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v0.8.0

Released 2026-05-26 · GitHub Release

Overview​

  • Add the V-SEIR model preset
  • V-SEIHR default initial conditions now seed Exposed and Infected evenly (~0.025% each) instead of putting the full 0.05% seed in Infected.
  • Fix a partial-last-day aggregation issue when simulation.dt < 1: the daily-resampled transition sum on the user-requested end_date was being under-counted by a factor of dt (e.g. half on the last day with dt=0.5). The service now internally pads end_date by one calendar day and trims the trailing day before responding.

Simulations​

POST /api/v1/simulations

New model preset: V-SEIR​

V-SEIR mirrors V-SEIHR minus the hospitalization branch, with the same VE_S semantics on the vaccinated branch. The vaccination block from v0.7.0 works unchanged.

See the V-SEIR preset page for compartments, transitions, parameters, and examples.

V-SEIHR default initial conditions​

The default initial-condition seed for V-SEIHR (used when the request omits an initial_conditions block) was changed from Infected = 0.05%, Susceptible = 99.95% to Exposed = 0.025%, Infected = 0.025%, Susceptible = 99.95%. Because the previous seed had Exposed=0 at t=0, the first E -> I transition could only fire after a full incubation period of build-up, producing a visible discontinuity at step 1 in incidence plots.

Requests that supply an explicit initial_conditions block are unaffected.

Last-day aggregation with sub-daily dt​

When simulation.dt < 1.0 and the output is resampled to daily (resample_frequency="D", the default), the user-requested end_date previously received only one sub-step instead of 1/dt. For example, with dt=0.25 the last day's Exposed_to_Infected count would be roughly a quarter of what it should be.

We have modified the internal simulation logic to ensure that the last day collects the full 1/dt sub-steps when dt < 1.0. The user-facing response shape is unchanged: metadata.simulation.end_date still reports the requested date, and the dates axis ends on it.

Documentation​