.45 to 10.449, and I then get a value for (10.45, 68.00). I think at some point there's some math taking place on the given inputs and it's causing that 10.45 to become something like 10.450000000000213 (I have no idea what the value is - this is just an example) and thus, it finds the next sequential value at 10.46. However, I don't know where this is taking place - and whether this is an xarray issue or potentially somewhere else.

Ultimately, for our less technical users, we'd expect them to do slice(10.45, 10.52) and get a value corresponding to 10.45. But unfortunately they do not.