In the mlxtran model, the following parameters are recognized as individual parameters:
- Only the [LONGITUDINAL] block is present: all parameters of the input list, except those defined as regressors.
- Both the [LONGITUDINAL] and [INDIVIDUAL] blocks are present: parameters defined in the DEFINITION section of the [INDIVIDUAL] block.
Individual parameters can be used in the tab “Exploration” and “Simulation”. An individual parameter definition is either a vector, which has one value per parameter, or a table, where each line correspond to a value of a different individual.
Demo projects: 3.4. individual parameters
New individual parameters elements
After loading a model, Simulx generates automatically a default individual parameter element called “IndivParameters” with all values set to 1. This element can be modified (button EDIT). New elements can be created with the button “+”. Two different types of individual parameter elements are available:
- Manual: One value per parameter to type in. The required parameters are automatically listed.
- External: An external text file with either:
- A single row and one column per parameter. The headers must correspond to the parameter names.
- Several rows, a first column with header “id”, occasion columns (optional) and one column per parameter. The headers must correspond to the parameter names, and to the occasion names if applicable.
- A single row and one column per parameter. The headers must correspond to the parameter names.
The external file can be tab, comma or semicolon separated. Available file extension are: .csv or .txt.
Individual parameters elements imported from Monolix
Upon import of a Monolix run, several individual parameters elements are created automatically:
- mlx_IndivInit: [when POP.PARAM task has not run]a vector of individual parameters corresponding to the initial values of the population parameters in Monolix, i.e with covariate betas and random effects set to zero. For instance, \( V=V_{pop,ini} \)
- mlx_PopIndiv: [when POP.PARAM task has run]a vector of individual parameters corresponding to the population parameters estimated by Monolix, i.e with covariate betas and random effects set to zero. For instance, \( V=V_{pop,est} \)
- mlx_PopIndivCov: [when POP.PARAM task has run and covariates are defined in the Monolix data set]a table of individual parameters corresponding to the population parameters and the impact of the covariates, but random effects set to zero. For instance, \( V=V_{pop} \times \left( \frac{WT}{70} \right) ^{\beta_{V,WT}} \)
- mlx_EBEs: [when EBEs task has run] a table of individual parameters corresponding to the EBEs (conditional mode) estimated by Monolix (as displayed in Monolix Results > Indiv. param > Cond. mode.)
- mlx_CondMean: [when COND. DISTRIB. task has run] a table of individual parameters corresponding to the conditional mean estimated by Monolix (as displayed in in Monolix Results > Indiv. param > Cond. mean.)
- mlx_CondDistSample: [when COND. DISTRIB. task has run] a table of individual parameters corresponding to one sample of the conditional distribution (first replicate of the Monolix result file IndividualParameters/simulatedIndividualParameters.txt).
