Description
Bisecting k-means is a kind of hierarchical clustering algorithm.
Bisecting k-means algorithm starts from a single cluster that contains all points. Iteratively it finds divisible clusters on the bottom level and bisects each of them using k-means, until there are k
leaf clusters in total or no leaf clusters are divisible.
Parameters
Name | Description | Type | Required? | Default Value |
---|---|---|---|---|
minDivisibleClusterSize | Minimum divisible cluster size | Integer | 1 | |
k | Number of clusters. | Integer | 4 | |
distanceType | Distance type for clustering, support EUCLIDEAN and COSINE. | String | “EUCLIDEAN” | |
vectorCol | Name of a vector column | String | ✓ | |
maxIter | Maximum iterations, The default value is 10 | Integer | 10 |
Script Example
Code
import numpy as np
import pandas as pd
data = np.array([
[0, "0 0 0"],
[1, "0.1,0.1,0.1"],
[2, "0.2,0.2,0.2"],
[3, "9 9 9"],
[4, "9.1 9.1 9.1"],
[5, "9.2 9.2 9.2"]
])
df = pd.DataFrame({"id": data[:, 0], "vec": data[:, 1]})
inOp1 = BatchOperator.fromDataframe(df, schemaStr='id int, vec string')
inOp2 = StreamOperator.fromDataframe(df, schemaStr='id int, vec string')
kmeans = BisectingKMeansTrainBatchOp().setVectorCol("vec").setK(2)
predictBatch = BisectingKMeansPredictBatchOp().setPredictionCol("pred")
kmeans.linkFrom(inOp1)
predictBatch.linkFrom(kmeans, inOp1)
[model,predict] = collectToDataframes(kmeans, predictBatch)
print(model)
print(predict)
predictStream = BisectingKMeansPredictStreamOp(kmeans).setPredictionCol("pred")
predictStream.linkFrom(inOp2)
predictStream.print(refreshInterval=-1)
StreamOperator.execute()
Results
Model
rowId model_id model_info
0 0 {"vectorCol":"\"vec\"","distanceType":"\"EUCLI...
1 1048576 {"clusterId":1,"size":6,"center":{"data":[4.6,...
2 2097152 {"clusterId":2,"size":3,"center":{"data":[0.1,...
3 3145728 {"clusterId":3,"size":3,"center":{"data":[9.1,...
Prediction
rowId id vec pred
0 0 0 0 0 0
1 1 0.1,0.1,0.1 0
2 2 0.2,0.2,0.2 0
3 3 9 9 9 1
4 4 9.1 9.1 9.1 1
5 5 9.2 9.2 9.2 1