stilt.config.ModelConfig.setup_seed

static ModelConfig.setup_seed(seed)

Map a user seed to the SEED value written to SETUP.CFG.

HYSPLIT sets its generator state to -1 + SEED and, under krand=2, re-initializes only from a negative value, collapsing every value >= -1 onto the same stream. -(|seed| + 1) keeps the state at -(|seed| + 2): negative, distinct per |seed|, and never the unseeded default. A patched HYSPLIT that honours SEED directly maps a negative SEED to the same state, so the value is portable.

Return type:

int

Parameters:

seed (int)