TPrincipal.
The user interface is in TTree::Principal that calls the TTreePlayer::Principal
function. The specs of this interface are:
TPrincipal *TTree::Principal(const char *varexp, const char *selection, Option_t *option, Int_t nentries, Int_t firstentry)
{
//*-*-*-*-*-*-*-*-*Interface to the Principal Components Analysis class*-*-*
//*-*              ====================================================
//
//   Create an instance of TPrincipal
//   Fill it with the selected variables
//   if option "n" is specified, the TPrincipal object is filled with
//                 normalized variables.
//   If option "p" is specified, compute the principal components
//   If option "p" and "d" print results of analysis
//   If option "p" and "h" generate standard histograms
//   If option "p" and "c" generate code of conversion functions
//   return a pointer to the TPrincipal object. It is the user responsability
//   to delete this object.
//   The option default value is "np"
//
//   see TTree::Draw for explanation of the other parameters.
//
//   The created object is  named "principal" and a reference to it
//   is added to the list of specials Root objects.
//   you can retrieve a pointer to the created object via:
//      TPrincipal *principal =
//        (TPrincipal*)gROOT->GetListOfSpecials()->FindObject("principal");
//


git-svn-id: http://root.cern.ch/svn/root/trunk@489 27541ba8-7e3a-0410-8455-c3a389f83636

In the constructor, the TPrincipal object, named "principal" by default
is automatically added the gROOT->GetListOfSpecials().


git-svn-id: http://root.cern.ch/svn/root/trunk@488 27541ba8-7e3a-0410-8455-c3a389f83636

side effects. A simple session opening a root file will crash when
the TROOT destructor is called. This line recommented.


git-svn-id: http://root.cern.ch/svn/root/trunk@487 27541ba8-7e3a-0410-8455-c3a389f83636

must be cast to a void explicitly in the TF1 constructor:
   char *funcname = G__p2f2funcname((void*)fcn);


git-svn-id: http://root.cern.ch/svn/root/trunk@486 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@485 27541ba8-7e3a-0410-8455-c3a389f83636

   SafeDelete(fInterpreter);
This sattement was disabled because of a crash in CINT destructors.
This problem seems to be fixed with teh new version of CINT.
The reason for activating it, is that cint opens files (like bool.h) that
it closes only when explicitly told (by scratch_all and G__close_inputfiles).
Currently neither is being called at  the end of a ROOT process so a few
files are left open


git-svn-id: http://root.cern.ch/svn/root/trunk@484 27541ba8-7e3a-0410-8455-c3a389f83636

of the convention used for font types, size and quality.


git-svn-id: http://root.cern.ch/svn/root/trunk@483 27541ba8-7e3a-0410-8455-c3a389f83636

must be taken into account.


git-svn-id: http://root.cern.ch/svn/root/trunk@482 27541ba8-7e3a-0410-8455-c3a389f83636

function from an interpreted code.


git-svn-id: http://root.cern.ch/svn/root/trunk@481 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@480 27541ba8-7e3a-0410-8455-c3a389f83636

I have source of ROOT 2.23 and made a small fix in META_Class.cxx
line 270

OLD   if(realDataObject != gROOT) {

NEW   if(realDataObject && realDataObject != gROOT) {

This prevents browser segv when you click on class name.


git-svn-id: http://root.cern.ch/svn/root/trunk@479 27541ba8-7e3a-0410-8455-c3a389f83636

Replace the name of the static variables in the generated code by
names starting by g rather thab fg


git-svn-id: http://root.cern.ch/svn/root/trunk@478 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@477 27541ba8-7e3a-0410-8455-c3a389f83636

being they not used in ProcessLine() yet.


git-svn-id: http://root.cern.ch/svn/root/trunk@476 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@475 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@474 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@473 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@472 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@471 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@470 27541ba8-7e3a-0410-8455-c3a389f83636

  Char_t* prefix   = (isMethod ? Form("%s::", classname) : "");
  Char_t* cv_qual  = (isMethod ? "" : "static ");
by
  const Char_t* prefix   = (isMethod ? Form("%s::", classname) : "");
  const Char_t* cv_qual  = (isMethod ? "" : "static ");


git-svn-id: http://root.cern.ch/svn/root/trunk@469 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@468 27541ba8-7e3a-0410-8455-c3a389f83636

The Sun compiler was complaining.


git-svn-id: http://root.cern.ch/svn/root/trunk@467 27541ba8-7e3a-0410-8455-c3a389f83636

errors or warnings on some machines.
These functions are empty for the time being.


git-svn-id: http://root.cern.ch/svn/root/trunk@466 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@465 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@464 27541ba8-7e3a-0410-8455-c3a389f83636

#include <fstream>
#include <iostream>
#include <iomanip>
by
#include <fstream.h>
#include <iostream.h>
#include <iomanip.h>


git-svn-id: http://root.cern.ch/svn/root/trunk@463 27541ba8-7e3a-0410-8455-c3a389f83636

the dimension was not a constant expression.


git-svn-id: http://root.cern.ch/svn/root/trunk@462 27541ba8-7e3a-0410-8455-c3a389f83636

errors or warnings on some machines.
These functions are empty for the time being.


git-svn-id: http://root.cern.ch/svn/root/trunk@461 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@460 27541ba8-7e3a-0410-8455-c3a389f83636

The Principal Components Analysis class
=======================================
In many applications of various fields of research, the treatment of
large amounts of data requires powerful techniques capable of rapid
data reduction and analysis. Usually, the quantities most
conveniently measured by the experimentalist, are not necessarily the
most significant for classification and analysis of the data. It is
then useful to have a way of selecting an optimal set of variables
necessary for the recognition process and reducing the dimensionality
of the problem, resulting in an easier classification procedure.

TPrincipal is the implementation of one such method of
feature selection, namely the principal components analysis.
This multidimensional technique is well known in the field of pattern
recognition and and its use in Particle Physics has been documented
elsewhere (cf. H. Wind, <I>Function Parameterization</I>, CERN
72-21).


git-svn-id: http://root.cern.ch/svn/root/trunk@459 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@458 27541ba8-7e3a-0410-8455-c3a389f83636

the changes in THistpainter::paintContour.


git-svn-id: http://root.cern.ch/svn/root/trunk@457 27541ba8-7e3a-0410-8455-c3a389f83636

implementation header.
Add new member functions to add, multiply or divide an histogram
with a function:
    virtual void     Add(TF1 *h1, Double_t c1=1);
    virtual void     Divide(TF1 *h1, Double_t c1=1);
    virtual void     Multiply(TF1 *h1, Double_t c1=1);


git-svn-id: http://root.cern.ch/svn/root/trunk@456 27541ba8-7e3a-0410-8455-c3a389f83636

with a function:
    virtual void     Add(TF1 *h1, Double_t c1=1);
    virtual void     Divide(TF1 *h1, Double_t c1=1);
    virtual void     Multiply(TF1 *h1, Double_t c1=1);


git-svn-id: http://root.cern.ch/svn/root/trunk@455 27541ba8-7e3a-0410-8455-c3a389f83636

This new option is used by THistPainter::PaintContour to generate
a list of TGraph objects corresponding to the points for each contour.


git-svn-id: http://root.cern.ch/svn/root/trunk@454 27541ba8-7e3a-0410-8455-c3a389f83636

  lines go to the marker without a gap.

- New options to draw contours for 2-d histograms.
  The contour option "CONT" is now a pure 2-D option. It is not based
  on the surface/lego algorithms.
  This option computes now a set of points stored in a list of TGraph objects.
  The points in the TGraph are sorted, such that one contour can be drawn
  with one fill area. In addition, when the option "List" is specified,
  the list of generated TGraph objects is stored in a TObjArray with the
  name "contours". This TObjArray is accessible via gROOT->GetListOfSpecials().
  When the option "CONT" is used, one can superimpose new contours on top
  using the options "CONT1", "CONT2" or "CONT3".
  The previous algorithm used by the option "CONT" is still available
  as option "CONT4".
  For example, the following call
     h2->Draw("contzlist");
  produces:
    - a picture with surface colors to delimitate each contour
    - the color palette.
    - a list of the boundary points for each countour.
  The points used to draw the contours are saved in the TGraph format
  and are accessible in the following way:
  TObjArray *contours =
           gROOT->GetListOfSpecials()->FindObject("contours")
  Int_t ncontours = contours->GetSize();
  TList *list = (TList*)contours->At(i); //where i is a contour number
  list contains a list of TGraph objects. For one given contour, more than
  one disjoint polyline may be generated. The number of TGraphs per
  countour is given by list->GetSize().
  Here we show only the case to access the first graph in the list.
    TGraph *gr1 = (TGraph*)list->First();


git-svn-id: http://root.cern.ch/svn/root/trunk@453 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@452 27541ba8-7e3a-0410-8455-c3a389f83636

in numbers-and-dots format.


git-svn-id: http://root.cern.ch/svn/root/trunk@451 27541ba8-7e3a-0410-8455-c3a389f83636

was not found (this caused the ROOT network classes to fail when trying
to connect to hosts having no hostname specified).


git-svn-id: http://root.cern.ch/svn/root/trunk@450 27541ba8-7e3a-0410-8455-c3a389f83636