// @(#)root/matrix:$Id$
// Authors: Fons Rademakers, Eddy Offermann   Nov 2003

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

#ifndef ROOT_TVectorT
#define ROOT_TVectorT

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// TVectorT                                                             //
//                                                                      //
// Template class of Vectors in the linear algebra package              //
//                                                                      //
//////////////////////////////////////////////////////////////////////////

#include "TMatrixT.h"
#include "TMatrixTSym.h"
#include "TMatrixTSparse.h"

#include <ROOT/RSpan.hxx>

template<class Element> class TVectorT : public TObject {

protected:
   Int_t    fNrows{0};             // number of rows
   Int_t    fRowLwb{0};            // lower bound of the row index
   Element *fElements{nullptr};    //[fNrows] elements themselves

   enum {kSizeMax = 5};            // size data container on stack, see New_m(),Delete_m()
   enum {kWorkMax = 100};          // size of work array's in several routines

   Element  fDataStack[kSizeMax];  ///<! data container
   Bool_t   fIsOwner{kTRUE};       ///<!default kTRUE, when Use array kFALSE

   Element* New_m   (Int_t size);
   void     Delete_m(Int_t size,Element*&);
   Int_t    Memcpy_m(Element *newp,const Element *oldp,Int_t copySize,
                     Int_t newSize,Int_t oldSize);

   void     Allocate(Int_t nrows,Int_t row_lwb = 0,Int_t init = 0);

   enum EVectorStatusBits {
     kStatus = BIT(14) // set if vector object is valid
   };

public:

   TVectorT() : fNrows(0), fRowLwb(0), fElements(nullptr), fDataStack (), fIsOwner(kTRUE) { }
   explicit TVectorT(Int_t n);
   TVectorT(Int_t lwb,Int_t upb);
   TVectorT(Int_t n,const Element *elements);
   TVectorT(Int_t lwb,Int_t upb,const Element *elements);
   TVectorT(const TVectorT            <Element> &another);
   TVectorT(const TMatrixTRow_const   <Element> &mr);
   TVectorT(const TMatrixTColumn_const<Element> &mc);
   TVectorT(const TMatrixTDiag_const  <Element> &md);
   template <class Element2> TVectorT(const TVectorT<Element2> &another)
   {
      R__ASSERT(another.IsValid());
      Allocate(another.GetUpb()-another.GetLwb()+1,another.GetLwb());
      *this = another;
   }
   TVectorT(Int_t lwb,Int_t upb,Double_t iv1, ...);
   ~TVectorT() override { TVectorT::Clear(); }

   inline          Int_t     GetLwb       () const { return fRowLwb; }
   inline          Int_t     GetUpb       () const { return fNrows+fRowLwb-1; }
   inline          Int_t     GetNrows     () const { return fNrows; }
   inline          Int_t     GetNoElements() const { return fNrows; }

   inline          Element  *GetMatrixArray  ()       { return fElements; }
   inline const    Element  *GetMatrixArray  () const { return fElements; }

   // For compatibility with STL classes
   inline          std::size_t size() const { return fNrows; }

   inline          Element  *data()       { return fElements; }
   inline const    Element  *data() const { return fElements; }

   // Implicit conversion of TVectorT to std::span, both non-const and const
   // version. Can be removed once the minimum C++ standard in C++20, because
   // then it's enough to implement the contiguous_range and sized_range
   // concepts. This should alredy be the case since data() and size() are
   // available.
   inline operator std::span<Element>()
   {
      return std::span<Element>{data(), size()};
   }
   inline operator std::span<const Element>() const
   {
      return std::span<const Element>{data(), size()};
   }

   inline void     Invalidate ()       { SetBit(kStatus); }
   inline void     MakeValid  ()       { ResetBit(kStatus); }
   inline Bool_t   IsValid    () const { return !TestBit(kStatus); }
   inline Bool_t   IsOwner    () const { return fIsOwner; }
   inline void     SetElements(const Element *elements) { R__ASSERT(IsValid());
                                                          memcpy(fElements,elements,fNrows*sizeof(Element)); }
   inline TVectorT<Element> &Shift     (Int_t row_shift)            { fRowLwb += row_shift; return *this; }
          TVectorT<Element> &ResizeTo  (Int_t lwb,Int_t upb);
   inline TVectorT<Element> &ResizeTo  (Int_t n)                    { return ResizeTo(0,n-1); }
   inline TVectorT<Element> &ResizeTo  (const TVectorT<Element> &v) { return ResizeTo(v.GetLwb(),v.GetUpb()); }

          TVectorT<Element> &Use       (Int_t lwb,Int_t upb,Element *data);
   const  TVectorT<Element> &Use       (Int_t lwb,Int_t upb,const Element *data) const
          { return (const TVectorT<Element>&)(const_cast<TVectorT<Element> *>(this))->Use(lwb,upb,const_cast<Element *>(data)); }
          TVectorT<Element> &Use       (Int_t n,Element *data);
   const  TVectorT<Element> &Use       (Int_t n,const Element *data) const ;
          TVectorT<Element> &Use       (TVectorT<Element> &v);
   const  TVectorT<Element> &Use       (const TVectorT<Element> &v) const ;

          TVectorT<Element> &GetSub    (Int_t row_lwb,Int_t row_upb,TVectorT<Element> &target,Option_t *option="S") const;
          TVectorT<Element>  GetSub    (Int_t row_lwb,Int_t row_upb,Option_t *option="S") const;
          TVectorT<Element> &SetSub    (Int_t row_lwb,const TVectorT<Element> &source);

   TVectorT<Element> &Zero();
   TVectorT<Element> &Abs ();
   TVectorT<Element> &Sqr ();
   TVectorT<Element> &Sqrt();
   TVectorT<Element> &Invert();
   TVectorT<Element> &SelectNonZeros(const TVectorT<Element> &select);

   Element Norm1   () const;
   Element Norm2Sqr() const;
   Element NormInf () const;
   Int_t   NonZeros() const;
   Element Sum     () const;
   Element Min     () const;
   Element Max     () const;

   inline const Element &operator()(Int_t index) const;
   inline       Element &operator()(Int_t index);
   inline const Element &operator[](Int_t index) const { return (*this)(index); }
   inline       Element &operator[](Int_t index)       { return (*this)(index); }

   TVectorT<Element> &operator= (const TVectorT                <Element> &source);
   TVectorT<Element> &operator= (const TMatrixTRow_const       <Element> &mr);
   TVectorT<Element> &operator= (const TMatrixTColumn_const    <Element> &mc);
   TVectorT<Element> &operator= (const TMatrixTDiag_const      <Element> &md);
   TVectorT<Element> &operator= (const TMatrixTSparseRow_const <Element> &md);
   TVectorT<Element> &operator= (const TMatrixTSparseDiag_const<Element> &md);
   template <class Element2> TVectorT<Element> &operator= (const TVectorT<Element2> &source)
   {
      if (!AreCompatible(*this,source)) {
         Error("operator=(const TVectorT2 &)","vectors not compatible");
         return *this;
      }

     TObject::operator=(source);
     const Element2 * const ps = source.GetMatrixArray();
           Element  * const pt = GetMatrixArray();
     for (Int_t i = 0; i < this->fNrows; i++)
        pt[i] = ps[i];
     return *this;
   }

   TVectorT<Element> &operator= (Element val);
   TVectorT<Element> &operator+=(Element val);
   TVectorT<Element> &operator-=(Element val);
   TVectorT<Element> &operator*=(Element val);

   TVectorT<Element> &operator+=(const TVectorT      <Element> &source);
   TVectorT<Element> &operator-=(const TVectorT      <Element> &source);
   TVectorT<Element> &operator*=(const TMatrixT      <Element> &a);
   TVectorT<Element> &operator*=(const TMatrixTSym   <Element> &a);
   TVectorT<Element> &operator*=(const TMatrixTSparse<Element> &a);

   Bool_t operator==(Element val) const;
   Bool_t operator!=(Element val) const;
   Bool_t operator< (Element val) const;
   Bool_t operator<=(Element val) const;
   Bool_t operator> (Element val) const;
   Bool_t operator>=(Element val) const;

   Bool_t MatchesNonZeroPattern(const TVectorT<Element> &select);
   Bool_t SomePositive         (const TVectorT<Element> &select);
   void   AddSomeConstant      (Element val,const TVectorT<Element> &select);

   void   Randomize            (Element alpha,Element beta,Double_t &seed);

   TVectorT<Element> &Apply(const TElementActionT   <Element> &action);
   TVectorT<Element> &Apply(const TElementPosActionT<Element> &action);

   void Add(const TVectorT<Element> &v);
   void Add(const TVectorT<Element> &v1, const TVectorT<Element> &v2);
   void Clear(Option_t * /*option*/ = "") override
   {
      if (fIsOwner)
         Delete_m(fNrows, fElements);
      else
         fElements = nullptr;
      fNrows = 0;
   }
   void Draw(Option_t *option = "") override;       // *MENU*
   void Print(Option_t *option = "") const override;  // *MENU*

   ClassDefOverride(TVectorT,4)  // Template of Vector class
};

// When building with -fmodules, it instantiates all pending instantiations,
// instead of delaying them until the end of the translation unit.
// We 'got away with' probably because the use and the definition of the
// explicit specialization do not occur in the same TU.
//
// In case we are building with -fmodules, we need to forward declare the
// specialization in order to compile the dictionary G__Matrix.cxx.
template <> TClass *TVectorT<double>::Class();

template<class Element> inline       TVectorT<Element> &TVectorT<Element>::Use     (Int_t n,Element *data) { return Use(0,n-1,data); }
template<class Element> inline const TVectorT<Element> &TVectorT<Element>::Use     (Int_t n,const Element *data) const { return Use(0,n-1,data); }
template<class Element> inline       TVectorT<Element> &TVectorT<Element>::Use     (TVectorT &v)
                                                                                   {
                                                                                     R__ASSERT(v.IsValid());
                                                                                     return Use(v.GetLwb(),v.GetUpb(),v.GetMatrixArray());
                                                                                   }
template<class Element> inline const TVectorT<Element> &TVectorT<Element>::Use     (const TVectorT &v) const
                                                                                   {
                                                                                     R__ASSERT(v.IsValid());
                                                                                     return Use(v.GetLwb(),v.GetUpb(),v.GetMatrixArray());
                                                                                   }
template<class Element> inline       TVectorT<Element>  TVectorT<Element>::GetSub  (Int_t row_lwb,Int_t row_upb,Option_t *option) const
                                                                                   {
                                                                                     TVectorT tmp;
                                                                                     this->GetSub(row_lwb,row_upb,tmp,option);
                                                                                     return tmp;
                                                                                   }

template<class Element> inline const Element &TVectorT<Element>::operator()(Int_t ind) const
{
   // Access a vector element.

   R__ASSERT(IsValid());
   const Int_t aind = ind-fRowLwb;
   if (aind >= fNrows || aind < 0) {
      Error("operator()","Request index(%d) outside vector range of %d - %d",ind,fRowLwb,fRowLwb+fNrows);
      return TMatrixTBase<Element>::NaNValue();
   }

   return fElements[aind];
}
template<class Element> inline Element &TVectorT<Element>::operator()(Int_t ind)
{
   // Access a vector element.

   R__ASSERT(IsValid());
   const Int_t aind = ind-fRowLwb;
   if (aind >= fNrows || aind < 0) {
      Error("operator()","Request index(%d) outside vector range of %d - %d",ind,fRowLwb,fRowLwb+fNrows);
      return TMatrixTBase<Element>::NaNValue();
   }

   return fElements[aind];
}
inline namespace TMatrixTAutoloadOps {

template<class Element> Bool_t              operator==  (const TVectorT      <Element>  &source1,const TVectorT <Element>  &source2);
template<class Element> TVectorT<Element>   operator+   (const TVectorT      <Element>  &source1,const TVectorT <Element>  &source2);
template<class Element> TVectorT<Element>   operator-   (const TVectorT      <Element>  &source1,const TVectorT <Element>  &source2);
template<class Element> Element             operator*   (const TVectorT      <Element>  &source1,const TVectorT <Element>  &source2);
template<class Element> TVectorT<Element>   operator*   (const TMatrixT      <Element>  &a,      const TVectorT <Element>  &source);
template<class Element> TVectorT<Element>   operator*   (const TMatrixTSym   <Element>  &a,      const TVectorT <Element>  &source);
template<class Element> TVectorT<Element>   operator*   (const TMatrixTSparse<Element>  &a,      const TVectorT <Element>  &source);
template<class Element> TVectorT<Element>   operator*   (      Element                   val,    const TVectorT <Element>  &source);
template<class Element>
inline
TVectorT<Element> operator*   (const TVectorT <Element>  &source, Element val) { return val * source; }

template<class Element> Element             Dot         (const TVectorT      <Element>  &source1,const TVectorT <Element>  &source2);
template <class Element1,class Element2>
                        TMatrixT<Element1>  OuterProduct(const TVectorT      <Element1> &v1,     const TVectorT <Element2> &v2);
template <class Element1,class Element2,class Element3>
                        TMatrixT<Element1> &OuterProduct(      TMatrixT      <Element1> &target, const TVectorT <Element2> &v1,     const TVectorT      <Element3> &v2);
template <class Element1,class Element2,class Element3>
                        Element1            Mult        (const TVectorT      <Element1> &v1,     const TMatrixT <Element2> &m,      const TVectorT      <Element3> &v2);

template<class Element> TVectorT<Element>  &Add         (      TVectorT      <Element>  &target,       Element              scalar, const TVectorT      <Element>  &source);
template<class Element> TVectorT<Element>  &Add         (      TVectorT      <Element>  &target,       Element              scalar, const TMatrixT      <Element>  &a,
                                                         const TVectorT<Element> &source);
template<class Element> TVectorT<Element>  &Add         (      TVectorT      <Element>  &target,       Element              scalar, const TMatrixTSym   <Element>  &a,
                                                         const TVectorT<Element> &source);
template<class Element> TVectorT<Element>  &Add         (      TVectorT      <Element>  &target,       Element              scalar, const TMatrixTSparse<Element>  &a,
                                                         const TVectorT<Element> &source);
template<class Element> TVectorT<Element>  &AddElemMult (      TVectorT      <Element>  &target,       Element              scalar, const TVectorT      <Element>  &source1,
                                                         const TVectorT      <Element>  &source2);
template<class Element> TVectorT<Element>  &AddElemMult (      TVectorT      <Element>  &target,       Element              scalar, const TVectorT      <Element>  &source1,
                                                         const TVectorT      <Element>  &source2,const TVectorT <Element>  &select);
template<class Element> TVectorT<Element>  &AddElemDiv  (      TVectorT      <Element>  &target,       Element              scalar, const TVectorT      <Element>  &source1,
                                                         const TVectorT      <Element>  &source2);
template<class Element> TVectorT<Element>  &AddElemDiv  (      TVectorT      <Element>  &target,       Element              scalar, const TVectorT      <Element>  &source1,
                                                         const TVectorT      <Element>  &source2,const TVectorT <Element>  &select);
template<class Element> TVectorT<Element>  &ElementMult (      TVectorT      <Element>  &target, const TVectorT <Element>  &source);
template<class Element> TVectorT<Element>  &ElementMult (      TVectorT      <Element>  &target, const TVectorT <Element>  &source, const TVectorT      <Element>  &select);
template<class Element> TVectorT<Element>  &ElementDiv  (      TVectorT      <Element>  &target, const TVectorT <Element>  &source);
template<class Element> TVectorT<Element>  &ElementDiv  (      TVectorT      <Element>  &target, const TVectorT <Element>  &source, const TVectorT      <Element>  &select);

template<class Element1,class Element2> Bool_t AreCompatible(const TVectorT<Element1> &v1,const TVectorT<Element2> &v2,Int_t verbose=0);
// Check matrix and vector for compatibility in multiply:  M * v and v * M
template<class Element1,class Element2> Bool_t AreCompatible(const TMatrixT<Element1> &m, const TVectorT<Element2> &v, Int_t verbose=0);
template<class Element1,class Element2> Bool_t AreCompatible(const TVectorT<Element1> &v, const TMatrixT<Element2> &m, Int_t verbose=0);

template<class Element> void   Compare              (const TVectorT <Element>  &source1,const TVectorT <Element>  &source2);
template<class Element> Bool_t VerifyVectorValue    (const TVectorT <Element>  &m,            Element val,Int_t verbose, Element maxDevAllow);
template<class Element> Bool_t VerifyVectorValue    (const TVectorT <Element>  &m,            Element val,Int_t verbose)
                                                     { return VerifyVectorValue(m,val,verbose,Element(0.0)); }
template<class Element> Bool_t VerifyVectorValue    (const TVectorT <Element>  &m,            Element val)
                                                     { return VerifyVectorValue(m,val,1,Element(0.0)); }
template<class Element> Bool_t VerifyVectorIdentity (const TVectorT <Element>  &m1,const TVectorT <Element> &m2, Int_t verbose, Element maxDevAllow);
template<class Element> Bool_t VerifyVectorIdentity (const TVectorT <Element>  &m1,const TVectorT <Element> &m2, Int_t verbose)
                                                     { return VerifyVectorIdentity(m1,m2,verbose,Element(0.0)); }
template<class Element> Bool_t VerifyVectorIdentity (const TVectorT <Element>  &m1,const TVectorT <Element> &m2)
                                                     { return VerifyVectorIdentity(m1,m2,1,Element(0.0)); }
} // inline namespace TMatrixTAutoloadOps
#endif