如何为mlpack的kmeans构造HamerlyKmeans对象

Question

我是mlpack和使用3.3.1的新手。我想做一些KMeans集群。我可以很好地使用naiveKMeans类，但是我想使用另一个方法，例如HamelyKMeans类。

从手册中看，我似乎需要构造自己的该类本地对象来传递它，而不是下面这行代码中的NaiveKMeans：

  KMeans<mlpack::metric::EuclideanDistance, kmeans::SampleInitialization,
    kmeans::MaxVarianceNewCluster, kmeans::NaiveKMeans, arma::mat> km =KMeans(0);

但是当我尝试按如下方式构造它时，我得到了一个编译器错误：

// for StackOverflow
#include <mlpack/prereqs.hpp>
#include <mlpack/core.hpp>
#include <mlpack/core/util/cli.hpp>
#include <mlpack/methods/kmeans/kmeans.hpp>
#include <mlpack/methods/kmeans/allow_empty_clusters.hpp>
#include <mlpack/methods/kmeans/kill_empty_clusters.hpp>
#include <mlpack/methods/kmeans/refined_start.hpp>
#include <mlpack/methods/kmeans/elkan_kmeans.hpp>
#include <mlpack/methods/kmeans/hamerly_kmeans.hpp>
#include <mlpack/methods/kmeans/pelleg_moore_kmeans.hpp>
#include <mlpack/methods/kmeans/dual_tree_kmeans.hpp>
using namespace mlpack;
using namespace mlpack::kmeans;
using namespace mlpack::metric;
using namespace mlpack::util;

int main(int argc, char **argv) {
  arma::mat in_data(10,10);
  for ( int i=0; i < 10; i++ ) {

    for ( int j=0; j < 10; j++ ) {
        in_data(j,i)=i+j;
    }
  }
  kmeans::HamerlyKMeans< metric::EuclideanDistance, arma::mat> 
ek = kmeans::HamerlyKMeans(in_data,EuclideanDistance());
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^                                

// HamerlyKMeans to be used instead of NaiveKMeans below


  KMeans<mlpack::metric::EuclideanDistance, kmeans::SampleInitialization,
    kmeans::MaxVarianceNewCluster, kmeans::NaiveKMeans, arma::mat> km =KMeans(0);

  arma::Row<size_t> assignments; // Cluster assignments.
  arma::mat centroids; // Cluster centroids.

  km.Cluster(in_data,5,assignments, centroids); // 5 clusters.   

}

编译器错误消息为：

错误:没有可行的构造函数或推导指南来推导'HamerlyKMeans‘生成kmeans::HamerlyKMeans<度量的模板参数：：EuclideanDistance，arma::mat> ek = kmeans::HamerlyKMeans(in_data，EuclideanDistance())；build ^

构建/usr/include/mlpack/methods/kmeans/hamerly_kmeans.hpp:26:3:注意事项: MetricType = mlpack::metric::LMetric<2，true>，MatType = arma::Mat的候选函数不可行:第二个参数需要一个l值

build /usr/include/mlpack/methods/kmeans/hamerly_kmeans.hpp:19:7：(const MatType& dataset，MetricType& HamerlyKMeans )；build ^ build /usr/include/mlpack/methods/kmeans/hamerly_kmeans.hpp:19:7:注意:候选函数模板不可行:需要1个参数，但提供了2个build HamerlyKMeans HamerlyKMeans Build^

但是当我查看hamerly_kmeans.hpp时，我看到：

template<typename MetricType, typename MatType>
class HamerlyKMeans
{
 public:
  /**
   * Construct the HamerlyKMeans object, which must store several sets of
   * bounds.
   */
  HamerlyKMeans(const MatType& dataset, MetricType& metric);

我已经相当混乱了。我一点也不理解类的模板。想法？

Answer 1

我已经想通了。我将HamerlyKMeans类的结构更改为

  metric::EuclideanDistance euclid_distance;  

  kmeans::HamerlyKMeans< metric::EuclideanDistance, arma::mat> ek = 
    kmeans::HamerlyKMeans(in_data,euclid_distance);

我最好的理解是编译器告诉我第二个参数告诉我指标：：EuclidDistance()不构造l值(我认为它是一个变量，但上面的更改创建了变量euclid_distance，它是一个l值。上面的更改编译和链接都很好。