# Global functions

The functions `@MEAN`, `@SUM`, `@MIN`, `@MAX`, and `@SDEV` work on, at most, all of the records read up to and including the current one. In some cases, however, it is useful to be able to work out how values in the current record compare with values seen in the entire data set. Using a Set Globals node to generate values across the entire data set, you can access these values in a CLEM expression using the global functions.

For example,

``@GLOBAL_MAX(Age) ``

returns the highest value of `Age` in the data set, while the expression

``(Value - @GLOBAL_MEAN(Value)) / @GLOBAL_SDEV(Value) ``

expresses the difference between this record's `Value` and the global mean as a number of standard deviations. You can use global values only after they have been calculated by a Set Globals node.

Table 1. CLEM global functions
Function Result Description
`@GLOBAL_MAX(FIELD)` Number Returns the maximum value for FIELD over the whole data set, as previously generated by a Set Globals node. FIELD must be the name of a numeric, date/time/datetime, or string field. If the corresponding global value has not been set, an error occurs.
`@GLOBAL_MIN(FIELD)` Number Returns the minimum value for FIELD over the whole data set, as previously generated by a Set Globals node. FIELD must be the name of a numeric, date/time/datetime, or string field. If the corresponding global value has not been set, an error occurs.
`@GLOBAL_SDEV(FIELD)` Number Returns the standard deviation of values for FIELD over the whole data set, as previously generated by a Set Globals node. FIELD must be the name of a numeric field. If the corresponding global value has not been set, an error occurs.
`@GLOBAL_MEAN(FIELD)` Number Returns the mean average of values for FIELD over the whole data set, as previously generated by a Set Globals node. FIELD must be the name of a numeric field. If the corresponding global value has not been set, an error occurs.
`@GLOBAL_SUM(FIELD)` Number Returns the sum of values for FIELD over the whole data set, as previously generated by a Set Globals node. FIELD must be the name of a numeric field. If the corresponding global value has not been set, an error occurs.