---
name: DIALS core meeting 2021-09-23
tags: core meeting
---

# DIALS core meeting 2021-09-23

[](https://hackmd.io/3VrcuKsBQ4aL7P3pFXDsMQ)

## Previous Actions

- [ ] "Contiguous Nexus" [`cctbx/dxtbx#356`](https://github.com/cctbx/dxtbx/pull/356)
- [ ] Non-draft state is pending checks against issues @dwpaley raised, and checking for non-contiguous cases [[prev](https://dials.github.io/kb/core/20210715#contiguous-nexus-pr)]
- [ ] dxtbx `src/` layout [[prev](https://dials.github.io/kb/core/20210715#src-layout-for-dxtbx)]
- [ ] Nick: Ask cctbxbb if anyone has knowledge or experience of re-export of dispatchers on windows
- [ ] This is a higher priority now - David feeling pain of missing
- [ ] Also, seeing related errors "in the wild" e.g. [`cctbx/dxtbx#434`](https://github.com/cctbx/dxtbx/pull/434)
- [ ] Removal of DataBlock [[prev](https://dials.github.io/kb/core/20210909#datablock), [prev](https://dials.github.io/kb/core/20210826#removal-of-datablock)]
- [ ] **Nick:** More visible deprecationwarning
- [ ] Impact assessment to see what/who is affected
- [ ] Other repositories - stuff like, iota, prime, ls49, labelit, labelit-regression, xfel-regression, lunus, uc_metrics gitlab/cctbx*, phenix and phenix_regression (phenix.image_viewer)
- DXTBX/pycbf [[prev](https://dials.github.io/kb/core/20210826#cbflib-conda-forge-packagepycbf)]
- Outstanding: [`dxtbx#368`](https://github.com/cctbx/dxtbx/pull/368) for optional cbflib/_adaptbx .
* [ ] ND: conda-forge pycbf: Make new release to use dials-data directly for tests
* [ ] Last status: one `labelit`/`labelit_regression` test still doesn't pass
* All except one labelit tests are now working. On NKS todo list to fix.
* Progress on CBFlib 0.9.7?
- [ ] Nonconventional P1 indexing [[prev](https://dials.github.io/kb/core/20210909#nonconventional-p1-indexing)]
- [ ] RG to look and see how hard it is to return P1 in user-specified order

## Agenda

### Nonconventional P1 indexing
- Problem with P1 indexing not being returned in user-specified setting/order
- Not doing so has XFEL gui repercussions
- Issue at [`dials/dials#1878`](https://github.com/dials/dials/issues/1878)
- Richard has written [`dials/dials#1880`](https://github.com/dials/dials/pull/1880)
- Outstanding test fail on mac/windows - possible numerical instability?

### Deterministic Experiment Identifiers

- ([Previous dicussion](https://dials.github.io/kb/core/20210909#deterministic-experiment-identifiers))
- Previously: It would be useful to describe the problem that is trying to be solved
- LBL had technical discussions:
- cctbx.xfel.merge - modular - can specify which list of workers you want to do in a row. Use case: 380k images - each with 20k reflections - millions into memory. First thing it does is throw away image sets - uses too much memory - even when distributed
- Discussion about `ImageSequence` and why we moved that
- Sounds positive that this might be a good way to solve
- **Action:** Aaron Change `dials.stills_process` to default to composite mode and not write experiment files
- **Action:** Aaron/GW: Organise another meeting to go over ["load before heat death"](https://github.com/cctbx/dxtbx/pull/118) PR and reasons why, solutions etc
- Discussed whether general metadata field would still be useful
- After some spirited discussion, the conclusion was that this would be ripe for abuse - if there is a convincing case then we are happy to reconsider, but shelving for now

### Generating Collection Strategy

- Art: Hit a wall with labelit, wanted to use DIALS
- Have two images, each taken from 90° apart, and wanted to get an indexing solution from this
- Want to use this to help users develop a collection strategy
- Glued various DIALS parts together, integration had issues - reference reflections did not match indexed reflections
- AB: _Strategy_ is a hole in our infrastructure
- Discussion on DIALS East work on `xia2.strategy` and how we were never quite satisfied with it
- Discussed `dials.export_best` and our reasoning about strategy generation from still vs small wedge data
- [Nick] Probably fair to conclude - Strategy is a hole in our _publicliy advertised_ infrastructure

### Next meeting
Thursday, October 7th, 4pm UK (BST), 8am PDT.