Selecting functions

The function list displays all available CLEM functions and operators. Scroll to select a function from the list, or, for easier searching, use the drop-down list to display a subset of functions or operators. Available functions are grouped into categories for easier searching.

Most of these categories are described in the Reference section of the CLEM language description. For more information, see Functions reference.

The other categories are as follows.

• General Functions contains a selection of some of the most commonly-used functions.
• Recently Used contains a list of CLEM functions used within the current session.
• @ Functions contains a list of all the special functions, which have their names preceded by an "@" sign.
  Note: The @DIFF1(FIELD1,FIELD2) and @DIFF2(FIELD1,FIELD2) functions require that the two field types are the same (for example, both Integer or both Long or both Real).
• Database Functions. If the stream includes a database connection (by means of a Database source node), this selection lists the functions available from within that database, including user-defined functions (UDFs). For more information, see Database functions.
• Database Aggregates. If the stream includes a database connection (by means of a Database source node), this selection lists the aggregation options available from within that database. These options are available in the Expression Builder of the Aggregate node.
• Database Window Aggregates. If the stream includes a database connection (by means of a Database source node), this selection lists the window aggregation options that you can use within that database. These options are available in the Expression Builder within nodes in the Field Operations palette only.
  Note: Because SPSS® Modeler obtains the Window Aggregate Functions from the Database System View, the available options are dependent on Database behavior.

  Although called "aggregates" these options are not designed for use in the Aggregate node; they are more applicable to nodes such as Derive or Select. This is because their output is scalar instead of a true aggregate; that is, they do not reduce the amount of data shown in the output in the same way that the Aggregate node does. For example, you could use this sort of aggregation to provide a moving average down through rows of data, such as "average of the current row and all previous rows".

• Built-In Aggregates. Contains a list of the possible modes of aggregation that can be used.
• Operators lists all the operators you can use when building expressions. Operators are also available from the buttons in the center of the dialog box.
• All Functions contains a complete list of available CLEM functions.

After you have selected a group of functions, double-click to insert the functions into the expression field at the point indicated by the position of the cursor.