Spotfire® Enterprise Runtime for R

TERR_Real

In the Spotfire Custom Expressions dialog box, you can select the pre-defined expression TERR_Real from the Function list. This expression function invokes the TERR engine to return a vector or a single column data frame of the data type numeric , which is converted to a Spotfire column of the corresponding Spotfire data type Real.

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 vector or a single column data frame of data type numeric. A column with the same number of rows as the input, and of the data type Real.

TERR_Real example

This example uses the TERR_PCA_Cars data sample from the Spotfire library. Select four columns (Name, Type, RetailPrice, and DealerCost), and then add a column that calculates a minimum of 5% profit above dealer cost.

TERR_Real("output <- input1*1.05",[DealerCost]))

The resulting table in Spotfire shows the following.


TERR_Real

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.