osmose.engine.processes.selectivity

Fishing selectivity functions for the OSMOSE Python engine.

Selectivity determines what fraction of a species is vulnerable to fishing based on body size. Four types matching Java FisherySelectivity:

0 = knife-edge (age or length)
1 = sigmoid (logistic, parameterized by L50/L75)
2 = Gaussian (normal, peak at L50)
3 = log-normal (right-skewed, normalized by mode)

Functions

gaussian(length, l50, l75[, tiny])

Gaussian (normal) selectivity -- type 2 in Java.

knife_edge(length, l50)

Knife-edge selectivity: 0 below L50, 1 at or above.

log_normal(length, l50, l75[, tiny])

Log-normal selectivity -- type 3 in Java.

sigmoid(length, l50, l75[, tiny])

Logistic sigmoid selectivity -- type 1 in Java.

sigmoid_slope(length, l50[, slope])

Logistic sigmoid selectivity with slope parameter (legacy).