Declaration: TMetaData.GroupIsDefined[Group: integer]: boolean;
The readonly property GroupIsDefined returns TRUE if the spectral group specified by the parameter Group is defined (which means that at least one layer is assigned to this group). The parameter Group may take values between 1 and 4. For group numbers outside this range the function always returns FALSE.

Hint: In order to directly access the metadata of the currently loaded dataset you can use the pre-declared global variable MData.