Breaking change: in v4, string model names were removed from wrapper/function APIs.
Use model classes like rms.models.Linear.
What changed?
Removed:model="linear", "quadratic", "cubic" in wrapper/function calls.
Required: pass classes such as model=rms.models.Linear.
No change: direct class instantiation remains valid (rms.Linear(...) and rms.models.Linear(...)).
Before and after
Wrapper API
# v3-style (no longer valid in v4)
model = rms.LinearRegressionModel.fit(data, "x", "y", model="linear")
# v4-style (required)
model = rms.LinearRegressionModel.fit(data, "x", "y", model=rms.models.Linear)
Function API
from regressionmadesimple.api import fit
# v3-style (no longer valid in v4)
model, results = fit(X, y, model="quadratic")
# v4-style (required)
model, results = fit(X, y, model=rms.models.Quadratic)
Migration checklist
Replace string model values with model classes in wrapper calls.
Replace string model values with model classes in function API calls.
Run your tests and confirm no TypeError from model argument usage.
If you were already using rms.models.* classes in v3, migration to v4 should be minimal.