The field statistics computes statistical quantities from a field. The commands reduce the information of the field to one quantity, which is stored in a given field. If the output data has been given, then the operation creates a data frame and adds a field to it. Otherwise, a new field is created directly under a directory.
The form of the result is a column matrix in which one statistical quantity over all the fields is stored in one field. A data record corresponds to a field in the source data. This differs from the class statistics in which data records correspond to classes.
Now new fields are named by the name of the target data and an extension which describes the procedure used.
Each operation may take a missing value as a parameter. If the parameter is given, then the defined value is skipped when computing the statistics.
Example (ex4.7): A typical use of the field statistics is to compute minimum and maximum values from a data for some scaling task.
... NDA> fldstat -d boston -dout mmstat -min -max NDA> ls -fr mmstat.min mmstat.max