class TPoints3DABC: public TObject

 Add one 3D point defined by x,y,z to the array of the points
 as its last element

 Add one 3D point defined by x,y,z to the array of the points
 as its last element

 Compute distance from point px,py to an axis of the band defined.
  by pair points  (x1,y1),(x2,y2) where lineWidth is the width of the band

  Compute the closest distance of approach from point px,py to this line.
  The distance is computed in pixels units.


  Algorithm:

    A(x1,y1)         P                             B(x2,y2)

                     I
                     I
                     I
                     I
                    M(x,y)

  Let us call  a = distance AM     a2=a**2
               b = distance BM     b2=b**2
               c = distance AB     c2=c**2
               d = distance PM     d2=d**2
               u = distance AP     u2=u**2
               v = distance BP     v2=v**2     c = u + v

  d2 = a2 - u2
  d2 = b2 - v2  = b2 -(c-u)**2
     ==> u = (a2 -b2 +c2)/2c

   Float_t x1    = gPad->XtoAbsPixel(xp1);
   Float_t y1    = gPad->YtoAbsPixel(yp1);
   Float_t x2    = gPad->XtoAbsPixel(xp2);
   Float_t y2    = gPad->YtoAbsPixel(yp2);

 Add one 3D point defined by x,y,z to the array of the points
 as its last element

 GetN()  returns the number of allocated cells if any.
         GetN() > 0 shows how many cells
         can be available via GetP() method.
         GetN() == 0 then GetP() must return 0 as well

 GetP()  returns the pointer to the float point array
         of points if available
         The number of the available celss can be found via
         GetN() method.
         GetN() > 0 shows how many cells

 GetXYZ(Float_t *xyz,Int_t idx,Int_t num=1) fills the buffer supplied
 by the calling code with the points information.

  Input parameters:

   Float_t *xyz - an external user supplied floating point array.
   Int_t    num - the total number of the points to be copied
                  the dimension of that array the size of the
                  array is num*sizeof(Float_t) at least
   Int_t    idx - The index of the first copy to be taken.

  Return: The pointer to the buffer array supplied

 GetN()  returns the number of allocated cells if any.
         GetN() > 0 shows how many cells
         can be available via GetP() method.
         GetN() == 0 then GetP() must return 0 as well