ROOT   6.10/09 Reference Guide
TGraphQQ Class Reference

This class allows to draw quantile-quantile plots.

Plots can be drawn for 2 datasets or for a dataset and a theoretical distribution function

## 2 datasets:

Quantile-quantile plots are used to determine whether 2 samples come from the same distribution. A qq-plot draws the quantiles of one dataset against the quantile of the the other. The quantiles of the dataset with fewer entries are on Y axis, with more entries - on X axis. A straight line, going through 0.25 and 0.75 quantiles is also plotted for reference. It represents a robust linear fit, not sensitive to the extremes of the datasets. If the datasets come from the same distribution, points of the plot should fall approximately on the 45 degrees line. If they have the same distribution function, but location or scale different parameters, they should still fall on the straight line, but not the 45 degrees one. The greater their departure from the straight line, the more evidence there is, that the datasets come from different distributions. The advantage of qq-plot is that it not only shows that the underlying distributions are different, but, unlike the analytical methods, it also gives information on the nature of this difference: heavier tails, different location/scale, different shape, etc.

Some examples of qqplots of 2 datasets:

## 1 dataset:

Quantile-quantile plots are used to determine if the dataset comes from the specified theoretical distribution, such as normal. A qq-plot draws quantiles of the dataset against quantiles of the specified theoretical distribution. (NOTE, that density, not CDF should be specified) A straight line, going through 0.25 and 0.75 quantiles can also be plotted for reference. It represents a robust linear fit, not sensitive to the extremes of the dataset. As in the 2 datasets case, departures from straight line indicate departures from the specified distribution.

"The correlation coefficient associated with the linear fit to the data in the probability plot (qq plot in our case) is a measure of the goodness of the fit. Estimates of the location and scale parameters of the distribution are given by the intercept and slope. Probability plots can be generated for several competing distributions to see which provides the best fit, and the probability plot generating the highest correlation coefficient is the best choice since it generates the straightest probability plot."

From "Engineering statistic handbook",

http://www.itl.nist.gov/div898/handbook/eda/section3/probplot.htm

Example of a qq-plot of a dataset from N(3, 2) distribution and TMath::Gaus(0, 1) theoretical function. Fitting parameters are estimates of the distribution mean and sigma.

References:

http://www.itl.nist.gov/div898/handbook/eda/section3/qqplot.htm

Definition at line 18 of file TGraphQQ.h.

## Public Member Functions

TGraphQQ ()
default constructor More...

TGraphQQ (Int_t n, Double_t *x)
Creates a quantile-quantile plot of dataset x. More...

TGraphQQ (Int_t n, Double_t *x, TF1 *f)
Creates a quantile-quantile plot of dataset x against function f. More...

TGraphQQ (Int_t nx, Double_t *x, Int_t ny, Double_t *y)
Creates a quantile-quantile plot of dataset x against dataset y Parameters nx and ny are respective array sizes. More...

virtual ~TGraphQQ ()
Destroys a TGraphQQ. More...

TF1GetF () const

Double_t GetXq1 () const

Double_t GetXq2 () const

Double_t GetYq1 () const

Double_t GetYq2 () const

void SetFunction (TF1 *f)
Sets the theoretical distribution function (density!) and computes its quantiles. More...

Public Member Functions inherited from TGraph
TGraph ()
Graph default constructor. More...

TGraph (Int_t n)
Constructor with only the number of points set the arrays x and y will be set later. More...

TGraph (Int_t n, const Int_t *x, const Int_t *y)
Graph normal constructor with ints. More...

TGraph (Int_t n, const Float_t *x, const Float_t *y)
Graph normal constructor with floats. More...

TGraph (Int_t n, const Double_t *x, const Double_t *y)
Graph normal constructor with doubles. More...

TGraph (const TGraph &gr)
Copy constructor for this graph. More...

TGraph (const TVectorF &vx, const TVectorF &vy)
Graph constructor with two vectors of floats in input A graph is build with the X coordinates taken from vx and Y coord from vy The number of points in the graph is the minimum of number of points in vx and vy. More...

TGraph (const TVectorD &vx, const TVectorD &vy)
Graph constructor with two vectors of doubles in input A graph is build with the X coordinates taken from vx and Y coord from vy The number of points in the graph is the minimum of number of points in vx and vy. More...

TGraph (const TH1 *h)
Graph constructor importing its parameters from the TH1 object passed as argument. More...

TGraph (const TF1 *f, Option_t *option="")
Graph constructor importing its parameters from the TF1 object passed as argument. More...

TGraph (const char *filename, const char *format="%lg %lg", Option_t *option="")
Graph constructor reading input from filename. More...

virtual ~TGraph ()
Graph default destructor. More...

virtual void Apply (TF1 *f)
Apply function f to all the data points f may be a 1-D function TF1 or 2-d function TF2 The Y values of the graph are replaced by the new values computed using the function. More...

virtual void Browse (TBrowser *b)
Browse. More...

virtual Double_t Chisquare (TF1 *f1, Option_t *option="") const
Return the chisquare of this graph with respect to f1. More...

virtual void ComputeRange (Double_t &xmin, Double_t &ymin, Double_t &xmax, Double_t &ymax) const
Compute the x/y range of the points in this graph. More...

virtual Int_t DistancetoPrimitive (Int_t px, Int_t py)
Compute distance from point px,py to a graph. More...

virtual void Draw (Option_t *chopt="")
Draw this graph with its current attributes. More...

virtual void DrawGraph (Int_t n, const Int_t *x, const Int_t *y, Option_t *option="")
Draw this graph with new attributes. More...

virtual void DrawGraph (Int_t n, const Float_t *x, const Float_t *y, Option_t *option="")
Draw this graph with new attributes. More...

virtual void DrawGraph (Int_t n, const Double_t *x=0, const Double_t *y=0, Option_t *option="")
Draw this graph with new attributes. More...

virtual void DrawPanel ()
Display a panel with all graph drawing options. More...

virtual Double_t Eval (Double_t x, TSpline *spline=0, Option_t *option="") const
Interpolate points in this graph at x using a TSpline. More...

virtual void ExecuteEvent (Int_t event, Int_t px, Int_t py)
Execute action corresponding to one event. More...

virtual void Expand (Int_t newsize)
If array sizes <= newsize, expand storage to 2*newsize. More...

virtual void Expand (Int_t newsize, Int_t step)
If graph capacity is less than newsize points then make array sizes equal to least multiple of step to contain newsize points. More...

virtual TObjectFindObject (const char *name) const
Search object named name in the list of functions. More...

virtual TObjectFindObject (const TObject *obj) const
Search object obj in the list of functions. More...

virtual TFitResultPtr Fit (const char *formula, Option_t *option="", Option_t *goption="", Axis_t xmin=0, Axis_t xmax=0)
Fit this graph with function with name fname. More...

virtual TFitResultPtr Fit (TF1 *f1, Option_t *option="", Option_t *goption="", Axis_t xmin=0, Axis_t xmax=0)
Fit this graph with function f1. More...

virtual void FitPanel ()
Display a GUI panel with all graph fit options. More...

virtual Double_t GetCorrelationFactor () const
Return graph correlation factor. More...

virtual Double_t GetCovariance () const
Return covariance of vectors x,y. More...

Bool_t GetEditable () const
Return kTRUE if kNotEditable bit is not set, kFALSE otherwise. More...

virtual Double_t GetErrorX (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_t GetErrorXhigh (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_t GetErrorXlow (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_t GetErrorY (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_t GetErrorYhigh (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_t GetErrorYlow (Int_t bin) const
This function is called by GraphFitChisquare. More...

virtual Double_tGetEX () const

virtual Double_tGetEXhigh () const

virtual Double_tGetEXhighd () const

virtual Double_tGetEXlow () const

virtual Double_tGetEXlowd () const

virtual Double_tGetEY () const

virtual Double_tGetEYhigh () const

virtual Double_tGetEYhighd () const

virtual Double_tGetEYlow () const

virtual Double_tGetEYlowd () const

TF1GetFunction (const char *name) const
Return pointer to function with name. More...

TH1FGetHistogram () const
Returns a pointer to the histogram used to draw the axis Takes into account the two following cases. More...

TListGetListOfFunctions () const

Double_t GetMaximum () const

Int_t GetMaxSize () const

virtual Double_t GetMean (Int_t axis=1) const
Return mean value of X (axis=1) or Y (axis=2) More...

Double_t GetMinimum () const

Int_t GetN () const

virtual Int_t GetPoint (Int_t i, Double_t &x, Double_t &y) const
Get x and y values for point number i. More...

virtual Double_t GetRMS (Int_t axis=1) const
Return RMS of X (axis=1) or Y (axis=2) More...

Double_tGetX () const

TAxisGetXaxis () const
Get x axis of the graph. More...

Double_tGetY () const

TAxisGetYaxis () const
Get y axis of the graph. More...

virtual void InitExpo (Double_t xmin=0, Double_t xmax=0)
Compute Initial values of parameters for an exponential. More...

virtual void InitGaus (Double_t xmin=0, Double_t xmax=0)
Compute Initial values of parameters for a gaussian. More...

virtual void InitPolynom (Double_t xmin=0, Double_t xmax=0)
Compute Initial values of parameters for a polynom. More...

virtual Int_t InsertPoint ()
Insert a new point at the mouse position. More...

virtual Double_t Integral (Int_t first=0, Int_t last=-1) const
Integrate the TGraph data within a given (index) range. More...

virtual Bool_t IsEditable () const

virtual Int_t IsInside (Double_t x, Double_t y) const
Return 1 if the point (x,y) is inside the polygon defined by the graph vertices 0 otherwise. More...

virtual void LeastSquareFit (Int_t m, Double_t *a, Double_t xmin=0, Double_t xmax=0)
Least squares polynomial fitting without weights. More...

virtual void LeastSquareLinearFit (Int_t n, Double_t &a0, Double_t &a1, Int_t &ifail, Double_t xmin=0, Double_t xmax=0)
Least square linear fit without weights. More...

virtual Int_t Merge (TCollection *list)
Adds all graphs from the collection to this graph. More...

TGraphoperator= (const TGraph &)
Equal operator for this graph. More...

virtual void Paint (Option_t *chopt="")
Draw this graph with its current attributes. More...

void PaintGraph (Int_t npoints, const Double_t *x, const Double_t *y, Option_t *chopt)
Draw the (x,y) as a graph. More...

void PaintGrapHist (Int_t npoints, const Double_t *x, const Double_t *y, Option_t *chopt)
Draw the (x,y) as a histogram. More...

virtual void PaintStats (TF1 *fit)
Draw the stats. More...

virtual void Print (Option_t *chopt="") const
Print graph values. More...

virtual void RecursiveRemove (TObject *obj)
Recursively remove object from the list of functions. More...

virtual Int_t RemovePoint ()
Delete point close to the mouse position. More...

virtual Int_t RemovePoint (Int_t ipoint)
Delete point number ipoint. More...

virtual void SavePrimitive (std::ostream &out, Option_t *option="")
Save primitive as a C++ statement(s) on output stream out. More...

virtual void Set (Int_t n)
Set number of points in the graph Existing coordinates are preserved New coordinates above fNpoints are preset to 0. More...

virtual void SetEditable (Bool_t editable=kTRUE)
if editable=kFALSE, the graph cannot be modified with the mouse by default a TGraph is editable More...

virtual void SetHistogram (TH1F *h)

virtual void SetMaximum (Double_t maximum=-1111)
Set the maximum of the graph. More...

virtual void SetMinimum (Double_t minimum=-1111)
Set the minimum of the graph. More...

virtual void SetPoint (Int_t i, Double_t x, Double_t y)
Set x and y values for point number i. More...

virtual void SetTitle (const char *title="")
Set graph title. More...

virtual void Sort (Bool_t(*greater)(const TGraph *, Int_t, Int_t)=&TGraph::CompareX, Bool_t ascending=kTRUE, Int_t low=0, Int_t high=-1111)
Sorts the points of this TGraph using in-place quicksort (see e.g. More...

virtual void UseCurrentStyle ()
Set current style settings in this graph This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

void Zero (Int_t &k, Double_t AZ, Double_t BZ, Double_t E2, Double_t &X, Double_t &Y, Int_t maxiterations)
Find zero of a continuous function. More...

Public Member Functions inherited from TNamed
TNamed ()

TNamed (const char *name, const char *title)

TNamed (const TString &name, const TString &title)

TNamed (const TNamed &named)
TNamed copy ctor. More...

virtual ~TNamed ()

virtual void Clear (Option_t *option="")
Set name and title to empty strings (""). More...

virtual TObjectClone (const char *newname="") const
Make a clone of an object using the Streamer facility. More...

virtual Int_t Compare (const TObject *obj) const
Compare two TNamed objects. More...

virtual void Copy (TObject &named) const
Copy this to obj. More...

virtual void FillBuffer (char *&buffer)
Encode TNamed into output buffer. More...

virtual const char * GetName () const
Returns name of object. More...

virtual const char * GetTitle () const
Returns title of object. More...

virtual ULong_t Hash () const
Return hash value for this object. More...

virtual Bool_t IsSortable () const

virtual void ls (Option_t *option="") const
List TNamed name and title. More...

TNamedoperator= (const TNamed &rhs)
TNamed assignment operator. More...

virtual void SetName (const char *name)
Set the name of the TNamed. More...

virtual void SetNameTitle (const char *name, const char *title)
Set all the TNamed parameters (name and title). More...

virtual Int_t Sizeof () const
Return size of the TNamed part of the TObject. More...

Public Member Functions inherited from TObject
TObject ()
TObject constructor. More...

TObject (const TObject &object)
TObject copy ctor. More...

virtual ~TObject ()
TObject destructor. More...

void AbstractMethod (const char *method) const
Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

Append graphics object to current pad. More...

virtual const char * ClassName () const
Returns name of class to which the object belongs. More...

virtual void Delete (Option_t *option="")
Delete this object. More...

virtual void DrawClass () const
Draw class inheritance tree of the class to which this object belongs. More...

virtual TObjectDrawClone (Option_t *option="") const
Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad). More...

virtual void Dump () const
Dump contents of object on stdout. More...

virtual void Error (const char *method, const char *msgfmt,...) const
Issue error message. More...

virtual void Execute (const char *method, const char *params, Int_t *error=0)
Execute method on this object with the given parameter string, e.g. More...

virtual void Execute (TMethod *method, TObjArray *params, Int_t *error=0)
Execute method on this object with parameters stored in the TObjArray. More...

virtual void Fatal (const char *method, const char *msgfmt,...) const
Issue fatal error message. More...

virtual Option_tGetDrawOption () const
Get option used by the graphics system to draw this object. More...

virtual const char * GetIconName () const
Returns mime type name of object. More...

virtual char * GetObjectInfo (Int_t px, Int_t py) const
Returns string containing info about the object at position (px,py). More...

virtual Option_tGetOption () const

virtual UInt_t GetUniqueID () const
Return the unique object id. More...

virtual Bool_t HandleTimer (TTimer *timer)
Execute action in response of a timer timing out. More...

virtual void Info (const char *method, const char *msgfmt,...) const
Issue info message. More...

virtual Bool_t InheritsFrom (const char *classname) const
Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t InheritsFrom (const TClass *cl) const
Returns kTRUE if object inherits from TClass cl. More...

virtual void Inspect () const
Dump contents of this object in a graphics canvas. More...

void InvertBit (UInt_t f)

virtual Bool_t IsEqual (const TObject *obj) const
Default equal comparison (objects are equal if they have the same address in memory). More...

virtual Bool_t IsFolder () const
Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

Bool_t IsOnHeap () const

Bool_t IsZombie () const

void MayNotUse (const char *method) const
Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). More...

virtual Bool_t Notify ()
This method must be overridden to handle object notification. More...

void Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const
Use this method to declare a method obsolete. More...

void operator delete (void *ptr)
Operator delete. More...

void operator delete[] (void *ptr)
Operator delete []. More...

voidoperator new (size_t sz)

voidoperator new (size_t sz, void *vp)

voidoperator new[] (size_t sz)

voidoperator new[] (size_t sz, void *vp)

TObjectoperator= (const TObject &rhs)
TObject assignment operator. More...

virtual void Pop ()
Pop on object drawn in a pad to the top of the display list. More...

virtual Int_t Read (const char *name)
Read contents of object with specified name from the current directory. More...

void ResetBit (UInt_t f)

virtual void SaveAs (const char *filename="", Option_t *option="") const
Save this object in the file specified by filename. More...

void SetBit (UInt_t f, Bool_t set)
Set or unset the user status bits as specified in f. More...

void SetBit (UInt_t f)

virtual void SetDrawOption (Option_t *option="")
Set drawing option for object. More...

virtual void SetUniqueID (UInt_t uid)
Set the unique object id. More...

virtual void SysError (const char *method, const char *msgfmt,...) const
Issue system error message. More...

Bool_t TestBit (UInt_t f) const

Int_t TestBits (UInt_t f) const

virtual void Warning (const char *method, const char *msgfmt,...) const
Issue warning message. More...

virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
Write this object to the current directory. More...

virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
Write this object to the current directory. More...

Public Member Functions inherited from TAttLine
TAttLine ()
AttLine default constructor. More...

TAttLine (Color_t lcolor, Style_t lstyle, Width_t lwidth)
AttLine normal constructor. More...

virtual ~TAttLine ()
AttLine destructor. More...

void Copy (TAttLine &attline) const
Copy this line attributes to a new TAttLine. More...

Int_t DistancetoLine (Int_t px, Int_t py, Double_t xp1, Double_t yp1, Double_t xp2, Double_t yp2)
Compute distance from point px,py to a line. More...

virtual Color_t GetLineColor () const
Return the line color. More...

virtual Style_t GetLineStyle () const
Return the line style. More...

virtual Width_t GetLineWidth () const
Return the line width. More...

virtual void Modify ()
Change current line attributes if necessary. More...

virtual void ResetAttLine (Option_t *option="")
Reset this line attributes to default values. More...

virtual void SaveLineAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t widdef=1)
Save line attributes as C++ statement(s) on output stream out. More...

virtual void SetLineAttributes ()
Invoke the DialogCanvas Line attributes. More...

virtual void SetLineColor (Color_t lcolor)
Set the line color. More...

virtual void SetLineColorAlpha (Color_t lcolor, Float_t lalpha)
Set a transparent line color. More...

virtual void SetLineStyle (Style_t lstyle)
Set the line style. More...

virtual void SetLineWidth (Width_t lwidth)
Set the line width. More...

Public Member Functions inherited from TAttFill
TAttFill ()
AttFill default constructor. More...

TAttFill (Color_t fcolor, Style_t fstyle)
AttFill normal constructor. More...

virtual ~TAttFill ()
AttFill destructor. More...

void Copy (TAttFill &attfill) const
Copy this fill attributes to a new TAttFill. More...

virtual Color_t GetFillColor () const
Return the fill area color. More...

virtual Style_t GetFillStyle () const
Return the fill area style. More...

virtual Bool_t IsTransparent () const

virtual void Modify ()
Change current fill area attributes if necessary. More...

virtual void ResetAttFill (Option_t *option="")
Reset this fill attributes to default values. More...

virtual void SaveFillAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1001)
Save fill attributes as C++ statement(s) on output stream out. More...

virtual void SetFillAttributes ()
Invoke the DialogCanvas Fill attributes. More...

virtual void SetFillColor (Color_t fcolor)
Set the fill area color. More...

virtual void SetFillColorAlpha (Color_t fcolor, Float_t falpha)
Set a transparent fill color. More...

virtual void SetFillStyle (Style_t fstyle)
Set the fill area style. More...

Public Member Functions inherited from TAttMarker
TAttMarker ()
TAttMarker default constructor. More...

TAttMarker (Color_t color, Style_t style, Size_t msize)
TAttMarker normal constructor. More...

virtual ~TAttMarker ()
TAttMarker destructor. More...

void Copy (TAttMarker &attmarker) const
Copy this marker attributes to a new TAttMarker. More...

virtual Color_t GetMarkerColor () const
Return the marker color. More...

virtual Size_t GetMarkerSize () const
Return the marker size. More...

virtual Style_t GetMarkerStyle () const
Return the marker style. More...

virtual void Modify ()
Change current marker attributes if necessary. More...

virtual void ResetAttMarker (Option_t *toption="")
Reset this marker attributes to the default values. More...

virtual void SaveMarkerAttributes (std::ostream &out, const char *name, Int_t coldef=1, Int_t stydef=1, Int_t sizdef=1)
Save line attributes as C++ statement(s) on output stream out. More...

virtual void SetMarkerAttributes ()
Invoke the DialogCanvas Marker attributes. More...

virtual void SetMarkerColor (Color_t mcolor=1)
Set the marker color. More...

virtual void SetMarkerColorAlpha (Color_t mcolor, Float_t malpha)
Set a transparent marker color. More...

virtual void SetMarkerSize (Size_t msize=1)
Set the marker size. More...

virtual void SetMarkerStyle (Style_t mstyle=1)
Set the marker style. More...

## Protected Member Functions

void MakeFunctionQuantiles ()
Computes quantiles of theoretical distribution function. More...

void MakeQuantiles ()
When sample sizes are not equal, computes quantiles of the bigger sample by linear interpolation. More...

void Quartiles ()
compute quartiles a quartile is a 25 per cent or 75 per cent quantile More...

Protected Member Functions inherited from TGraph
virtual Double_t ** Allocate (Int_t newsize)

Double_t ** AllocateArrays (Int_t Narrays, Int_t arraySize)
Allocate arrays. More...

virtual void CopyAndRelease (Double_t **newarrays, Int_t ibegin, Int_t iend, Int_t obegin)
Copy points from fX and fY to arrays[0] and arrays[1] or to fX and fY if arrays == 0 and ibegin != iend. More...

virtual Bool_t CopyPoints (Double_t **newarrays, Int_t ibegin, Int_t iend, Int_t obegin)
Copy points from fX and fY to arrays[0] and arrays[1] or to fX and fY if arrays == 0 and ibegin != iend. More...

Bool_t CtorAllocate ()
In constructors set fNpoints than call this method. More...

virtual Bool_t DoMerge (const TGraph *g)
protected function to perform the merge operation of a graph More...

Double_t ** ExpandAndCopy (Int_t size, Int_t iend)
if size > fMaxSize allocate new arrays of 2*size points and copy iend first points. More...

virtual void FillZero (Int_t begin, Int_t end, Bool_t from_ctor=kTRUE)
Set zero values for point arrays in the range [begin, end) Should be redefined in descendant classes. More...

Double_t ** ShrinkAndCopy (Int_t size, Int_t iend)
if size*2 <= fMaxSize allocate new arrays of size points, copy points [0,oend). More...

virtual void SwapPoints (Int_t pos1, Int_t pos2)
Swap points. More...

Protected Member Functions inherited from TObject
virtual void DoError (int level, const char *location, const char *fmt, va_list va) const
Interface to ErrorHandler (protected). More...

void MakeZombie ()

## Protected Attributes

TF1fF
theoretical density function, if specified More...

Int_t fNy0
size of the fY0 dataset More...

Double_t fXq1
x1 coordinate of the interquartile line More...

Double_t fXq2
x2 coordinate of the interquartile line More...

Double_tfY0
! second dataset, if specified More...

Double_t fYq1
y1 coordinate of the interquartile line More...

Double_t fYq2
y2 coordinate of the interquartile line More...

Protected Attributes inherited from TGraph
TListfFunctions
Pointer to list of functions (fits and user) More...

TH1FfHistogram
Pointer to histogram used for drawing axis. More...

Double_t fMaximum
Maximum value for plotting along y. More...

Int_t fMaxSize
!Current dimension of arrays fX and fY More...

Double_t fMinimum
Minimum value for plotting along y. More...

Int_t fNpoints
Number of points <= fMaxSize. More...

Double_tfX
[fNpoints] array of X points More...

Double_tfY
[fNpoints] array of Y points More...

Protected Attributes inherited from TNamed
TString fName

TString fTitle

Protected Attributes inherited from TAttLine
Color_t fLineColor
Line color. More...

Style_t fLineStyle
Line style. More...

Width_t fLineWidth
Line width. More...

Protected Attributes inherited from TAttFill
Color_t fFillColor
Fill area color. More...

Style_t fFillStyle
Fill area style. More...

Protected Attributes inherited from TAttMarker
Color_t fMarkerColor
Marker color. More...

Size_t fMarkerSize
Marker size. More...

Style_t fMarkerStyle
Marker style. More...

Public Types inherited from TGraph
enum  { kClipFrame = BIT(10), kResetHisto = BIT(17), kNotEditable = BIT(18), kIsSortedX = BIT(19) }

Public Types inherited from TObject
enum  { kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

enum  { kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) }

enum  EStatusBits {
kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4),
kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13)
}

Static Public Member Functions inherited from TGraph
static Bool_t CompareArg (const TGraph *gr, Int_t left, Int_t right)
Return kTRUE if point number "left"'s argument (angle with respect to positive x-axis) is bigger than that of point number "right". More...

static Bool_t CompareRadius (const TGraph *gr, Int_t left, Int_t right)
Return kTRUE if point number "left"'s distance to origin is bigger than that of point number "right". More...

static Bool_t CompareX (const TGraph *gr, Int_t left, Int_t right)
Return kTRUE if fX[left] > fX[right]. Can be used by Sort. More...

static Bool_t CompareY (const TGraph *gr, Int_t left, Int_t right)
Return kTRUE if fY[left] > fY[right]. Can be used by Sort. More...

Static Public Member Functions inherited from TObject
static Long_t GetDtorOnly ()
Return destructor only flag. More...

static Bool_t GetObjectStat ()
Get status of object stat flag. More...

static void SetDtorOnly (void *obj)
Set destructor only flag. More...

static void SetObjectStat (Bool_t stat)
Turn on/off tracking of objects in the TObjectTable. More...

Static Protected Member Functions inherited from TGraph
static void SwapValues (Double_t *arr, Int_t pos1, Int_t pos2)
Swap values. More...

#include <TGraphQQ.h>

Inheritance diagram for TGraphQQ:
[legend]

## ◆ TGraphQQ() [1/4]

 TGraphQQ::TGraphQQ ( )

default constructor

Definition at line 94 of file TGraphQQ.cxx.

## ◆ TGraphQQ() [2/4]

 TGraphQQ::TGraphQQ ( Int_t n, Double_t * x )

Creates a quantile-quantile plot of dataset x.

Theoretical distribution function can be defined later by SetFunction method

Definition at line 110 of file TGraphQQ.cxx.

## ◆ TGraphQQ() [3/4]

 TGraphQQ::TGraphQQ ( Int_t n, Double_t * x, TF1 * f )

Creates a quantile-quantile plot of dataset x against function f.

Definition at line 131 of file TGraphQQ.cxx.

## ◆ TGraphQQ() [4/4]

 TGraphQQ::TGraphQQ ( Int_t nx, Double_t * x, Int_t ny, Double_t * y )

Creates a quantile-quantile plot of dataset x against dataset y Parameters nx and ny are respective array sizes.

Definition at line 150 of file TGraphQQ.cxx.

## ◆ ~TGraphQQ()

 TGraphQQ::~TGraphQQ ( )
virtual

Destroys a TGraphQQ.

Definition at line 200 of file TGraphQQ.cxx.

## ◆ GetF()

 TF1* TGraphQQ::GetF ( ) const
inline

Definition at line 44 of file TGraphQQ.h.

## ◆ GetXq1()

 Double_t TGraphQQ::GetXq1 ( ) const
inline

Definition at line 40 of file TGraphQQ.h.

## ◆ GetXq2()

 Double_t TGraphQQ::GetXq2 ( ) const
inline

Definition at line 41 of file TGraphQQ.h.

## ◆ GetYq1()

 Double_t TGraphQQ::GetYq1 ( ) const
inline

Definition at line 42 of file TGraphQQ.h.

## ◆ GetYq2()

 Double_t TGraphQQ::GetYq2 ( ) const
inline

Definition at line 43 of file TGraphQQ.h.

## ◆ MakeFunctionQuantiles()

 void TGraphQQ::MakeFunctionQuantiles ( )
protected

Computes quantiles of theoretical distribution function.

Definition at line 211 of file TGraphQQ.cxx.

## ◆ MakeQuantiles()

 void TGraphQQ::MakeQuantiles ( )
protected

When sample sizes are not equal, computes quantiles of the bigger sample by linear interpolation.

Definition at line 243 of file TGraphQQ.cxx.

## ◆ Quartiles()

 void TGraphQQ::Quartiles ( )
protected

compute quartiles a quartile is a 25 per cent or 75 per cent quantile

Definition at line 266 of file TGraphQQ.cxx.

## ◆ SetFunction()

 void TGraphQQ::SetFunction ( TF1 * f )

Sets the theoretical distribution function (density!) and computes its quantiles.

Definition at line 292 of file TGraphQQ.cxx.

## ◆ fF

 TF1* TGraphQQ::fF
protected

theoretical density function, if specified

Definition at line 26 of file TGraphQQ.h.

## ◆ fNy0

 Int_t TGraphQQ::fNy0
protected

size of the fY0 dataset

Definition at line 20 of file TGraphQQ.h.

## ◆ fXq1

 Double_t TGraphQQ::fXq1
protected

x1 coordinate of the interquartile line

Definition at line 21 of file TGraphQQ.h.

## ◆ fXq2

 Double_t TGraphQQ::fXq2
protected

x2 coordinate of the interquartile line

Definition at line 22 of file TGraphQQ.h.

## ◆ fY0

 Double_t* TGraphQQ::fY0
protected

! second dataset, if specified

Definition at line 25 of file TGraphQQ.h.

## ◆ fYq1

 Double_t TGraphQQ::fYq1
protected

y1 coordinate of the interquartile line

Definition at line 23 of file TGraphQQ.h.

## ◆ fYq2

 Double_t TGraphQQ::fYq2
protected

y2 coordinate of the interquartile line

Definition at line 24 of file TGraphQQ.h.

The documentation for this class was generated from the following files: