Filter Transform
The filter transform removes objects from a data stream based on a provided filter expression.
Transform Parameters
| Property | Type | Description |
|---|---|---|
| expr | Expr | Required. A predicate expression for filtering the data. If the expression evaluates to false, the data object will be filtered. |
Usage
{"type": "filter", "expr": "datum.x > 10"}
This example retains only data elements for which the field x is greater than 10.
{"type": "filter", "expr": "log(datum.y) / LN10 > 2"}
This example retains only data elements for which the base-10 logarithm of y is greater than 2.