Define relationship between parameters and covariates
Expression property is a string or cell
array of strings, where each string represents the relationship between
a parameter and one or more covariates. The
denotes fixed effects with the prefix
random effects with the prefix
Each expression string must be in the form:
This example of an expression string defines the relationship
between a parameter (
volume) and a covariate (
with fixed effects, but no random effects:
This table illustrates expression formats for some common parameter-covariate relationships.
|Parameter-Covariate Relationship||Expression Format|
|Linear with random effect|
|Exponential without random effect|
|Exponential, WEIGHT centered by mean, has random effect|
|Exponential, log(WEIGHT), which is equivalent to power model|
|Exponential, dependent on WEIGHT and AGE, has random effect|
|Inverse of probit, dependent on WEIGHT and AGE, has random effect|
|Inverse of logit, dependent on WEIGHT and AGE, has random effect|
To simultaneously fit data from multiple dose levels, use a
Expression property must meet the following
The expression strings are valid MATLAB® code.
Each expression string is linear with a transformation.
There is exactly one expression string for each parameter.
In each expression string, a covariate is used in at most one term.
In each expression string, there is at most one random
Fixed effect (
theta) and random
eta) names are unique within and across
expression strings. That is, each covariate has its own fixed effect.
|Applies to||Object: |
|Data type||String or cell array of strings|