This function returns a function corresponding to the type of curve which was selected to represent the selectivity of nets or hooks.
rtypes_Millar(rtype)
a character string indicating which method for the estimation of selection
curves should be used:
"norm.loc"
for normal with common spread method,
"norm.sca"
for normal with variable spread method,
"lognorm"
for lognormal method,
"binorm.sca"
for bi-normal method,
"bilognorm"
for bi-lognormal method,
"tt.logistic"
for control and logistic method,
"gamma"
for gamma method.
Function adapted from the selectivity functions provided by
Prof. Dr. Russell Millar (https://www.stat.auckland.ac.nz/~millar/).
Until now following curves are incorporated:
"norm.loc"
for a normal curve with common spread,
"norm.sca"
for a normal curve with variable spread,
"lognorm"
for a lognormal curve,
"binorm.sca"
for a bi-normal curve,
"bilognorm"
for a bi-lognormal curve,
"tt.logistic"
for a control and logistic curve.
Millar, R. B., Holst, R., 1997. Estimation of gillnet and hook selectivity using log-linear models. ICES Journal of Marine Science: Journal du Conseil, 54(3), 471-477.