Description

VectorSlicer is a transformer that takes a feature vector and outputs a new feature vector with a sub-array of the original features. It is useful for extracting features from a vector column.

Parameters

Name Description Type Required？ Default Value
indices indices of a vector to be sliced int[] null
selectedCol Name of the selected column used for processing String ✓
outputCol Name of the output column String null
reservedCols Names of the columns to be retained in the output table String[] null

Script Example

Script

  1. data = np.array([["1:3,2:4,4:7", 1],
  2.     ["0:3,5:5", 3],
  3.     ["2:4,4:5", 4]])
  4. df = pd.DataFrame({"vec" : data[:,0], "id" : data[:,1]})
  5. data = dataframeToOperator(df, schemaStr="vec string, id bigint",op_type="batch")   
  6. vecSlice = VectorSliceBatchOp().setSelectedCol("vec").setOutputCol("vec_slice").setIndices([1,2,3])
  7. vecSlice.linkFrom(data).collectToDataframe()

Result

vec id vec_slice
1:3,2:4,4:7 1 $3$0:3.0 1:4.0
0:3,5:5 3 $3$
2:4,4:5 4 $3$1:4.0