Use scipp

Status

Current

Context

A decision needs to be made about whether to use scipp, numpy, uncertainties or develop our own library for the purpose of providing support for generating uncertanties on our counts data.

Decision

We will be using scipp.

Justification & Consequences

• scipp is being developed at ESS with past input from STFC, so is well suited for neutron counts data.

• scipp has a numpy-like interface but handles units and uncertainties by default under-the-hood.

• Neither numpy or uncertanties have exactly the functionality we would need, so the solution using them would be a mix of the libraries and our own code, there would be more places to go wrong. Maintainability.

• uncertainties package tracks correlations so may have bad scaling on “large” arrays like counts data from the DAE.

• Developing our own uncertainties library will take time to understand and then implement. All of the functionality that we need has been done beforehand, so better to not waste time & effort.

• Less expertise with this library on site (mitigation: don’t do too much which is very complicated with it)

• Potentially duplicates some of mantid’s functionality: (mitigation: use scipp for “simple” things, use mantid in future if people want to do “full” data reduction pipelines)