The palette painting class.

A TPaletteAxis object is used to display the color palette when drawing 2-d histograms.

The TPaletteAxis is automatically created drawn when drawing a 2-D histogram when the option "Z" is specified.

A TPaletteAxis object is added to the histogram list of functions and can be retrieved doing:

TPaletteAxis *palette = (TPaletteAxis*)h->GetListOfFunctions()->FindObject("palette");

then the pointer palette can be used to change the pallette attributes.

Because the palette is created at painting time only, one must issue a:

gPad->Update();

before retrieving the palette pointer in order to create the palette. The following macro gives an example.

{
   TCanvas *c1 = new TCanvas("c1","c1",600,400);
   TH2F *h2 = new TH2F("h2","Example of a resized palette ",40,-4,4,40,-20,20);
   Float_t px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      h2->Fill(px,5*py);
   }
   gStyle->SetPalette(1);
   h2->Draw("COLZ");
   gPad->Update();
   TPaletteAxis *palette = (TPaletteAxis*)h2->GetListOfFunctions()->FindObject("palette");
   palette->SetY2NDC(0.7);
   return c1;
}

TPaletteAxis inherits from TBox and TPave. The methods allowing to specify the palette position are inherited from these two classes.

The palette can be interactively moved and resized. The context menu can be used to set the axis attributes.

It is possible to select a range on the axis to set the min/max in z

Definition at line 33 of file TPaletteAxis.h.

Public Types
enum	{ kHasView = BIT(11) }

Public Types inherited from TPave
enum	{ kNameIsAction = BIT(11) }

Public Types inherited from TBox
enum	{ kCannotMove = BIT(12) }
	True if box is being resized. More...

Public Types inherited from TObject
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) }

enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

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

Public Member Functions
	TPaletteAxis ()

	TPaletteAxis (Double_t x1, Double_t y1, Double_t x2, Double_t y2, TH1 *h)
	Palette normal constructor. More...

	TPaletteAxis (const TPaletteAxis &palette)
	Palette copy constructor. More...

virtual	~TPaletteAxis ()
	Palette destructor. More...

void	Copy (TObject &palette) const
	Copy a palette to a palette. More...

TPaletteAxis &	operator= (const TPaletteAxis &)
	Assignment operator. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Check if mouse on the axis region. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Check if mouse on the axis region. More...

TGaxis *	GetAxis ()

Int_t	GetBinColor (Int_t i, Int_t j)
	Returns the color index of the bin (i,j). More...

Option_t *	GetName () const
	Returns name of object. More...

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Displays the z value corresponding to cursor position py. More...

Int_t	GetValueColor (Double_t zc)
	Returns the color index of the given z value. More...

virtual void	Paint (Option_t *option="")
	Paint the palette. More...

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

virtual void	SetName (const char *name="")

virtual void	SetLabelColor (Int_t labelcolor)

virtual void	SetLabelFont (Int_t labelfont)

virtual void	SetLabelOffset (Float_t labeloffset)

virtual void	SetLabelSize (Float_t labelsize)

virtual void	SetTitleOffset (Float_t titleoffset=1)

virtual void	SetTitleSize (Float_t titlesize)

virtual void	SetLineColor (Color_t linecolor)

virtual void	SetLineWidth (Width_t linewidth)

virtual void	UnZoom ()
	Unzoom the palette. More...

Public Member Functions inherited from TPave
	TPave ()

	TPave (Double_t x1, Double_t y1, Double_t x2, Double_t y2, Int_t bordersize=4, Option_t *option="br")
	Pave normal constructor. More...

	TPave (const TPave &pave)
	Pave copy constructor. More...

virtual	~TPave ()
	Pave default destructor. More...

virtual void	ConvertNDCtoPad ()
	Convert pave coordinates from NDC to Pad coordinates. More...

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

virtual void	DrawPave (Double_t x1, Double_t y1, Double_t x2, Double_t y2, Int_t bordersize=4, Option_t *option="br")
	Draw this pave with new coordinates. More...

Int_t	GetBorderSize () const

Double_t	GetCornerRadius () const

Option_t *	GetOption () const

Int_t	GetShadowColor () const

Double_t	GetX1NDC () const

Double_t	GetX2NDC () const

Double_t	GetY1NDC () const

Double_t	GetY2NDC () const

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 this pave with its attributes. More...

virtual void	PaintPave (Double_t x1, Double_t y1, Double_t x2, Double_t y2, Int_t bordersize=4, Option_t *option="br")
	Draw this pave with new coordinates. More...

virtual void	PaintPaveArc (Double_t x1, Double_t y1, Double_t x2, Double_t y2, Int_t bordersize=4, Option_t *option="br")
	Draw this pave with rounded corners. More...

virtual void	Print (Option_t *option="") const
	Dump this pave with its attributes. More...

virtual void	SetBorderSize (Int_t bordersize=4)

virtual void	SetCornerRadius (Double_t rad=0.2)

virtual void	SetOption (Option_t *option="br")

virtual void	SetShadowColor (Int_t color)

virtual void	SetX1NDC (Double_t x1)

virtual void	SetX2NDC (Double_t x2)

virtual void	SetY1NDC (Double_t y1)

virtual void	SetY2NDC (Double_t y2)

virtual void	SetX1 (Double_t x1)
	Set the X1 value. More...

virtual void	SetX2 (Double_t x2)
	Set the X2 value. More...

virtual void	SetY1 (Double_t y1)
	Set the Y1 value. More...

virtual void	SetY2 (Double_t y2)
	Set the Y2 value. More...

Public Member Functions inherited from TBox
	TBox ()

	TBox (Double_t x1, Double_t y1, Double_t x2, Double_t y2)
	Box standard constructor. More...

	TBox (const TBox &box)
	Box copy constructor. More...

TBox &	operator= (const TBox &)
	Assignment operator. More...

virtual	~TBox ()
	Box destructor. More...

virtual TBox *	DrawBox (Double_t x1, Double_t y1, Double_t x2, Double_t y2)
	Draw this box with new coordinates. More...

Bool_t	IsBeingResized () const

Double_t	GetX1 () const

Double_t	GetX2 () const

Double_t	GetY1 () const

Double_t	GetY2 () const

virtual void	HideToolTip (Int_t event)
	Hide tool tip depending on the event type. More...

virtual Int_t	IsInside (Double_t x, Double_t y) const
	Function which returns 1 if point x,y lies inside the box, 0 otherwise. More...

virtual void	PaintBox (Double_t x1, Double_t y1, Double_t x2, Double_t y2, Option_t *option="")
	Draw this box with new coordinates. More...

virtual void	SetToolTipText (const char *text, Long_t delayms=1000)
	Set tool tip text associated with this box. More...

virtual Rectangle_t	GetBBox ()
	Return the "bounding Box" of the Box. More...

virtual TPoint	GetBBoxCenter ()
	Return the center of the Box as TPoint in pixels. More...

virtual void	SetBBoxCenter (const TPoint &p)
	Set center of the Box. More...

virtual void	SetBBoxCenterX (const Int_t x)
	Set X coordinate of the center of the Box. More...

virtual void	SetBBoxCenterY (const Int_t y)
	Set Y coordinate of the center of the Box. More...

virtual void	SetBBoxX1 (const Int_t x)
	Set left hand side of BoundingBox to a value (resize in x direction on left) More...

virtual void	SetBBoxX2 (const Int_t x)
	Set right hand side of BoundingBox to a value (resize in x direction on right) More...

virtual void	SetBBoxY1 (const Int_t y)
	Set top of BoundingBox to a value (resize in y direction on top) More...

virtual void	SetBBoxY2 (const Int_t y)
	Set bottom of BoundingBox to a value (resize in y direction on bottom) More...

Public Member Functions inherited from TObject
	TObject ()

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

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

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

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action. More...

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

virtual void	Clear (Option_t *="")

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

virtual Int_t	Compare (const TObject *obj) const
	Compare abstract method. 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 TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current pad. More...

virtual void	Dump () const
	Dump contents of object on stdout. 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 TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes. More...

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

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

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

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

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

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

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

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

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

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list. More...

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

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

void *	operator new (size_t sz)

void *	operator new[] (size_t sz)

void *	operator new (size_t sz, void *vp)

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

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

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

void	ResetBit (UInt_t f)

Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

void	InvertBit (UInt_t f)

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

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

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

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

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

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...

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

virtual Style_t	GetLineStyle () const

virtual Width_t	GetLineWidth () const

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

virtual void	SetLineStyle (Style_t lstyle)

	ClassDef (TAttLine, 2)

Public Member Functions inherited from TAttFill
	TAttFill ()

	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

virtual Style_t	GetFillStyle () const

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)

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

virtual void	SetFillStyle (Style_t fstyle)

Public Member Functions inherited from TAttBBox2D
virtual	~TAttBBox2D ()

	ClassDef (TAttBBox2D, 0)

Protected Attributes
TGaxis	fAxis

TH1 *	fH

TString	fName

Protected Attributes inherited from TPave
Double_t	fX1NDC

Double_t	fY1NDC

Double_t	fX2NDC

Double_t	fY2NDC

Int_t	fBorderSize

Int_t	fInit

Int_t	fShadowColor

Double_t	fCornerRadius

TString	fOption

TString	fName

Protected Attributes inherited from TBox
Double_t	fX1
	tool tip associated with box More...

Double_t	fY1

Double_t	fX2

Double_t	fY2

Bool_t	fResizing

Protected Attributes inherited from TAttLine
Color_t	fLineColor

Style_t	fLineStyle

Width_t	fLineWidth

Protected Attributes inherited from TAttFill
Color_t	fFillColor

Style_t	fFillStyle

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

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

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

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

Protected Member Functions inherited from TObject
void	MakeZombie ()

virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

#include <TPaletteAxis.h>

Inheritance diagram for TPaletteAxis:

[legend]

Member Enumeration Documentation

anonymous enum

Enumerator
kHasView

Definition at line 42 of file TPaletteAxis.h.

Constructor & Destructor Documentation

TPaletteAxis::TPaletteAxis ( )

TPaletteAxis::TPaletteAxis	(	Double_t	x1,
		Double_t	y1,
		Double_t	x2,
		Double_t	y2,
		TH1 *	h
	)

Palette normal constructor.

Definition at line 93 of file TPaletteAxis.cxx.

TPaletteAxis::TPaletteAxis ( const TPaletteAxis & palette )

Palette copy constructor.

Definition at line 115 of file TPaletteAxis.cxx.

TPaletteAxis::~TPaletteAxis ( )

virtual

Palette destructor.

Definition at line 107 of file TPaletteAxis.cxx.

Member Function Documentation

void TPaletteAxis::Copy ( TObject & palette ) const

virtual

Copy a palette to a palette.

Reimplemented from TPave.

Definition at line 134 of file TPaletteAxis.cxx.

Referenced by operator=().

Int_t TPaletteAxis::DistancetoPrimitive	(	Int_t	px,
		Int_t	py
	)

virtual

Check if mouse on the axis region.

Reimplemented from TPave.

Definition at line 145 of file TPaletteAxis.cxx.

void TPaletteAxis::ExecuteEvent	(	Int_t	event,
		Int_t	px,
		Int_t	py
	)

virtual

Check if mouse on the axis region.

Reimplemented from TPave.

Definition at line 160 of file TPaletteAxis.cxx.

TGaxis* TPaletteAxis::GetAxis ( )

inline

Definition at line 53 of file TPaletteAxis.h.

Int_t TPaletteAxis::GetBinColor	(	Int_t	i,
		Int_t	j
	)

Returns the color index of the bin (i,j).

This function should be used after an histogram has been plotted with the option COL or COLZ like in the following example:

h2->Draw("COLZ");
gPad->Update();
TPaletteAxis *palette = (TPaletteAxis*)h2->GetListOfFunctions()->FindObject("palette");
Int_t ci = palette->GetBinColor(20,15);

Then it is possible to retrieve the RGB components in the following way:

TColor *c = gROOT->GetColor(ci);
float x,y,z;
c->GetRGB(x,y,z);

Definition at line 271 of file TPaletteAxis.cxx.

Option_t* TPaletteAxis::GetName ( ) const

inlinevirtual

Returns name of object.

This default method returns the class name. Classes that give objects a name should override this method.

Reimplemented from TPave.

Definition at line 55 of file TPaletteAxis.h.

char * TPaletteAxis::GetObjectInfo	(	Int_t	px,
		Int_t	py
	)		const

virtual

Displays the z value corresponding to cursor position py.

Reimplemented from TObject.

Definition at line 281 of file TPaletteAxis.cxx.

Int_t TPaletteAxis::GetValueColor ( Double_t zc )

Returns the color index of the given z value.

This function should be used after an histogram has been plotted with the option COL or COLZ like in the following example:

h2->Draw("COLZ");
gPad->Update();
TPaletteAxis *palette = (TPaletteAxis*)h2->GetListOfFunctions()->FindObject("palette");
Int_t ci = palette->GetValueColor(30.);

Then it is possible to retrieve the RGB components in the following way:

TColor *c = gROOT->GetColor(ci);
float x,y,z;
c->GetRGB(x,y,z);

Definition at line 325 of file TPaletteAxis.cxx.

Referenced by GetBinColor().

TPaletteAxis & TPaletteAxis::operator= ( const TPaletteAxis & orig )

Assignment operator.

Definition at line 124 of file TPaletteAxis.cxx.

void TPaletteAxis::Paint ( Option_t * option = "" )

virtual

Paint the palette.

Reimplemented from TPave.

Definition at line 359 of file TPaletteAxis.cxx.

Referenced by THistPainter::PaintPalette().

void TPaletteAxis::SavePrimitive	(	std::ostream &	out,
		Option_t *	option = `""`
	)

virtual

Save primitive as a C++ statement(s) on output stream out.

Reimplemented from TPave.

Definition at line 448 of file TPaletteAxis.cxx.

virtual void TPaletteAxis::SetLabelColor ( Int_t labelcolor )

inlinevirtual

Definition at line 61 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetLabelFont ( Int_t labelfont )

inlinevirtual

Definition at line 62 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetLabelOffset ( Float_t labeloffset )

inlinevirtual

Definition at line 63 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetLabelSize ( Float_t labelsize )

inlinevirtual

Definition at line 64 of file TPaletteAxis.h.

Referenced by TMVA::correlations(), and TMVA::correlationsMultiClass().

virtual void TPaletteAxis::SetLineColor ( Color_t linecolor )

inlinevirtual

Reimplemented from TAttLine.

Definition at line 67 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetLineWidth ( Width_t linewidth )

inlinevirtual

Reimplemented from TAttLine.

Definition at line 68 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetName ( const char * name = "" )

inlinevirtual

Reimplemented from TPave.

Definition at line 60 of file TPaletteAxis.h.

Referenced by TPaletteAxis().

virtual void TPaletteAxis::SetTitleOffset ( Float_t titleoffset = 1 )

inlinevirtual

Definition at line 65 of file TPaletteAxis.h.

virtual void TPaletteAxis::SetTitleSize ( Float_t titlesize )

inlinevirtual

Definition at line 66 of file TPaletteAxis.h.

void TPaletteAxis::UnZoom ( )

virtual

Unzoom the palette.

Definition at line 478 of file TPaletteAxis.cxx.

Member Data Documentation

TGaxis TPaletteAxis::fAxis

protected

Definition at line 36 of file TPaletteAxis.h.

Referenced by GetAxis(), Paint(), SavePrimitive(), SetLabelColor(), SetLabelFont(), SetLabelOffset(), SetLabelSize(), SetLineColor(), SetLineWidth(), SetTitleOffset(), SetTitleSize(), and TPaletteAxis().

TH1* TPaletteAxis::fH

protected

Definition at line 37 of file TPaletteAxis.h.

Referenced by Copy(), ExecuteEvent(), GetBinColor(), GetObjectInfo(), GetValueColor(), Paint(), SavePrimitive(), TPaletteAxis(), and UnZoom().

TString TPaletteAxis::fName

protected

Definition at line 38 of file TPaletteAxis.h.

Referenced by Copy(), GetName(), and SetName().

Collaboration diagram for TPaletteAxis:

[legend]

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

hist/histpainter/inc/TPaletteAxis.h
hist/histpainter/src/TPaletteAxis.cxx

Public Types

Public Member Functions

Protected Attributes

Additional Inherited Members

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation