[source] # Lambda Function Run a stateless lambda function over the samples in a dataset. The function receives three arguments - the sample to be transformed, its row offset in the dataset, and a user-defined outside context variable that can be used to hold state. **Note:** If the transformation results in a change in dimensionality, the change must be consistent for each sample. **Interfaces:** [Transformer](api.md#transformer) **Compatibility** Depends on callback function ## Parameters | # | Param | Default | Type | Description | |---|---|---|---|---| | 1 | callback | | callable | The function to call over the samples in the dataset. | | 2 | context | null | mixed | The outside context that gets injected into the callback function on each call. | ## Example ```php use Rubix\ML\Transformers\LambdaFunction; $callback = function (&$sample, $offset, $context) { $sample[] = log1p($sample[3]); }; $transformer = new LambdaFunction($callback, 'example context'); ``` ## Additional Methods This transformer does not have any additional methods.