vl.lag(field, param, as)
A lag window operation.
lag Method Overviewlag API Reference# lag.as(value)
The output name for the window operation.
# lag.field(value)
The data field for which to compute the aggregate or window function. This can be omitted for window functions that do not operate over a field such as "count", "rank", "dense_rank".
# lag.op(value)
The window or aggregation operation to apply within a window (e.g., "rank", "lead", "sum", "average" or "count"). See the list of all supported operations here.
# lag.param(value)
Parameter values for the window functions. Parameter values can be omitted for operations that do not accept a parameter.
See the list of all supported operations and their parameters here.