Create a model using only the most important features in another one

metadata.json

{
  "name": "select-important",
  "kind": "script",
  "description": "Select the important features from an existig moddel to create a new one",
  "source_code": "script.whizzml",
  "imports":[
    ],
  "inputs":[
    {
      "name": "model-id",
      "type": "model-id",
      "description": "Known model from which to infer important features"
    },
    {
      "name": "feature-no",
      "type": "number",
      "description": "Number of important features to retain"
    },
    {
      "name": "dataset-id",
      "type": "dataset-id",
      "description": "Dataset to model uisng the most important features"
    }],
  "outputs":[
    {
      "name": "model-id",
      "type": "model-id",
      "description": "The newly created model"
    }]
}

script.whizzml

(define (mark-fields ds-id prefix)
  (let (fields (resource-fields ds-id)
        ids (keys fields)
        len (count prefix)
        flags (for (f (values fields))
                {"preferred" (not (= prefix (subs (f "name") 0 len)))}))
    (update ds-id {"fields" (make-map ids flags)})))

(define result (mark-fields dataset-id prefix))

The input should be any of the "models" and I see no difference between the input and output model. :-)