Syntax

Field specifications can be literal field names, regular expressions or patterns. Those fields for which the entry in the NAME column of the the FIELD sub-table match the literal field name/regular expression/pattern are selected.

If a field name/regular expression/pattern fails to match any field name, the given name/regular expression/pattern are matched against the field code. If still no field is selected, an exception of type MSSelectionFieldParseError is thrown.

Field specifications can also be give by their integer IDs. IDs can be a single ID or a range of IDs (N0$\sim$N1). Field ID selection can also be done using a boolean expression. For a field specification of the form "$>$ID", all field IDs greater than ID are selected. Similarly for "$<$ID" all field IDs smaller than ID are selected.

The field selection expression is a comma-separated list of field specifications. E.g.

• field=1,2,3,4 selects field IDs 1,2,3 and 4
• field=1$\sim$4 same as above
• field=1$\sim$4, VIRGO A , 3C* selects field IDs 1,2,3,4 field named "VIRGO A" and all fields with names starting with "3C".