swiftsimio.subset_writer module

Functions for reading a subset of a SWIFT dataset and writing it to a new file.

swiftsimio.subset_writer.write_subset(output_file: str, mask: SWIFTMask, allow_unconstrained: bool = False) → None[source]

Write subset of data according to specified mask to new data file.

Parameters:

  • output_file (str) – Path to output file for data subset.

  • mask (SWIFTMask) – The mask used to define subset that is written to new snapshot.

  • allow_unconstrained (bool) – Set to True to allow a mask with no constraints applied, this would normally result in a full copy of the data to a new file.

Raises:

ValueError – If the mask has no constraints applied, unless allow_unconstrained is set to True.