ROOT » GRAF2D » GRAF » TLatex

class TLatex: public TText, public TAttLine

TLatex : to draw Mathematical Formula

TLatex's purpose is to write mathematical equations. The syntax is very similar to Latex's. It provides several functionalities: When the font precision (see TAttText) is low (0 or 1), TLatex is painted as a normal TText, the control characters are not interpreted.

Subscripts and Superscripts

Subscripts and superscripts are made with the _ and ^ commands. These commands can be combined to make complicated subscript and superscript expressions. You may adjust the display of subscripts and superscripts by using the two functions SetIndiceSize(Double_t), which set relative size of subscripts and superscripts, and SetLimitIndiceSize(Int_t), which set limits for text resizing of subscipts and superscripts.

Examples: 

   x^{2y} :    x^{2y} x_{2y} :    x_{2y}
   x^{y^{2}} : x^{y^{2}} x^{y_{1}} : x^{y_{1}}
   x^{y}_{1} : x^{y}_{1} x_{1}^{y} : x_{1}^{y}
The best way to put the subscipts and superscripts before the character and not after, is to use an empty character: 
   {}^{40}_{20}Ca : {}^{40}_{20}Ca
The subscripts and superscripts operators apply not only on one character but on all the "normal text" preceding them. In the following example the second E is lower than the first one because the operator _ is applied on /f which has a descending part, and not only on f which as no descending part. 
   f_{E}/f_{E} : f_{E}/f_{E}
To make sure the second operator _ applies only on f a dummy operator ^{} should be introduced to separate the f from the /. 
   f_{E}/^{}f_{E} : f_{E}/^{}f_{E}

Fractions

Fractions denoted by the / symbol are made in the obvious way. The #frac command is used for large fractions in displayed formula; it has two arguments: the numerator and the denominator.

Examples: 

   x = #frac{y+z/2}{y^{2}+1} : x = #frac{y+z/2}{y^{2}+1}

Splitting Lines

Text can be split in two lines via the command #splitline.

Examples: 

   #splitline{21 April 2003}{14:02:30} : #splitline{21 April 2003}{14:02:30}

Roots

The #sqrt command produces the square root of its argument; it has an optional first argument for other roots.

Examples: 

   #sqrt{10} : #sqrt{10} #sqrt[3]{10} : #sqrt[3]{10}

Mathematical Symbols

TLatex can display dozens of special mathematical symbols. A few of them, such as + and > , are produced by typing the corresponding keyboard character. Others are obtained with the commands in the following table: 

Picture
Source



output of html600/MACRO_TLatex_21.gif


TCanvas *mathsymbols()
{
   TCanvas *Ms = new TCanvas("mathsymb","Mathematical Symbols",800,500);

   TLatex Tl;
   Tl.SetTextSize(0.033);

   // Draw First Column
   Tl.SetTextAlign(12);
   float y, x1, x2;
   float step = 0.054;
   y = 0.96; x1 = 0.02; x2 = x1+0.04;
               Tl.DrawLatex(x1, y, "#club")           ; Tl.DrawText(x2, y, "#club");
   y -= step ; Tl.DrawLatex(x1, y, "#voidn")          ; Tl.DrawText(x2, y, "#voidn");
   y -= step ; Tl.DrawLatex(x1, y, "#leq")            ; Tl.DrawText(x2, y, "#leq");
   y -= step ; Tl.DrawLatex(x1, y, "#approx")         ; Tl.DrawText(x2, y, "#approx");
   y -= step ; Tl.DrawLatex(x1, y, "#in")             ; Tl.DrawText(x2, y, "#in");
   y -= step ; Tl.DrawLatex(x1, y, "#supset")         ; Tl.DrawText(x2, y, "#supset");
   y -= step ; Tl.DrawLatex(x1, y, "#cap")            ; Tl.DrawText(x2, y, "#cap");
   y -= step ; Tl.DrawLatex(x1, y, "#ocopyright")     ; Tl.DrawText(x2, y, "#ocopyright");
   y -= step ; Tl.DrawLatex(x1, y, "#trademark")      ; Tl.DrawText(x2, y, "#trademark");
   y -= step ; Tl.DrawLatex(x1, y, "#times")          ; Tl.DrawText(x2, y, "#times");
   y -= step ; Tl.DrawLatex(x1, y, "#bullet")         ; Tl.DrawText(x2, y, "#bullet");
   y -= step ; Tl.DrawLatex(x1, y, "#voidb")          ; Tl.DrawText(x2, y, "#voidb");
   y -= step ; Tl.DrawLatex(x1, y, "#doublequote")    ; Tl.DrawText(x2, y, "#doublequote");
   y -= step ; Tl.DrawLatex(x1, y, "#lbar")           ; Tl.DrawText(x2, y, "#lbar");
   y -= step ; Tl.DrawLatex(x1, y, "#arcbottom")      ; Tl.DrawText(x2, y, "#arcbottom");
   y -= step ; Tl.DrawLatex(x1, y, "#downarrow")      ; Tl.DrawText(x2, y, "#downarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#leftrightarrow") ; Tl.DrawText(x2, y, "#leftrightarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#Downarrow")      ; Tl.DrawText(x2, y, "#Downarrow");

   // Draw Second Column
   y = 0.96; x1 = 0.22; x2 = x1+0.04;
               Tl.DrawLatex(x1, y, "#Leftrightarrow") ; Tl.DrawText(x2, y, "#Leftrightarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#void8")          ; Tl.DrawText(x2, y, "#void8");
   y -= step ; Tl.DrawLatex(x1, y, "#hbar")           ; Tl.DrawText(x2, y, "#hbar");
   y -= step ; Tl.DrawLatex(x1, y, "#diamond")        ; Tl.DrawText(x2, y, "#diamond");
   y -= step ; Tl.DrawLatex(x1, y, "#aleph")          ; Tl.DrawText(x2, y, "#aleph");
   y -= step ; Tl.DrawLatex(x1, y, "#geq")            ; Tl.DrawText(x2, y, "#geq");
   y -= step ; Tl.DrawLatex(x1, y, "#neq")            ; Tl.DrawText(x2, y, "#neq");
   y -= step ; Tl.DrawLatex(x1, y, "#notin")          ; Tl.DrawText(x2, y, "#notin");
   y -= step ; Tl.DrawLatex(x1, y, "#subseteq")       ; Tl.DrawText(x2, y, "#subseteq");
   y -= step ; Tl.DrawLatex(x1, y, "#cup")            ; Tl.DrawText(x2, y, "#cup");
   y -= step ; Tl.DrawLatex(x1, y, "#copyright")      ; Tl.DrawText(x2, y, "#copyright");
   y -= step ; Tl.DrawLatex(x1, y, "#void3")          ; Tl.DrawText(x2, y, "#void3");
   y -= step ; Tl.DrawLatex(x1, y, "#divide")         ; Tl.DrawText(x2, y, "#divide");
   y -= step ; Tl.DrawLatex(x1, y, "#circ")           ; Tl.DrawText(x2, y, "#circ");
   y -= step ; Tl.DrawLatex(x1, y, "#infty")          ; Tl.DrawText(x2, y, "#infty");
   y -= step ; Tl.DrawLatex(x1, y, "#angle")          ; Tl.DrawText(x2, y, "#angle");
   y -= step ; Tl.DrawLatex(x1, y, "#cbar")           ; Tl.DrawText(x2, y, "#cbar");
   y -= step ; Tl.DrawLatex(x1, y, "#arctop")         ; Tl.DrawText(x2, y, "#arctop");

   // Draw Third Column
   y = 0.96; x1 = 0.42; x2 = x1+0.04;
               Tl.DrawLatex(x1, y, "#leftarrow")      ; Tl.DrawText(x2, y, "#leftarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#otimes")         ; Tl.DrawText(x2, y, "#otimes");
   y -= step ; Tl.DrawLatex(x1, y, "#Leftarrow")      ; Tl.DrawText(x2, y, "#Leftarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#prod")           ; Tl.DrawText(x2, y, "#prod");
   y -= step ; Tl.DrawLatex(x1, y, "#Box")            ; Tl.DrawText(x2, y, "#Box");
   y -= step ; Tl.DrawLatex(x1, y, "#parallel")       ; Tl.DrawText(x2, y, "#parallel");
   y -= step ; Tl.DrawLatex(x1, y, "#heart")          ; Tl.DrawText(x2, y, "#heart");
   y -= step ; Tl.DrawLatex(x1, y, "#Jgothic")        ; Tl.DrawText(x2, y, "#Jgothic");
   y -= step ; Tl.DrawLatex(x1, y, "#LT")             ; Tl.DrawText(x2, y, "#LT");
   y -= step ; Tl.DrawLatex(x1, y, "#equiv")          ; Tl.DrawText(x2, y, "#equiv");
   y -= step ; Tl.DrawLatex(x1, y, "#subset")         ; Tl.DrawText(x2, y, "#subset");
   y -= step ; Tl.DrawLatex(x1, y, "#supseteq")       ; Tl.DrawText(x2, y, "#supseteq");
   y -= step ; Tl.DrawLatex(x1, y, "#wedge")          ; Tl.DrawText(x2, y, "#wedge");
   y -= step ; Tl.DrawLatex(x1, y, "#oright")         ; Tl.DrawText(x2, y, "#oright");
   y -= step ; Tl.DrawLatex(x1, y, "#AA")             ; Tl.DrawText(x2, y, "#AA");
   y -= step ; Tl.DrawLatex(x1, y, "#pm")             ; Tl.DrawText(x2, y, "#pm");
   y -= step ; Tl.DrawLatex(x1, y, "#mp")             ; Tl.DrawText(x2, y, "#mp");
   y -= step ; Tl.DrawLatex(x1, y, "#3dots")          ; Tl.DrawText(x2, y, "#3dots");

   // Draw Fourth Column
   y = 0.96; x1 = 0.62; x2 = x1+0.04;
               Tl.DrawLatex(x1, y, "#nabla")          ; Tl.DrawText(x2, y, "#nabla");
   y -= step ; Tl.DrawLatex(x1, y, "#downleftarrow")  ; Tl.DrawText(x2, y, "#downleftarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#topbar")         ; Tl.DrawText(x2, y, "#topbar");
   y -= step ; Tl.DrawLatex(x1, y, "#arcbar")         ; Tl.DrawText(x2, y, "#arcbar");
   y -= step ; Tl.DrawLatex(x1, y, "#uparrow")        ; Tl.DrawText(x2, y, "#uparrow");
   y -= step ; Tl.DrawLatex(x1, y, "#oplus")          ; Tl.DrawText(x2, y, "#oplus");
   y -= step ; Tl.DrawLatex(x1, y, "#Uparrow")        ; Tl.DrawText(x2, y, "#Uparrow");
   y -= step ; Tl.DrawLatex(x1, y-0.01, "#sum")       ; Tl.DrawText(x2, y, "#sum");
   y -= step ; Tl.DrawLatex(x1, y, "#perp")           ; Tl.DrawText(x2, y, "#perp");
   y -= step ; Tl.DrawLatex(x1, y, "#forall")         ; Tl.DrawText(x2, y, "#forall");
   y -= step ; Tl.DrawLatex(x1, y, "#spade")          ; Tl.DrawText(x2, y, "#spade");
   y -= step ; Tl.DrawLatex(x1, y, "#Rgothic")        ; Tl.DrawText(x2, y, "#Rgothic");
   y -= step ; Tl.DrawLatex(x1, y, "#GT")             ; Tl.DrawText(x2, y, "#GT");
   y -= step ; Tl.DrawLatex(x1, y, "#propto")         ; Tl.DrawText(x2, y, "#propto");
   y -= step ; Tl.DrawLatex(x1, y, "#notsubset")      ; Tl.DrawText(x2, y, "#notsubset");
   y -= step ; Tl.DrawLatex(x1, y, "#oslash")         ; Tl.DrawText(x2, y, "#oslash");
   y -= step ; Tl.DrawLatex(x1, y, "#vee")            ; Tl.DrawText(x2, y, "#vee");
   y -= step ; Tl.DrawLatex(x1, y, "#void1")          ; Tl.DrawText(x2, y, "#void1");

   // Draw Fith Column
   y = 0.96; x1 = 0.82; x2 = x1+0.04;
               Tl.DrawLatex(x1, y, "#aa")             ; Tl.DrawText(x2, y, "#aa");
   y -= step ; Tl.DrawLatex(x1, y, "#/")              ; Tl.DrawText(x2, y, "#/");
   y -= step ; Tl.DrawLatex(x1, y, "#backslash")      ; Tl.DrawText(x2, y, "#backslash");
   y -= step ; Tl.DrawLatex(x1, y, "#upoint")         ; Tl.DrawText(x2, y, "#upoint");
   y -= step ; Tl.DrawLatex(x1, y, "#partial")        ; Tl.DrawText(x2, y, "#partial");
   y -= step ; Tl.DrawLatex(x1, y, "#corner")         ; Tl.DrawText(x2, y, "#corner");
   y -= step ; Tl.DrawLatex(x1, y, "#ltbar")          ; Tl.DrawText(x2, y, "#ltbar");
   y -= step ; Tl.DrawLatex(x1, y, "#bottombar")      ; Tl.DrawText(x2, y, "#bottombar");
   y -= step ; Tl.DrawLatex(x1, y, "#rightarrow")     ; Tl.DrawText(x2, y, "#rightarrow");
   y -= step ; Tl.DrawLatex(x1, y, "#surd")           ; Tl.DrawText(x2, y, "#surd");
   y -= step ; Tl.DrawLatex(x1, y, "#Rightarrow")     ; Tl.DrawText(x2, y, "#Rightarrow");
   y -= step ; Tl.DrawLatex(x1, y-0.015, "#int")      ; Tl.DrawText(x2, y, "#int");
   y -= step ; Tl.DrawLatex(x1, y, "#odot")           ; Tl.DrawText(x2, y, "#odot");
   y -= step ; Tl.DrawLatex(x1, y, "#exists")         ; Tl.DrawText(x2, y, "#exists");
   y -= step ; Tl.DrawLatex(x1, y, "#plus")           ; Tl.DrawText(x2, y, "#plus");
   y -= step ; Tl.DrawLatex(x1, y, "#minus")          ; Tl.DrawText(x2, y, "#minus");

   return Ms;
}


Delimiters

TLatex provides 4 kinds of proportional delimiters:

   #[]{....} or "a la" Latex #left[.....#right] : big square brackets
   #{}{....} or              #left{.....#right} : big curly brackets
   #||{....} or              #left|.....#right| : big absolute value symbols
   #(){....} or              #left(.....#right) : big parentheses



Greek Letters

The command to produce a lowercase Greek letter is obtained by adding a
# to the name of the letter. For an uppercase Greek letter, just
capitalize the first letter of the command name. Some letters have two
representations. The name of the second one (the "variation") starts with "var".
The following table gives the complete list:


Picture
Source



output of html600/MACRO_TLatex_23.gif


TCanvas *greekletters()
{
   TCanvas *Gl = new TCanvas("greek","greek",500,700);

   TLatex Tl;
   Tl.SetTextSize(0.03);

   // Draw the columns titles
   Tl.SetTextAlign(22);
   Tl.DrawLatex(0.165, 0.95, "Lower case");
   Tl.DrawLatex(0.495, 0.95, "Upper case");
   Tl.DrawLatex(0.825, 0.95, "Variations");

   // Draw the lower case letters
   Tl.SetTextAlign(12);
   float y, x1, x2;
   y = 0.90; x1 = 0.07; x2 = x1+0.2;
                 Tl.DrawLatex(x1, y, "alpha : ")   ; Tl.DrawLatex(x2, y, "#alpha");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "beta : ")    ; Tl.DrawLatex(x2, y, "#beta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "gamma : ")   ; Tl.DrawLatex(x2, y, "#gamma");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "delta : ")   ; Tl.DrawLatex(x2, y, "#delta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "epsilon : ") ; Tl.DrawLatex(x2, y, "#epsilon");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "zeta : ")    ; Tl.DrawLatex(x2, y, "#zeta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "eta : ")     ; Tl.DrawLatex(x2, y, "#eta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "theta : ")   ; Tl.DrawLatex(x2, y, "#theta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "iota : ")    ; Tl.DrawLatex(x2, y, "#iota");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "kappa : ")   ; Tl.DrawLatex(x2, y, "#kappa");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "lambda : ")  ; Tl.DrawLatex(x2, y, "#lambda");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "mu : ")      ; Tl.DrawLatex(x2, y, "#mu");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "nu : ")      ; Tl.DrawLatex(x2, y, "#nu");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "xi : ")      ; Tl.DrawLatex(x2, y, "#xi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "omicron : ") ; Tl.DrawLatex(x2, y, "#omicron");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "pi : ")      ; Tl.DrawLatex(x2, y, "#pi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "rho : ")     ; Tl.DrawLatex(x2, y, "#rho");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "sigma : ")   ; Tl.DrawLatex(x2, y, "#sigma");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "tau : ")     ; Tl.DrawLatex(x2, y, "#tau");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "upsilon : ") ; Tl.DrawLatex(x2, y, "#upsilon");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "phi : ")     ; Tl.DrawLatex(x2, y, "#phi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "chi : ")     ; Tl.DrawLatex(x2, y, "#chi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "psi : ")     ; Tl.DrawLatex(x2, y, "#psi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "omega : ")   ; Tl.DrawLatex(x2, y, "#omega");

   // Draw the upper case letters
   y = 0.90; x1 = 0.40; x2 = x1+0.2;
                 Tl.DrawLatex(x1, y, "Alpha : ")   ; Tl.DrawLatex(x2, y, "#Alpha");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Beta : ")    ; Tl.DrawLatex(x2, y, "#Beta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Gamma : ")   ; Tl.DrawLatex(x2, y, "#Gamma");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Delta : ")   ; Tl.DrawLatex(x2, y, "#Delta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Epsilon : ") ; Tl.DrawLatex(x2, y, "#Epsilon");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Zeta : ")    ; Tl.DrawLatex(x2, y, "#Zeta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Eta : ")     ; Tl.DrawLatex(x2, y, "#Eta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Theta : ")   ; Tl.DrawLatex(x2, y, "#Theta");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Iota : ")    ; Tl.DrawLatex(x2, y, "#Iota");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Kappa : ")   ; Tl.DrawLatex(x2, y, "#Kappa");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Lambda : ")  ; Tl.DrawLatex(x2, y, "#Lambda");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Mu : ")      ; Tl.DrawLatex(x2, y, "#Mu");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Nu : ")      ; Tl.DrawLatex(x2, y, "#Nu");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Xi : ")      ; Tl.DrawLatex(x2, y, "#Xi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Omicron : ") ; Tl.DrawLatex(x2, y, "#Omicron");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Pi : ")      ; Tl.DrawLatex(x2, y, "#Pi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Rho : ")     ; Tl.DrawLatex(x2, y, "#Rho");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Sigma : ")   ; Tl.DrawLatex(x2, y, "#Sigma");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Tau : ")     ; Tl.DrawLatex(x2, y, "#Tau");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Upsilon : ") ; Tl.DrawLatex(x2, y, "#Upsilon");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Phi : ")     ; Tl.DrawLatex(x2, y, "#Phi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Chi : ")     ; Tl.DrawLatex(x2, y, "#Chi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Psi : ")     ; Tl.DrawLatex(x2, y, "#Psi");
   y -= 0.0375 ; Tl.DrawLatex(x1, y, "Omega : ")   ; Tl.DrawLatex(x2, y, "#Omega");

   // Draw the variations
   x1 = 0.73; x2 = x1+0.2;
   y = 0.7500 ; Tl.DrawLatex(x1, y, "varepsilon : ") ; Tl.DrawLatex(x2, y, "#varepsilon");
   y = 0.6375 ; Tl.DrawLatex(x1, y, "vartheta : ")   ; Tl.DrawLatex(x2, y, "#vartheta");
   y = 0.2625 ; Tl.DrawLatex(x1, y, "varsigma : ")   ; Tl.DrawLatex(x2, y, "#varsigma");
   y = 0.1875 ; Tl.DrawLatex(x1, y, "varUpsilon : ") ; Tl.DrawLatex(x2, y, "#varUpsilon");
   y = 0.1500 ; Tl.DrawLatex(x1, y, "varphi : ")     ; Tl.DrawLatex(x2, y, "#varphi");
   y = 0.0375 ; Tl.DrawLatex(x1, y, "varomega : ")   ; Tl.DrawLatex(x2, y, "#varomega");

   return Gl;
}


Accents

Several kind of accents are available:

   #hat    = #hat{a}
   #check  = #check{a}
   #acute  = #acute{a}
   #grave  = #grave{a}
   #dot    = #dot{a}
   #ddot   = #ddot{a}
   #tilde  = #tilde{a}


The special sign: #slash draws a slash on top of the text between brackets:

   #slash{E}_{T} : #slash{E}_{T}


Bar and vectors sign are done the following way:

   #bar{a}: #bar{a}
   #vec{a}: #vec{a}


Changing Style

One can change the font, the text color, or the text size at any time using :
#font[font-number]{...}, #color[color-number]{...}
and #scale[scale-factor]{...}

Examples:

   #font[12]{Times Italic} and #font[22]{Times bold} : #font[12]{Times Italic} and #font[22]{Times bold}
   #color[2]{Red} and #color[4]{Blue} : #color[2]{Red} and #color[4]{Blue}
   #scale[1.2]{Bigger} and #scale[0.8]{Smaller} : #scale[1.2]{Bigger} and #scale[0.8]{Smaller}


Alignment Rules

The TText alignment rules apply to the TLatex objects with one exception
concerning the vertical alignment:

    

  •  if the vertical alignment = 1 , subscripts are not taken into account 
    • 

  •  if the vertical alignment = 0 , the text is aligned to the box surrounding
                                     the full text with sub and superscripts
    • 


This is illustrated by the following example:


Picture
Source



output of html600/MACRO_TLatex_42.gif


{
   TCanvas Tlva("Tlva","Tlva",500,500);
   Tlva.SetGrid();
   Tlva.DrawFrame(0,0,1,1);
   const char *longstring = "K_{S}... K^{*0}... #frac{2s}{#pi#alpha^{2}} #frac{d#sigma}{dcos#theta} (e^{+}e^{-} #rightarrow f#bar{f} ) = #left| #frac{1}{1 - #Delta#alpha} #right|^{2} (1+cos^{2}#theta)";

   TLatex latex;
   latex.SetTextSize(0.025);
   latex.SetTextAlign(13);  //align at top
   latex.DrawLatex(.2,.9,"K_{S}");
   latex.DrawLatex(.3,.9,"K^{*0}");
   latex.DrawLatex(.2,.8,longstring);

   latex.SetTextAlign(12);  //centered
   latex.DrawLatex(.2,.6,"K_{S}");
   latex.DrawLatex(.3,.6,"K^{*0}");
   latex.DrawLatex(.2,.5,longstring);

   latex.SetTextAlign(11);  //default bottom alignment
   latex.DrawLatex(.2,.4,"K_{S}");
   latex.DrawLatex(.3,.4,"K^{*0}");
   latex.DrawLatex(.2,.3,longstring);

   latex.SetTextAlign(10);  //special bottom alignment
   latex.DrawLatex(.2,.2,"K_{S}");
   latex.DrawLatex(.3,.2,"K^{*0}");
   latex.DrawLatex(.2,.1,longstring);

   latex.SetTextAlign(12);
   latex.SetTextFont(72);
   latex.DrawLatex(.1,.80,"13");
   latex.DrawLatex(.1,.55,"12");
   latex.DrawLatex(.1,.35,"11");
   latex.DrawLatex(.1,.18,"10");
   return Tlva;
}


Character Adjustement

The two commands #kern and #lower enable a better control
over character placement. The command #kern[(Float_t)dx]{text} moves
the output string horizontally by the fraction dx of its length.
Similarly, #lower[(Float_t)dy]{text} shifts the text up or down by
the fraction dy of its height.

Examples:

Positive k#kern[0.3]{e}#kern[0.3]{r}#kern[0.3]{n}#kern[0.3]{i}#kern[0.3]{n}#kern[0.3]{g}:
Positive k#kern[0.3]{e}#kern[0.3]{r}#kern[0.3]{n}#kern[0.3]{i}#kern[0.3]{n}#kern[0.3]{g}

Negative k#kern[-0.3]{e}#kern[-0.3]{r}#kern[-0.3]{n}#kern[-0.3]{i}#kern[-0.3]{n}#kern[-0.3]{g}:
Negative k#kern[-0.3]{e}#kern[-0.3]{r}#kern[-0.3]{n}#kern[-0.3]{i}#kern[-0.3]{n}#kern[-0.3]{g}

Vertical a#lower[0.2]{d}#lower[0.4]{j}#lower[0.1]{u}#lower[-0.1]{s}#lower[-0.3]{t}#lower[-0.4]{m}#lower[-0.2]{e}#lower[0.1]{n}t:
Vertical a#lower[0.2]{d}#lower[0.4]{j}#lower[0.1]{u}#lower[-0.1]{s}#lower[-0.3]{t}#lower[-0.4]{m}#lower[-0.2]{e}#lower[0.1]{n}t


Italic and Boldface

Text can be turned italic or boldface using the commands
#it and #bf.

Examples:

#bf{bold}, #it{italic}, #bf{#it{bold italic}}, #bf{#bf{unbold}}}:
#bf{bold}, #it{italic}, #bf{#it{bold italic}}, #bf{#bf{unbold}}

abc#alpha#beta#gamma, #it{abc#alpha#beta#gamma}:
abc#alpha#beta#gamma, #it{abc#alpha#beta#gamma}


Examples



Picture
Source



output of html600/MACRO_TLatex_51.gif


{
   TCanvas ex1("ex1","Latex",500,600);
   TLatex Tl;
   Tl.SetTextAlign(12);
   Tl.SetTextSize(0.04);
   Tl.DrawLatex(0.1,0.8,"1)   C(x) = d #sqrt{#frac{2}{#lambdaD}}  #int^{x}_{0}cos(#frac{#pi}{2}t^{2})dt");
   Tl.DrawLatex(0.1,0.6,"2)   C(x) = d #sqrt{#frac{2}{#lambdaD}}  #int^{x}cos(#frac{#pi}{2}t^{2})dt");
   Tl.DrawLatex(0.1,0.4,"3)   R = |A|^{2} = #frac{1}{2}(#[]{#frac{1}{2}+C(V)}^{2}+#[]{#frac{1}{2}+S(V)}^{2})");
   Tl.DrawLatex(0.1,0.2,"4)   F(t) = #sum_{i=-#infty}^{#infty}A(i)cos#[]{#frac{i}{t+i}}");
   return ex1;
}

Picture
Source



output of html600/MACRO_TLatex_52.gif


{
   TCanvas ex2("ex2","Latex",500,300);
   TLatex Tl;
   Tl.SetTextAlign(23);
   Tl.SetTextSize(0.08);
   Tl.DrawLatex(0.5,0.95,"e^{+}e^{-}#rightarrowZ^{0}#rightarrowI#bar{I}, q#bar{q}");
   Tl.DrawLatex(0.5,0.75,"|#vec{a}#bullet#vec{b}|=#Sigmaa^{i}_{jk}+b^{bj}_{i}");
   Tl.DrawLatex(0.5,0.5,"i(#partial_{#mu}#bar{#psi}#gamma^{#mu}+m#bar{#psi}=0#Leftrightarrow(#Box+m^{2})#psi=0");
   Tl.DrawLatex(0.5,0.3,"L_{em}=eJ^{#mu}_{em}A_{#mu} , J^{#mu}_{em}=#bar{I}#gamma_{#mu}I , M^{j}_{i}=#SigmaA_{#alpha}#tau^{#alphaj}_{i}");
   return ex2;
}

Picture
Source



output of html600/MACRO_TLatex_53.gif


{
   TCanvas ex3("ex3","Latex",500,300);
   TPaveText pt(.1,.1,.9,.9);
   pt.AddText("#frac{2s}{#pi#alpha^{2}}  #frac{d#sigma}{dcos#theta} (e^{+}e^{-} #rightarrow f#bar{f} ) = ");
   pt.AddText("#left| #frac{1}{1 - #Delta#alpha} #right|^{2} (1+cos^{2}#theta");
   pt.AddText("+ 4 Re #left{ #frac{2}{1 - #Delta#alpha} #chi(s) #[]{#hat{g}_{#nu}^{e}#hat{g}_{#nu}^{f} (1 + cos^{2}#theta) + 2 #hat{g}_{a}^{e}#hat{g}_{a}^{f} cos#theta) } #right}");
   pt.SetLabel("Born equation");
   pt.Draw();
   return ex3;
}


Interface to TMathText

The class TMathText is a TeX math formulae interpreter. It uses plain
TeX syntax and uses "\" as control instead of "#". If a piece of text containing
"\" is given to TLatex then TMathText is automatically invoked.
Therefore, as histograms' titles, axis titles, labels etc ... are drawn using
TLatex, the TMathText syntax can be used for them also.










Function Members (Methods)


public:



 virtual~TLatex()


voidTObject::AbstractMethod(const char* method) const


virtual voidTObject::AppendPad(Option_t* option = "")


virtual voidTObject::Browse(TBrowser* b)


static TClass*Class()


virtual const char*TObject::ClassName() const


virtual voidTNamed::Clear(Option_t* option = "")


virtual TObject*TNamed::Clone(const char* newname = "") const


virtual Int_tTNamed::Compare(const TObject* obj) const


virtual voidCopy(TObject& text) const


virtual voidTObject::Delete(Option_t* option = "")MENU 


Int_tTAttLine::DistancetoLine(Int_t px, Int_t py, Double_t xp1, Double_t yp1, Double_t xp2, Double_t yp2)


virtual Int_tTText::DistancetoPrimitive(Int_t px, Int_t py)


virtual voidTObject::Draw(Option_t* option = "")


virtual voidTObject::DrawClass() constMENU 


virtual TObject*TObject::DrawClone(Option_t* option = "") constMENU 


TLatex*DrawLatex(Double_t x, Double_t y, const char* text)


TLatex*DrawLatexNDC(Double_t x, Double_t y, const char* text)


virtual TText*TText::DrawText(Double_t x, Double_t y, const char* text)


virtual TText*TText::DrawText(Double_t x, Double_t y, const wchar_t* text)


virtual TText*TText::DrawTextNDC(Double_t x, Double_t y, const char* text)


virtual TText*TText::DrawTextNDC(Double_t x, Double_t y, const wchar_t* text)


virtual voidTObject::Dump() constMENU 


virtual voidTObject::Error(const char* method, const char* msgfmt) const


virtual voidTObject::Execute(const char* method, const char* params, Int_t* error = 0)


virtual voidTObject::Execute(TMethod* method, TObjArray* params, Int_t* error = 0)


virtual voidTText::ExecuteEvent(Int_t event, Int_t px, Int_t py)


virtual voidTObject::Fatal(const char* method, const char* msgfmt) const


virtual voidTNamed::FillBuffer(char*& buffer)


virtual TObject*TObject::FindObject(const char* name) const


virtual TObject*TObject::FindObject(const TObject* obj) const


virtual Rectangle_tTText::GetBBox()


virtual TPointTText::GetBBoxCenter()


virtual voidGetBoundingBox(UInt_t& w, UInt_t& h, Bool_t angle = kFALSE)


virtual voidTText::GetControlBox(Int_t x, Int_t y, Double_t theta, Int_t[4] cBoxX, Int_t[4] cBoxY)


virtual Option_t*TObject::GetDrawOption() const


static Long_tTObject::GetDtorOnly()


Double_tGetHeight() const


virtual const char*TObject::GetIconName() const


virtual Color_tTAttLine::GetLineColor() const


virtual Style_tTAttLine::GetLineStyle() const


virtual Width_tTAttLine::GetLineWidth() const


virtual const char*TNamed::GetName() const


virtual char*TObject::GetObjectInfo(Int_t px, Int_t py) const


static Bool_tTObject::GetObjectStat()


virtual Option_t*TObject::GetOption() const


virtual voidTText::GetTextAdvance(UInt_t& a, const char* text, const Bool_t kern = kTRUE) const


virtual Short_tTAttText::GetTextAlign() const


virtual Float_tTAttText::GetTextAngle() const


virtual voidTText::GetTextAscentDescent(UInt_t& a, UInt_t& d, const char* text) const


virtual voidTText::GetTextAscentDescent(UInt_t& a, UInt_t& d, const wchar_t* text) const


virtual Color_tTAttText::GetTextColor() const


virtual voidTText::GetTextExtent(UInt_t& w, UInt_t& h, const char* text) const


virtual voidTText::GetTextExtent(UInt_t& w, UInt_t& h, const wchar_t* text) const


virtual Font_tTAttText::GetTextFont() const


virtual Float_tTAttText::GetTextSize() const


virtual const char*TNamed::GetTitle() const


virtual UInt_tTObject::GetUniqueID() const


const void*TText::GetWcsTitle() const


Double_tTText::GetX() const


Double_tGetXsize()


Double_tTText::GetY() const


Double_tGetYsize()


virtual Bool_tTObject::HandleTimer(TTimer* timer)


virtual ULong_tTNamed::Hash() const


virtual voidTObject::Info(const char* method, const char* msgfmt) const


virtual Bool_tTObject::InheritsFrom(const char* classname) const


virtual Bool_tTObject::InheritsFrom(const TClass* cl) const


virtual voidTObject::Inspect() constMENU 


voidTObject::InvertBit(UInt_t f)


virtual TClass*IsA() const


virtual Bool_tTObject::IsEqual(const TObject* obj) const


virtual Bool_tTObject::IsFolder() const


Bool_tTObject::IsOnHeap() const


virtual Bool_tTNamed::IsSortable() const


Bool_tTObject::IsZombie() const


virtual voidTText::ls(Option_t* option = "") const


voidTObject::MayNotUse(const char* method) const


virtual voidTAttText::Modify()


virtual Bool_tTObject::Notify()


voidTObject::Obsolete(const char* method, const char* asOfVers, const char* removedFromVers) const


voidTObject::operator delete(void* ptr)


voidTObject::operator delete(void* ptr, void* vp)


voidTObject::operator delete[](void* ptr)


voidTObject::operator delete[](void* ptr, void* vp)


void*TObject::operator new(size_t sz)


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


void*TObject::operator new[](size_t sz)


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


virtual voidPaint(Option_t* option = "")


virtual voidTText::PaintControlBox(Int_t x, Int_t y, Double_t theta)


virtual voidPaintLatex(Double_t x, Double_t y, Double_t angle, Double_t size, const char* text)


virtual voidTText::PaintText(Double_t x, Double_t y, const char* text)


virtual voidTText::PaintText(Double_t x, Double_t y, const wchar_t* text)


virtual voidTText::PaintTextNDC(Double_t u, Double_t v, const char* text)


virtual voidTText::PaintTextNDC(Double_t u, Double_t v, const wchar_t* text)


virtual voidTObject::Pop()


virtual voidTText::Print(Option_t* option = "") const


virtual Int_tTObject::Read(const char* name)


virtual voidTObject::RecursiveRemove(TObject* obj)


virtual voidTAttLine::ResetAttLine(Option_t* option = "")


virtual voidTAttText::ResetAttText(Option_t* toption = "")


voidTObject::ResetBit(UInt_t f)


virtual voidTObject::SaveAs(const char* filename = "", Option_t* option = "") constMENU 


virtual voidTAttLine::SaveLineAttributes(ostream& out, const char* name, Int_t coldef = 1, Int_t stydef = 1, Int_t widdef = 1)


virtual voidSavePrimitive(ostream& out, Option_t* option = "")


virtual voidTAttText::SaveTextAttributes(ostream& out, const char* name, Int_t alidef = 12, Float_t angdef = 0, Int_t coldef = 1, Int_t fondef = 61, Float_t sizdef = 1)


virtual voidTText::SetBBoxCenter(const TPoint& p)


virtual voidTText::SetBBoxCenterX(const Int_t x)


virtual voidTText::SetBBoxCenterY(const Int_t y)


virtual voidTText::SetBBoxX1(const Int_t x)


virtual voidTText::SetBBoxX2(const Int_t x)


virtual voidTText::SetBBoxY1(const Int_t y)


virtual voidTText::SetBBoxY2(const Int_t y)


voidTObject::SetBit(UInt_t f)


voidTObject::SetBit(UInt_t f, Bool_t set)


virtual voidTObject::SetDrawOption(Option_t* option = "")MENU 


static voidTObject::SetDtorOnly(void* obj)


virtual voidSetIndiceSize(Double_t factorSize)


virtual voidSetLimitIndiceSize(Int_t limitFactorSize)


virtual voidTAttLine::SetLineAttributes()MENU 


virtual voidTAttLine::SetLineColor(Color_t lcolor)


virtual voidTAttLine::SetLineColorAlpha(Color_t lcolor, Float_t lalpha)


virtual voidTAttLine::SetLineStyle(Style_t lstyle)


virtual voidTAttLine::SetLineWidth(Width_t lwidth)


virtual voidTText::SetMbTitle(const wchar_t* title = L"")MENU 


virtual voidTNamed::SetName(const char* name)MENU 


virtual voidTNamed::SetNameTitle(const char* name, const char* title)


virtual voidTText::SetNDC(Bool_t isNDC = kTRUE)


static voidTObject::SetObjectStat(Bool_t stat)


virtual voidTText::SetText(Double_t x, Double_t y, const char* text)MENU 


virtual voidTText::SetText(Double_t x, Double_t y, const wchar_t* text)


virtual voidTAttText::SetTextAlign(Short_t align = 11)


virtual voidTAttText::SetTextAngle(Float_t tangle = 0)MENU 


virtual voidTAttText::SetTextAttributes()MENU 


virtual voidTAttText::SetTextColor(Color_t tcolor = 1)


virtual voidTAttText::SetTextColorAlpha(Color_t tcolor, Float_t talpha)


virtual voidTAttText::SetTextFont(Font_t tfont = 62)


virtual voidTAttText::SetTextSize(Float_t tsize = 1)


virtual voidTAttText::SetTextSizePixels(Int_t npixels)


virtual voidTNamed::SetTitle(const char* title = "")MENU 


virtual voidTObject::SetUniqueID(UInt_t uid)


virtual voidTText::SetX(Double_t x)MENU 


virtual voidTText::SetY(Double_t y)MENU 


virtual voidShowMembers(TMemberInspector& insp) const


virtual Int_tTNamed::Sizeof() const


virtual voidStreamer(TBuffer&)


voidStreamerNVirtual(TBuffer& ClassDef_StreamerNVirtual_b)


virtual voidTObject::SysError(const char* method, const char* msgfmt) const


Bool_tTObject::TestBit(UInt_t f) const


Int_tTObject::TestBits(UInt_t f) const


TLatex()


TLatex(const TLatex& text)


TLatex(Double_t x, Double_t y, const char* text)


virtual voidTObject::UseCurrentStyle()


virtual voidTObject::Warning(const char* method, const char* msgfmt) const


virtual Int_tTObject::Write(const char* name = 0, Int_t option = 0, Int_t bufsize = 0)


virtual Int_tTObject::Write(const char* name = 0, Int_t option = 0, Int_t bufsize = 0) const





protected:



TLatexFormSizeAnal1(TextSpec_t spec, const Char_t* t, Int_t length)


TLatexFormSizeAnalyse(Double_t x, Double_t y, TextSpec_t spec, const Char_t* t, Int_t length)


Int_tCheckLatexSyntax(TString& text)


virtual voidTObject::DoError(int level, const char* location, const char* fmt, va_list va) const


voidDrawCircle(Double_t x1, Double_t y1, Double_t r, TextSpec_t spec)


voidDrawLine(Double_t x1, Double_t y1, Double_t x2, Double_t y2, TextSpec_t spec)


voidDrawParenthesis(Double_t x1, Double_t y1, Double_t r1, Double_t r2, Double_t phimin, Double_t phimax, TextSpec_t spec)


TLatexFormSizeFirstParse(Double_t angle, Double_t size, const Char_t* text)


voidTObject::MakeZombie()


TLatex&operator=(const TLatex&)


TLatexFormSizeReadfs()


voidSavefs(TLatexFormSize* fs)










Data Members


public:



static TObject::<anonymous>TObject::kBitMask


static TObject::EStatusBitsTObject::kCanDelete


static TObject::EStatusBitsTObject::kCannotPick


static TObject::EStatusBitsTObject::kHasUUID


static TObject::EStatusBitsTObject::kInvalidObject


static TObject::<anonymous>TObject::kIsOnHeap


static TObject::EStatusBitsTObject::kIsReferenced


static TObject::EStatusBitsTObject::kMustCleanup


static TObject::EStatusBitsTObject::kNoContextMenu


static TObject::<anonymous>TObject::kNotDeleted


static TObject::EStatusBitsTObject::kObjInCanvas


static TObject::<anonymous>TObject::kOverwrite


static TObject::<anonymous>TObject::kSingleKey


static TLatex::<anonymous>kTextNDC


static TText::<anonymous>TText::kTextNDC


static TObject::<anonymous>TObject::kWriteDelete


static TObject::<anonymous>TObject::kZombie





protected:



const Char_t*fError!error code


Double_tfFactorPos!Relative position of subscripts and superscripts


Double_tfFactorSize!Relative size of subscripts and superscripts


Bool_tfItalic!Currently inside #it operator


Int_tfLimitFactorSizelower bound for subscripts/superscripts size


Color_tTAttLine::fLineColorline color


Style_tTAttLine::fLineStyleline style


Width_tTAttLine::fLineWidthline width


TStringTNamed::fNameobject identifier


Double_tfOriginSizeFont size of the starting font


Int_tfPos!Current position in array fTabSize;


Bool_tfShow!is true during the second pass (Painting)


Int_tfTabMax!Maximum allocation for array fTabSize;


FormSize_t*fTabSize!array of values for the different zones


Short_tTAttText::fTextAlignText alignment


Float_tTAttText::fTextAngleText angle


Color_tTAttText::fTextColorText color index


Font_tTAttText::fTextFontText font number


Float_tTAttText::fTextSizeText size


TStringTNamed::fTitleobject title


void*TText::fWcsTitle!Used by TMathText


Double_tTText::fXX position of text (left,center,etc..)


Double_tTText::fYY position of text (left,center,etc..)







Class Charts

























































Inheritance
Inherited Members
Includes
Libraries



Class Charts


Function documentation


 TLatex()


 Default constructor.





 TLatex(Double_t x, Double_t y, const char* text)


 Normal constructor.





 ~TLatex()


 Destructor.





 TLatex(const TLatex& text)


 Copy constructor.





TLatex& operator=(const TLatex& )


assignment operator





void Copy(TObject& text) const


 Copy this TLatex object to another TLatex.





TLatexFormSize Anal1(TextSpec_t spec, const Char_t* t, Int_t length)


 Analyse function.





TLatexFormSize Analyse(Double_t x, Double_t y, TextSpec_t spec, const Char_t* t, Int_t length)


  Analyse and paint the TLatex formula

  It is called twice : first for calculating the size of
  each portion of the formula, then to paint the formula.
  When analyse finds an operator or separator, it calls
  itself recursively to analyse the arguments of the operator.
  when the argument is an atom (normal text), it calculates
  the size of it and return it as the result.
  for example : if the operator #frac{arg1}{arg2} is found :
  Analyse(arg1) return the size of arg1 (width, up, down)
  Analyse(arg2) return the size of arg2
  now, we know the size of #frac{arg1}{arg2}  :
  width = max(width_arg1, width_arg2)
  up = up_arg1 + down_arg1
  down = up_arg2 + down_arg2
  so, when the user wants to paint a fraction at position (x,y),
  the rect used for the formula is : (x,y-up,x+width,y+down)

 return size of zone occupied by the text/formula
 t : chain to be analyzed
 length : number of chars in t.





TLatex * DrawLatex(Double_t x, Double_t y, const char* text)


 Make a copy of this object with the new parameters
 And copy object attributes





TLatex * DrawLatexNDC(Double_t x, Double_t y, const char* text)


 Draw this TLatex with new coordinates in NDC.





void DrawLine(Double_t x1, Double_t y1, Double_t x2, Double_t y2, TextSpec_t spec)


 Draw a line in a Latex formula





void DrawCircle(Double_t x1, Double_t y1, Double_t r, TextSpec_t spec)


 Draw an arc of ellipse in a Latex formula (right or left parenthesis)





void DrawParenthesis(Double_t x1, Double_t y1, Double_t r1, Double_t r2, Double_t phimin, Double_t phimax, TextSpec_t spec)


 Draw an arc of ellipse in a Latex formula (right or left parenthesis)





void Paint(Option_t* option = "")


 Paint.





void PaintLatex(Double_t x, Double_t y, Double_t angle, Double_t size, const char* text)


 Main drawing function

 Warning: Unlike most others "XYZ::PaintXYZ" methods, PaintLatex modifies
          the TLatex data members.





Int_t CheckLatexSyntax(TString& text)


 Check if the Latex syntax is correct





TLatexFormSize FirstParse(Double_t angle, Double_t size, const Char_t* text)


 First parsing of the analyse sequence





Double_t GetHeight() const


 Return height of current pad in pixels





Double_t GetXsize()


 Return size of the formula along X in pad coordinates





void GetBoundingBox(UInt_t& w, UInt_t& h, Bool_t angle = kFALSE)


 Return text size in pixels





Double_t GetYsize()


 Return size of the formula along Y in pad coordinates





TLatexFormSize Readfs()


 Read fs in fTabSize





void Savefs(TLatexFormSize* fs)


 Save fs values in array fTabSize





void SavePrimitive(ostream& out, Option_t* option = "")


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





void SetIndiceSize(Double_t factorSize)


 Set relative size of subscripts and superscripts





void SetLimitIndiceSize(Int_t limitFactorSize)


 Set limit for text resizing of subscipts and superscripts