opencv目录及机器学习基础类

没想到，PCA竟然是位于opencv的core路径下面，与abs，add这样的功能函数并列放置。

1. Basic Structures

2.Basic C Structures and Operations

3.Dynamic Structures

4.core. The Core Functionality

Operations on Arrays

• PCA  Performs Principal Component Analysis of the supplied dataset.
  
• PCA::PCA
• PCA::operator ()
• PCA::project
• PCA::backProject

5. Drawing Functions

6.XML/YAML Persistence

7. XML/YAML Persistence (C API)

8. Clustering

kmeans

partition

9.Utility and System Functions and Macros

10.OpenGL interoperability

简介：通用类和函数

机器学习库（MLL）是一些用于分类、回归和数据聚类的类和函数。

大部分分类和回归算法是用C++类来实现。尽管这些算法有一些不同的特性（像处理missing measurements的能力，或者categorical input variables等），这些类之间有一些相同之处。这些相同之处在类 CvStatModel 中被定义，其他 ML 类都是从这个类中继承。

CvStatModel

ML库中的统计模型基类。

class CvStatModel
{
public:
    /* CvStatModel(); */
    /* CvStatModel( const CvMat* train_data ... ); */

    virtual ~CvStatModel();

    virtual void clear()=0;

    /* virtual bool train( const CvMat* train_data, [int tflag,] ..., const CvMat* responses, ...,
    [const CvMat* var_idx,] ..., [const CvMat* sample_idx,] ...
    [const CvMat* var_type,] ..., [const CvMat* missing_mask,] <misc_training_alg_params> ... )=0;
     */

    /* virtual float predict( const CvMat* sample ... ) const=0; */

    virtual void save( const char* filename, const char* name=0 )=0;
    virtual void load( const char* filename, const char* name=0 )=0;

    virtual void write( CvFileStorage* storage, const char* name )=0;
    virtual void read( CvFileStorage* storage, CvFileNode* node )=0;
};

CvSVM

支持矢量机

class CvSVM : public CvStatModel //继承自基类CvStatModel
{
public:
    // SVM type
    enum { C_SVC=100, NU_SVC=101, ONE_CLASS=102, EPS_SVR=103, NU_SVR=104 };//SVC是SVM分类器，SVR是SVM回归

    // SVM kernel type
    enum { LINEAR=0, POLY=1, RBF=2, SIGMOID=3 }; //提供四种核函数，分别是线性，多项式，径向基，sigmoid型函数。

    CvSVM();
    virtual ~CvSVM();

    CvSVM( const CvMat* _train_data, const CvMat* _responses,
           const CvMat* _var_idx=0, const CvMat* _sample_idx=0,
           CvSVMParams _params=CvSVMParams() );

    virtual bool train( const CvMat* _train_data, const CvMat* _responses,
                        const CvMat* _var_idx=0, const CvMat* _sample_idx=0,
                        CvSVMParams _params=CvSVMParams() );

    virtual float predict( const CvMat* _sample ) const;
    virtual int get_support_vector_count() const;
    virtual const float* get_support_vector(int i) const;
    virtual void clear();

    virtual void save( const char* filename, const char* name=0 );
    virtual void load( const char* filename, const char* name=0 );

    virtual void write( CvFileStorage* storage, const char* name );
    virtual void read( CvFileStorage* storage, CvFileNode* node );
    int get_var_count() const { return var_idx ? var_idx->cols : var_all; }

protected:
    ...
};

[ 编辑]

CvSVMParams

SVM训练参数struct

struct CvSVMParams
{
    CvSVMParams();
    CvSVMParams( int _svm_type, int _kernel_type,
                 double _degree, double _gamma, double _coef0,
                 double _C, double _nu, double _p,
                 CvMat* _class_weights, CvTermCriteria _term_crit );

    int         svm_type;
    int         kernel_type;
    double      degree; // for poly
    double      gamma;  // for poly/rbf/sigmoid
    double      coef0;  // for poly/sigmoid

    double      C;  // for CV_SVM_C_SVC, CV_SVM_EPS_SVR and CV_SVM_NU_SVR
    double      nu; // for CV_SVM_NU_SVC, CV_SVM_ONE_CLASS, and CV_SVM_NU_SVR
    double      p; // for CV_SVM_EPS_SVR
    CvMat*      class_weights; // for CV_SVM_C_SVC
    CvTermCriteria term_crit; // termination criteria
};