<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi all,<div class=""><br class=""></div><div class="">Matt asked someone to send a quick note about the current issues regarding the ytdata frontend PR:</div><div class=""><br class=""></div><div class=""><a href="https://bitbucket.org/yt_analysis/yt/pull-requests/1788/adding-ytdata-frontend" class="">https://bitbucket.org/yt_analysis/yt/pull-requests/1788/adding-ytdata-frontend</a></div><div class=""><br class=""></div><div class="">I’m sending it because I’m working on it currently, but I was not able to attend today’s PR hangout so anyone else who was more to add or to correct should chime in. </div><div class=""><br class=""></div><div class="">Currently, there are 3 issues, from most important to least important:</div><div class=""><br class=""></div><div class="">1. Tests don’t work</div><div class="">2. Doesn’t support Python 3</div><div class="">3. Derived quantities don’t work</div><div class=""><br class=""></div><div class="">I’m currently working on 1 and 2, and there have been some ideas about 3. The main issue with the latter is that for non-gridded data containers (like sphere, disk, etc.) created from grid datasets, we treat the new datasets as “particle data”. For that reason there is an issue with calculating the cell_volume properly. Without that, we cannot use the total_mass() quantity. Given that we have the cell deltas in the dataset, we could have a special derived field for the cell_volume. </div><div class=""><br class=""></div><div class="">There are other issues with some of the other derived quantities (e.g., weighted_average_quantity returning the wrong units), but I haven’t been able to diagnose them yet. </div><div class=""><br class=""></div><div class="">I’m working on some changes that will need to be merged into Britton’s fork eventually to address at least 1 and 2.</div><div class=""><br class=""></div><div class="">Best,</div><div class=""><br class=""></div><div class="">John</div></body></html>