FAQ

This page summarizes the frequent questions about the data set.

  • What are the differences between Monolix and Nonmem in terms of data set? The few differences are listed here.
  • Which column types are mandatory? The ID, TIME and Y column-types are mandatory. All others are optional.
  • Which column-types are possible? The complete list of supported column-types can be found here.
  • Can I have time-varying covariates? Continuous (COV) and categorical (CAT) covariates must be contant within a subject-occasion. Yet continuous covariates can be tagged as regressors (column-type X).
  • Are non-continuous data types (such as count, time-to-event and categorical data) supported? Yes. Exemples of data set for non-continuous data types are presented here.
  • Can my data set contain different types of observations? Yes, use the YTYPE column to define to which type of data the line corresponds. An example data set with different types of observations is presented here.
  • Which file formats are supported? Text and comma-separated values file are allowed. The file extension should preferably be .txt or .csv
  • Which separators are allowed? The supported separators are comma (“,”), semicolon (“;”), space (” “), and tab (“\t”).
  • Which value should I enter in the Y column-type for BLQ values? In the Y column-type, give the limit of quantification (LOQ). To mark the observations as being BLQ, use the CENS column-type. To indicate a censoring interval, use the LIMIT column-type (in addition to the CENS and Y columns).
  • Which characters are allowed in strings? The list of allowed characters can be found here.
  • What does “.” mean? The “.” can be used in almost all the lines of the data set but has several meaning depending on the context. A summary can be found here.
  • What is the equivalent of the NONMEM CMT column? Depending on the usage of the CMT column, it can correspond to the YTYPE column-type, the ADM column-type or to both. All differences between NONMEM and the MonolixSuite are listed here.
  • How are steady-state doses handled? In case of a steady-state dose, 4 additional doses are added before the steady-state dose, in order to reach steady-state. More details can be found here.
  • How can I ignore certain response-lines of my data set? Use MDV=1 for that.
  • Are the MDV and EVID columns necessary? These columns are not mandatory and most of the time not necessary.
  • Which values are allowed for EVID? EVID can takes the values EVID=0 (observation), EVID=1 (dose) and EVID=4 (reset followed by a dose). EVID=2 and EVID=3 are not supported.
  • How can I define a time at which I which the output the predictions, even if I have no observation? Use MDV=2 for this purpose.
  • Must the times be in ascending order? For a given individual, the times do not need to be in order. The sorting will be done automatically.
  • Must all lines corresponding to the same individual be grouped? No, this is not necessary. All lines with the same ID will be assigned to the same individual, whatever their order or grouping.