# Functions reference

The following CLEM functions are available for working with data in IBM® SPSS® Modeler. You can enter these functions as code in various dialog boxes, such as Derive and Set To Flag nodes, or you can use the Expression Builder to create valid CLEM expressions without memorizing function lists or field names.

Function Type | Description |
---|---|

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 | 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. |

SoundEx | Used to find strings when the precise spelling is not known; based on phonetic assumptions about how certain letters are pronounced. |

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. |