| 
           none | dataset name 
         | 
        |||
| 
           missingmass | none 
         | 
        |||
| 
           none | function name 
         | 
        |||
| 
           none | function name 
         | 
        |||
| 
           frequency | periodtime 
         | 
        |||
| 
           none | function name 
         | 
        |||
| 
           Zero period acceleration frequency (when rigidmodes is not none). Available when spatialcomb is srss or percent. 
         |