add_iiv#

pharmpy.modeling.add_iiv(model, list_of_parameters, expression, operation='*', initial_estimate=0.09, eta_names=None)[source]#

Adds IIVs to pharmpy.model.

Effects that currently have templates are:

• Additive (add)

• Proportional (prop)

• Exponential (exp)

• Logit (log)

• Rescaled logit (re_log)

For all except exponential the operation input is not needed. Otherwise user specified input is supported. Initial estimates for new etas are 0.09.

Assuming a statement $CL=\mathrm{\Theta }$, IIVs are added in the following ways:

• Additive: $CL=\mathrm{\Theta }+\eta$

• Proportional: $CL=\mathrm{\Theta }\cdot (1+\eta )$

• Exponential: $CL=\mathrm{\Theta }+/\cdot e^{\eta }$

• Logit: $CL=\mathrm{\Theta }\cdot e^{\eta }/(e^{\eta }+1)$

• Rescaled logit: $CL=e^{\mathrm{\Phi }\cdot \eta }/(1+e^{\mathrm{\Phi }\cdot \eta })$ with $\mathrm{\Phi }=log(\mathrm{\Theta }/(1-\mathrm{\Theta }))$

Parameters:

• model (Model) – Pharmpy model to add new IIVs to.

• list_of_parameters (str, list) – Name/names of parameter to add new IIVs to.

• expression (str, list) – Effect/effects on eta. Either abbreviated (see above) or custom.

• operation (str, list, optional) – Whether the new IIV should be added or multiplied (default).

• initial_estimate (float) – Value of initial estimate of parameter. Default is 0.09

• eta_names (str, list, optional) – Custom name/names of new eta

Returns:

Model – Pharmpy model object

Example

>>> from pharmpy.modeling import *
>>> model = load_example_model("pheno")
>>> model = remove_iiv(model, "CL")
>>> model = add_iiv(model, "CL", "add")
>>> model.statements.find_assignment("CL")
CL = ETA_CL + TVCL

See also

add_pk_iiv, add_iov, remove_iiv, remove_iov