rf = rowfilter(names)
expr = rf.VariableName operator value
T = expr.apply(T)
| Parameter | Description |
|---|---|
| names | variable names specified as a string array or cell array of character vectors. |
| T | a table or timetable. |
| Parameter | Description |
|---|---|
| rf | a nelson.io.RowFilter object. |
| expr | a nelson.io.RowFilter object containing a filter expression. |
nelson.io.RowFilter stores the variable names and expression used to select rows.
Variable names are accessed with dot notation. Relational and logical operators create a filter expression. The expression is evaluated when apply is called or when the object is used as a RowFilter argument for Parquet reading functions.
The variables method returns the names referenced by the expression.
T = table([1; 2; 3; 4], [10; 20; 30; 40], ...
'VariableNames', {'Id', 'Value'});
rf = rowfilter({'Id', 'Value'});
expr = rf.Id > 1 & rf.Value <= 30;
expr.variables()
R = expr.apply(T)| Version | Description |
|---|---|
| 2.0.0 | initial version |