apache / incubator-retired-mrql / ab6bac73711b0d5fa5f05fa2c9b4c558c0576042 / . / queries / kmeans.mrql

/** | |

* Licensed to the Apache Software Foundation (ASF) under one | |

* or more contributor license agreements. See the NOTICE file | |

* distributed with this work for additional information | |

* regarding copyright ownership. The ASF licenses this file | |

* to you under the Apache License, Version 2.0 (the | |

* "License"); you may not use this file except in compliance | |

* with the License. You may obtain a copy of the License at | |

* | |

* http://www.apache.org/licenses/LICENSE-2.0 | |

* | |

* Unless required by applicable law or agreed to in writing, software | |

* distributed under the License is distributed on an "AS IS" BASIS, | |

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |

* See the License for the specific language governing permissions and | |

* limitations under the License. | |

*/ | |

type point = < X: double, Y: double >; | |

function distance ( x: point, y: point ): double { | |

sqrt(pow(x.X-y.X,2)+pow(x.Y-y.Y,2)) | |

}; | |

aggregation new_centroid ( | |

\(p:(point,long),q:(point,long)):(point,long) | |

.( < X: p#0.X+q#0.X, Y: p#0.Y+q#0.Y >, | |

p#1+q#1), | |

( < X: 0.0 as double, Y :0.0 as double >, 0 as long ) | |

) : (point,long); | |

function centroid ( p: (point,long), default: point ): point { | |

if p#1 = 0 | |

then default | |

else < X: p#0.X/p#1, Y: p#0.Y/p#1 > | |

}; | |

repeat centroids = { < X: 0.0 as double, Y: 0.0 as double >, | |

< X: 10.0, Y: 0.0 >, | |

< X: 0.0, Y: 10.0 >, | |

< X: 10.0, Y: 10.0 > } | |

step select ( centroid(new_centroid(select (p,1 as long) from p in s),k), true ) | |

from s in source(binary,"tmp/points.bin") | |

group by k: (select c from c in centroids order by distance(c,s))[0] | |

limit 5; |