## 5.2 The Pipeline Operator: %>>%

Although it is possible to create intricate Graphs with edges going all over the place (as long as no loops are introduced), there is usually a clear direction of flow between “layers” in the Graph. It is therefore convenient to build up a Graph from layers, which can be done using the %>>% (“double-arrow”) operator. It takes either a PipeOp or a Graph on each of its sides and connects all of the outputs of its left-hand side to one of the inputs each of its right-hand side–the number of inputs therefore must match the number of outputs.

gr = mlr_pipeops$get("scale") %>>% mlr_pipeops$get("pca")
gr\$plot(html = TRUE) %>% visInteraction(zoomView = FALSE) # disable zoom