Version 3.5.2

[cliffckerr]

Version 3.5.2 (2026-07-14)

• Starsim v3.5.0 added several optimizations affecting how random numbers are drawn. However, these changes introduced several dtype-related bugs that have been fixed in this release:

  • Fixed a bug where ss.random() always returned float64 regardless of the configured type ss.dtypes.float.
  • Fixed ss.poisson() sometimes returning float64 and sometimes returning an integer. It now always returns ss.dtypes.int.
  • Fixed ss.multi_random.rvs() returning an incorrect number of samples due to type mismatches.
  • Regression: Because the default CRN mechanism precision has changed to consistently match ss.dtypes.float, the exact random values produced for agent-indexed draws are different from v3.5.1.

• ss.uids() now performs additional validation to more consistently ensure it only contains integers.

  • Migration: Previously ss.uids([1.5]) would convert the input to an integer and thus return ss.uids([1]). However, because this usage would often reflect an error, this operation will now raise a TypeError to prevent inadvertent conversion of floats silently succeeding. To maintain previous functionality, convert the input to integers before calling ss.uids().

• Timeline.now() returns durations rather than bare floats, for simulations that use duration-based units.

• Made the folder argument of ss.Samples optional, and moved it from first to third.

  • Migration: Positionally-created Samples should use kwargs instead, e.g. ss.Samples(resultsdir, outputs) should be changed to ss.Samples(outputs, folder=resultsdir).

• GitHub info: PR 1393

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This discussion was created from the release Version 3.5.2.