# mlr_pipeops_featureunion

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##### PipeOpFeatureUnion

Aggregates features from all input tasks by cbind()ing them together into a single Task.

DataBackend primary keys and Task targets have to be equal across all Tasks. Only the target column(s) of the first Task are kept.

If assert_targets_equal is TRUE then target column names are compared and an error is thrown if they differ across inputs.

Keywords
datasets
##### Format

R6Class object inheriting from PipeOp.

##### Parameters

PipeOpFeatureUnion has no Parameters.

PipeOpFeatureUnion uses the Task $cbind() method to bind the input values beyond the first input to the first Task. This means if the Tasks are database-backed, all of them except the first will be fetched into R memory for this. This behaviour may change in the future. ##### Fields Only fields inherited from PipeOp. ##### Methods Only methods inherited from PipeOp. ##### See Also ##### Aliases • mlr_pipeops_featureunion • PipeOpFeatureUnion ##### Examples # NOT RUN { library("mlr3") task = tsk("iris") gr = gunion(list( po("nop"), po("pca") )) %>>% po("featureunion") gr$train(task)

po = po("featureunion", innum = c("a", "b"))