tnt_vec.h

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/*
*
* Template Numerical Toolkit (TNT)
*
* Mathematical and Computational Sciences Division
* National Institute of Technology,
* Gaithersburg, MD USA
*
*
* This software was developed at the National Institute of Standards and
* Technology (NIST) by employees of the Federal Government in the course
* of their official duties. Pursuant to title 17 Section 105 of the
* United States Code, this software is not subject to copyright protection
* and is in the public domain. NIST assumes no responsibility whatsoever for
* its use by other parties, and makes no guarantees, expressed or implied,
* about its quality, reliability, or any other characteristic.
*
*/
 
 
 
#ifndef TNT_VEC_H
#define TNT_VEC_H
 
#include "tnt_subscript.h"
#include <cstdlib>
#include <cassert>
#include <iostream>
#include <sstream>
 
namespace TNT
{
 
template <class T>
class Vector 
{
 
 
  public:
 
    typedef Subscript   size_type;
    typedef         T   value_type;
    typedef         T   element_type;
    typedef         T*  pointer;
    typedef         T*  iterator;
    typedef         T&  reference;
    typedef const   T*  const_iterator;
    typedef const   T&  const_reference;
 
    Subscript lbound() const { return 1;}
 
  protected:
    T* v_;                  
    T* vm1_;        // pointer adjustment for optimzied 1-offset indexing
    Subscript n_;
 
    // internal helper function to create the array
    // of row pointers
 
    void initialize(Subscript N)
    {
        // adjust pointers so that they are 1-offset:
        // v_[] is the internal contiguous array, it is still 0-offset
        //
        assert(v_ == NULL);
        v_ = new T[N];
        assert(v_  != NULL);
        vm1_ = v_-1;
        n_ = N;
    }
   
    void copy(const T*  v)
    {
        Subscript N = n_;
        Subscript i;
 
#ifdef TNT_UNROLL_LOOPS
        Subscript Nmod4 = N & 3;
        Subscript N4 = N - Nmod4;
 
        for (i=0; i<N4; i+=4)
        {
            v_[i] = v[i];
            v_[i+1] = v[i+1];
            v_[i+2] = v[i+2];
            v_[i+3] = v[i+3];
        }
 
        for (i=N4; i< N; i++)
            v_[i] = v[i];
#else
 
        for (i=0; i< N; i++)
            v_[i] = v[i];
#endif      
    }
 
    void set(const T& val)
    {
        Subscript N = n_;
        Subscript i;
 
#ifdef TNT_UNROLL_LOOPS
        Subscript Nmod4 = N & 3;
        Subscript N4 = N - Nmod4;
 
        for (i=0; i<N4; i+=4)
        {
            v_[i] = val;
            v_[i+1] = val;
            v_[i+2] = val;
            v_[i+3] = val; 
        }
 
        for (i=N4; i< N; i++)
            v_[i] = val;
#else
 
        for (i=0; i< N; i++)
            v_[i] = val;
        
#endif      
    }
    
 
 
    void destroy()
    {     
        /* do nothing, if no memory has been previously allocated */
        if (v_ == NULL) return ;
 
        /* if we are here, then matrix was previously allocated */
        delete [] (v_);     
 
        v_ = NULL;
        vm1_ = NULL;
    }
 
 
  public:
 
    // access
 
    iterator begin() { return v_;}
    iterator end()   { return v_ + n_; }
    const iterator begin() const { return v_;}
    const iterator end() const  { return v_ + n_; }
 
    // destructor
 
    ~Vector() 
    {
        destroy();
    }
 
    // constructors
 
    Vector() : v_(0), vm1_(0), n_(0)  {};
 
    Vector(const Vector<T> &A) : v_(0), vm1_(0), n_(0)
    {
        initialize(A.n_);
        copy(A.v_);
    }
 
    Vector(Subscript N, const T& value = T()) :  v_(0), vm1_(0), n_(0)
    {
        initialize(N);
        set(value);
    }
 
    Vector(Subscript N, const T* v) :  v_(0), vm1_(0), n_(0)
    {
        initialize(N);
        copy(v);
    }
 
    Vector(Subscript N, char *s) :  v_(0), vm1_(0), n_(0)
    {
        initialize(N);
        std::istringstream ins(s);
 
        Subscript i;
 
        for (i=0; i<N; i++)
                ins >> v_[i];
    }
 
 
    // methods
    // 
    Vector<T>& newsize(Subscript N)
    {
        if (n_ == N) return *this;
 
        destroy();
        initialize(N);
 
        return *this;
    }
 
 
    // assignments
    //
    Vector<T>& operator=(const Vector<T> &A)
    {
        if (v_ == A.v_)
            return *this;
 
        if (n_ == A.n_)         // no need to re-alloc
            copy(A.v_);
 
        else
        {
            destroy();
            initialize(A.n_);
            copy(A.v_);
        }
 
        return *this;
    }
        
    Vector<T>& operator=(const T& scalar)
    { 
        set(scalar);  
        return *this;
    }
 
    inline Subscript dim() const 
    {
        return  n_; 
    }
 
    inline Subscript size() const 
    {
        return  n_; 
    }
 
 
    inline reference operator()(Subscript i)
    { 
#ifdef TNT_BOUNDS_CHECK
        assert(1<=i);
        assert(i <= n_) ;
#endif
        return vm1_[i]; 
    }
 
    inline const_reference operator() (Subscript i) const
    {
#ifdef TNT_BOUNDS_CHECK
        assert(1<=i);
        assert(i <= n_) ;
#endif
        return vm1_[i]; 
    }
 
    inline reference operator[](Subscript i)
    { 
#ifdef TNT_BOUNDS_CHECK
        assert(0<=i);
        assert(i < n_) ;
#endif
        return v_[i]; 
    }
 
    inline const_reference operator[](Subscript i) const
    {
#ifdef TNT_BOUNDS_CHECK
        assert(0<=i);
 
 
 
 
 
 
        assert(i < n_) ;
#endif
        return v_[i]; 
    }
 
 
 
};
 
 
/* ***************************  I/O  ********************************/
 
template <class T>
std::ostream& operator<<(std::ostream &s, const Vector<T> &A)
{
    Subscript N=A.dim();
 
    s <<  N << "\n";
 
    for (Subscript i=0; i<N; i++)
        s   << A[i] << " " << "\n";
    s << "\n";
 
    return s;
}
 
template <class T>
std::istream & operator>>(std::istream &s, Vector<T> &A)
{
 
    Subscript N;
 
    s >> N;
 
    if ( !(N == A.size() ))
    {
        A.newsize(N);
    }
 
 
    for (Subscript i=0; i<N; i++)
            s >>  A[i];
 
 
    return s;
}
 
// *******************[ basic matrix algorithms ]***************************
 
 
template <class T>
Vector<T> operator+(const Vector<T> &A, 
    const Vector<T> &B)
{
    Subscript N = A.dim();
 
    assert(N==B.dim());
 
    Vector<T> tmp(N);
    Subscript i;
 
    for (i=0; i<N; i++)
            tmp[i] = A[i] + B[i];
 
    return tmp;
}
 
template <class T>
Vector<T> operator-(const Vector<T> &A, 
    const Vector<T> &B)
{
    Subscript N = A.dim();
 
    assert(N==B.dim());
 
    Vector<T> tmp(N);
    Subscript i;
 
    for (i=0; i<N; i++)
            tmp[i] = A[i] - B[i];
 
    return tmp;
}
 
template <class T>
Vector<T> operator*(const Vector<T> &A, 
    const Vector<T> &B)
{
    Subscript N = A.dim();
 
    assert(N==B.dim());
 
    Vector<T> tmp(N);
    Subscript i;
 
    for (i=0; i<N; i++)
            tmp[i] = A[i] * B[i];
 
    return tmp;
}
 
 
template <class T>
T dot_prod(const Vector<T> &A, const Vector<T> &B)
{
    Subscript N = A.dim();
    assert(N == B.dim());
 
    Subscript i;
    T sum = 0;
 
    for (i=0; i<N; i++)
        sum += A[i] * B[i];
 
    return sum;
}
 
}   /* namespace TNT */
 
#endif
// TNT_VEC_H