Column Selection

• SDDS_SetColumnFlags -- Sets all column-selection flags to a given value, indicating whether columns are initially ``of interest'' or not). By default, all columns are initially of interest.
• SDDS_SetColumnsOfInterest -- Modifies the ``of interest'' status of columns using lists of column names, wildcard matching, and so forth. General two-term logic is possible using the previous status of each column and the results of newly-requested matching.
• SDDS_DeleteColumn -- Deletes a named column from the current data table of a data set.
• SDDS_DeleteUnsetColumns -- Deletes all ``unset'' columns-i.e., those not declared as ``of interest''.