Spotfire® Enterprise Runtime for R

TERRAggregation_DateTime

In the Spotfire Custom Expressions dialog box, you can select the pre-defined expression TERRAggregation_DateTime from the Function list. This expression function sets the variable output to a scalar value of the TERR data type POSIXct or POSIXlt, which Spotfire converts to the corresponding Spotfire data type DateTime. The TERR script is called once for each group of data to be aggregated. No special handling for aggregation is necessary in your TERR script.

The expression function has at least two arguments.
Argument Argument description
A TERR script. The TERR script contains the following.
  • A number of variables using the naming convention that Spotfire requires: input1 to inputN, where inputN is the highest number of the specified inputs, numbered sequentally.
  • A TERR assignment operator (<-) that assigns the results of the TERR evaluation to an object named output (also using the naming convention that Spotfire requires).
Spotfire column names. Passed as additional arguments, these are the data column names that input1 to inputN represent. All columns must be the same length.
The output type is returned from TERR and converted by Spotfire.
Returned by TERR Converted in Spotfire
A single aggregated value of data type POSIXct or POSIXlt with the time zone as UTC. Any data specified as NA in TERR maps to null in Spotfire.

Do not use the date data type. (Spotfire converts date to data type Real.)

A single aggregated value of data type DateTime.

TERRAggregation_DateTime

TERRAggregation_DateTime("output <-max(input1, 'mins')", [X])
Important: Spotfire autocorrects the function case or name to that of built-in Spotfire function names. (For example, TERR contains the function max, and Spotfire contains the function Max. ) You must overwrite this autocorrection manually to ensure that you use the TERR function case and name in your expression function.

See Embedding the Contents of a Script in an Expression Function for a detailed procedure for creating an expression function.