derive_derived_param {admiral}R Documentation

Adds a Parameter Computed from the Analysis Value of Other Parameters



This function is deprecated. Please use derive_param-computed() instead.


  filter = NULL,
  constant_by_vars = NULL,
  constant_parameters = NULL



Input dataset

The variables specified by the by_vars parameter, PARAMCD, and AVAL are expected.

The variable specified by by_vars and PARAMCD must be a unique key of the input dataset after restricting it by the filter condition (filter parameter) and to the parameters specified by parameters.


Grouping variables

For each group defined by by_vars an observation is added to the output dataset. Only variables specified in by_vars will be populated in the newly created records.

Permitted Values: list of variables


Required parameter codes

It is expected that all parameter codes (PARAMCD) which are required to derive the new parameter are specified for this parameter or the constant_parameters parameter.

Permitted Values: A character vector of PARAMCD values


Definition of the analysis value

An expression defining the analysis value (AVAL) of the new parameter is expected. The analysis values of the parameters specified by parameters can be accessed using ⁠AVAL.<parameter code>⁠, e.g., AVAL.SYSBP.

Permitted Values: An unquoted expression


Variables to be set

The specified variables are set to the specified values for the new observations. For example vars(PARAMCD = "MAP") defines the parameter code for the new parameter.

Permitted Values: List of variable-value pairs


Filter condition

The specified condition is applied to the input dataset before deriving the new parameter, i.e., only observations fulfilling the condition are taken into account.

Permitted Values: a condition


By variables for constant parameters

The constant parameters (parameters that are measured only once) are merged to the other parameters using the specified variables. (Refer to Example 2)

Permitted Values: list of variables


Required constant parameter codes

It is expected that all the parameter codes (PARAMCD) which are required to derive the new parameter and are measured only once are specified here. For example if BMI should be derived and height is measured only once while weight is measured at each visit. Height could be specified in the constant_parameters parameter. (Refer to Example 2)

Permitted Values: A character vector of PARAMCD values


The input dataset with the new parameter added. Note, a variable will only be populated in the new parameter rows if it is specified in by_vars.


Stefan Bundfuss

See Also

Other deprecated: derive_var_aendy()

[Package admiral version 0.8.4 Index]