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.
The following categories of functions are available:
| Function type | Description |
|---|---|
| Operators | Lists all the operators you can use when building expressions. Operators are also available from the buttons. |
| Information | Used to gain insight into field values. For example, the function is_string
returns true for all records whose type is a string. |
| Conversion | Used to construct new fields or convert storage type. For example, the function
to_timestamp converts the selected field to a timestamp. |
| Comparison | Used to compare field values to each other or to a specified string. For example,
<= is used to compare whether the values of two fields are lesser or
equal. |
| Logical | Used to perform logical operations, such as if, then, else
operations. |
| Numeric | Used to perform numeric calculations, such as the natural log of field values. |
| Trigonometric | Used to perform trigonometric calculations, such as the arccosine of a specified angle. |
| Probability | Returns probabilities that are based on various distributions, such as probability that a value from Student's t distribution is less than a specific value. |
| Spatial Functions | Used to perform spatial calculations on geospatial data. |
| Bitwise | Used to manipulate integers as bit patterns. |
| Random | Used to randomly select items or generate numbers. |
| String | Used to perform various operations on strings, such as stripchar, which
allows you to remove a specified character. |
| Date and time | Used to perform various operations on date, time, and timestamp fields. |
| Sequence | Used to gain insight into the record sequence of a data set or perform operations that are based on that sequence. |
| Global | Used to access global values that are created by a Set Globals node. For example,
@MEAN is used to refer to the mean average of all values for a field across the
entire data set. |
| Blanks and Null | Used to access, flag, and frequently fill user-specified blanks or system-missing values. For
example, @BLANK(FIELD) is used to raise a true flag for records where blanks are
present. |
| Special Fields | Used to denote the specific fields under examination. For example, @FIELD is
used when deriving multiple fields. |
After you select a group of functions, double-click to insert the functions into the Expression box at the point indicated by the position of the cursor.
Database functions
You can run an SPSS Modeler desktop stream file (.str) that contains database functions. But they aren't yet available in the Expression Builder user interface.