class THealPix: public TNamed, public TAttLine, public TAttFill, public TAttMarker

 Destructor

 Performs the operation: this = this + c1*hp1
 if errors are defined (see THealPix::Sumw2), errors are also recalculated.
 Note that if h1 has Sumw2 set, Sumw2 is automatically called for this
 if not already set.

 SPECIAL CASE (Average/Efficiency HEALPixs)
 For HEALPixs representing averages or efficiencies, one should compute the
 average of the two HEALPixs and not the sum. One can mark a histogram to be
 an average HEALPix by setting its bit kIsAverage with
    myhp.SetBit(THealPix::kIsAverage);
 Note that the two HELAPixs must have their kIsAverage bit set

 IMPORTANT NOTE1: If you intend to use the errors of this HEALPix later
 you should call Sumw2 before making this operation.
 This is particularly important if you fit the histogram after THealPix::Add

 IMPORTANT NOTE2: if hp1 has a normalisation factor, the normalisation
 factor is used, ie this = this + c1*factor*hp1
 Use the other THealPix::Add function if you do not want this feature

 Replace contents of this HEALPix by the addition of hp1 and hp2

   this = c1*hp1 + c2*hp2
 if errors are defined (see THealPix::Sumw2), errors are also recalculated
 Note that if hp1 or hp2 have Sumw2 set, Sumw2 is automatically called for
 this if not already set.

 SPECIAL CASE (Average/Efficiency HEALPixs)
 For HEALPixs representing averages or efficiencies, one should compute the
 average of the two HEALPixs and not the sum. One can mark a HEALPix to be
 an average HEALPix by setting its bit kIsAverage with
    myhp.SetBit(THealPix::kIsAverage);
 Note that the two HEALPixs must have their kIsAverage bit set

 IMPORTANT NOTE: If you intend to use the errors of this HEALPix later
 you should call Sumw2 before making this operation.
 This is particularly important if you fit the HEALPix after THealPix::Add

 Increment bin content by 1

 Incremetn bin content by a weight w

 Stes the flag controlling the automatic add of HEALPix in memory

 By default (fAddDirectory = kTRUE), HEALPixs are automatically added to the
 list of objects in memory.
 Note that one HEALPix can be removed from its support directory by calling
 hp->SetDirectory(0) or hp->SetDirectory(dir) to add it to the list of
 objects in the directory dir.

 NOTE that this is a static function. To call it, use;
 THealPix::AddDirectory

 Creates HEALPix basic data structure

 Copy this HEALPix structure to obj

 Note that this function does not copy the list of associated functions.
 Use TObJect::Clone to make a full copy of a HEALPix

 Divide this HEALPix by hp1

 this = this/hp1
 If errors are defined (see THealPix::Sumw2), errors are also recalculated.
 Note that if hp1 has Sumw2 set, Sumw2 is automatically called for this
 if not already set.
 The resulting errors are calculated assuming uncorrelated HEALPixs.
 See the other THealPix::Divide that gives the possibility to optionaly
 compute Binomial errors.

 IMPORTANT NOTE: If you intend to use the errors of this HEALPix later
 you should call Sumw2 before making this operation.
 This is particularly important if you fit the HEALPix after THealPix::Scale

 Increments bin with polar coordinates by 1.

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Increments bin with polar coordinates with a weight w.

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Increments bin with cartesian coordinates by 1.

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Increments bin with cartesian coordinates with a weight w

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Increments bin with cartesian coordinates by 1.

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Increments bin with cartesian coordinates with a weight w

 If the storage of the sum of squares of weights has been triggered,
 via the function Sumw2, then the sum of the sqaures of weights is
 incremented by w^2 in the bin.

 Return the bin number corresponds to (theta, phi).

 Oribinal code is Healpix_Base::ang2pix_z_phi of HEALPix C++

 Return the average of all bin contents.

 Return the solid angle of each bin. If degree2 == kTRUE, return value is
 in unit of degree.

 Return the coordinates of bin center. If the default unit is set to degre
 via THealPix::SetDegree, theta and phi are given in unit of degree.

 Oribinal code is Healpix_Base::pix2ang of HEALPix C++
 See Gorski et al. ApJ 622 (2005) for equation numbering

 Get the content of a bin.

 Return the coordinates of four or five vertices of each bin. Their unit
 is always degree. The return value is the number of vertices. Five vertices
 are given to only eight polar bins.

 static function
 return kTRUE if THealPix::Sumw2 must be called when creating new HEALPix.
 see THealPix::SetDefaultSumw2.

 Return the current number of entries

 Return the sum of weights

 Draw this HEALPix with options

 HEALPixs are drawn via the THealPainter class. Each HEALPix has a pointer
 to its own painter (to be usable in a mutithreaded program). The same
 HEALPix can be drawn with different options in different pads. When a
 HEALPix drawn in a pad is deleted, the HEALPix is automatically removed
 from the pad or pads where it was drawn.

 If a HEALPix is drawn in a pad, then filled again, the new status of the
 HEALPix will be automatically shown in the pad next time the pad is
 updated. One does not need to redraw the HEALPix.

 To draw the current version of a HEALPix in a pad, one can use
    hp->DrawCopy();
 This make a clone of the HEALPix. Once the clone is drawn, the original
 HEALPix may be modified or deleted without affecting the aspect of the
 clone.

 By default, THealPix::Draw clears the current pad.

 One can use THealPix::SetMaximum and THealPix::SetMinimum to force a
 particular value for the maximum or the minimum scale on the plot.

 THealPix::UseCurrentStyle can be used to change all HEALPix graphics
 attributes to correspond to the current selected style. This function
 must be called for each HEALPix.

 In case of reads and draws many HEALPixs from a file, one can force the
 HEALPixs to inherit automatically the current graphic style by calling
 before gROOT->ForceStyle();

 See THealPainter::Paint for a description of all the drawing options.

 Copy this HEALPix and Draw in the current pad.

 Once the HEALPix is drawn into the pad, any further modification
 using graphics input will be made on the copy of the HEALPix,
 and not to the original object.

 See Draw for the list of options

 Control routine to paint any kind of HEALPixs

 Read the header of a FITS file. If success, return kTRUE.

 Rebin this HEALPix to new order.

 If a new name is given, return value is a pointer to new object. Otherwise
 this object will be rebined.

 Rebinning to higher resolution does not do any interpolation nor smoothing.
 It does only dividing the bin contents.

 Set the contents of a bin

 static function.
 When this static function is called with sumw2=kTRUE, all new
 HEALPix will automatically activate the storage of
 the sum of squares of errors, ie THealPix::Sumw2 is automatically called.

 Set the order of a HEALPix. Do NOT call this function when you want to
 rebin the HEALPix. Use THealPix::Rebin instead.

 Set the unit of HEALPix. This value is used in saving to FITS format.

 Stream a class object.

 Create structure to store sum of squares of weights*-*-*-*-*-*-*-*

     if HEALPix is already filled, the sum of squares of weights
     is filled with the existing bin contents

     The error per bin will be computed as sqrt(sum of squares of weight)
     for each bin.

  This function is automatically called when the HEALPix is created
  if the static function THealPix::SetDefaultSumw2 has been called before.

 Copy current attributes from/to current style.

   -*-*-*-*-*Return value of error associated to bin number bin*-*-*-*-*


    if the sum of squares of weights has been defined (via Sumw2),
    this function returns the sqrt(sum of w2).
    otherwise it returns the sqrt(contents) for this bin.

   -*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

  Return contour values into array levels if pointer levels is non zero

  The function returns the number of contour levels.
  see GetContourLevel to return one contour only

 Return value of contour number level
 see GetContour to return the array of all contour levels

 Return the value of contour number "level" in Pad coordinates ie: if the
 Pad is in log scale along Z it returns le log of the contour level value.
 see GetContour to return the array of all contour levels

 Retrun maximum value smaller than maxval of bins.

 Return location of bin with maximum value.

 Retrun minimum value smaller than maxval of bins.

 Return location of bin with minimum value.

 Return number of rows used in FITS storaging.

 return pointer to patiner
 if painter does not exist, it is created

 Return ordering sheme as string.
 R

 return a pointer to the X axis object

 return a pointer to the Y axis object

 return a pointer to the Z axis object

 Multiply this histogram by a constant c1

 this = c1*this

 Note that both contents and errors (if any) are scaled.
 This function uses the services of THealPix::Add

 IMPORTANT NOTE: If you intend to use the errors of this HEALPix later
 you should call Sumw2 before making this operation.
 This is particularly important if you fit the histogram after
 THealPix::Scale

 One can scale a HEALPix such that the bins integral is equal to
 the normalization parameter via THealPix::Scale(Double_t norm), where norm
 is the desired normalization divided by the integral of the histogram.

 If option contains "width" the bin contents and errors are divided
 by the bin width.

 see convention for numbering bins in THealPix::GetBin

 Redifine the number of bins. Do NOT call this method.

   -*-*-*-*-*-*Set the number and values of contour levels*-*-*-*-*-*-*-*-*


  By default the number of contour levels is set to 20.

  if argument levels = 0 or missing, equidistant contours are computed

   -*-*-*-*-*-*-*-*-*Set value for one contour level*-*-*-*-*-*-*-*-*-*-*-*

 By default when a HEALPix is created, it is added to the list
 of HEALPix objects in the current directory in memory.
 Remove reference to this HEALPix from current directory and add
 reference to new directory dir. dir can be 0 in which case the
 HEALPix does not belong to any directory.

 Set the maximum value for the Z axis.

 By default the maximum value is automatically set to the maximum bin
 content plus a margin of 10 per cent.
 Use THealPix::GetMaximum to find the maximum value of a HEALPix.
 Use THealPix::GetMaximumBin to find the bin with the maximum value of
 a HEALPix.

 Set the minimum value for the Z axis.

 By default the minimum value is automatically set to zero if all bin
 contents are positive or the minimum - 10 per cen otherwise.
 Use THealPix::GetMinimum to find the minimum value of a HEALPix.
 Use THealPix::GetMinimumBin to find the bin with the minimum value of
 a HEALPix.

 Change the name of this HEALPix.

 Change the name and title of this HEALPix.

 Original code is Healpix_Base::ring2xyf of HEALPix C++

 Original code is Healpix_Base::xyf2ring of HEALPix C++