Use this field to specify the variables whose values determine the column names in the tall data set.If you leave this field blank , the column names are specified as "Prefix"1 - "Prefix"n for the prefix given in the Prefix for Tall Column Names field, or Col1 - Coln if no prefix is specified.If you specify multiple variables, their combined values must be unique for each row.All of the variables in the specified input data set are displayed in the Available Variables field.
Highlight one or more variables. To highlight multiple variables at once, hold down while left-clicking on them.
Click to add the highlighted variable(s) to the Variables Defining Tall Column Names field, as shown below: