Summary of Visual effects

Colours and Graph Markers[edit | edit source]

We have seen that to specify a colour, some identifiers like kWhite, kRed or kBlue can be specified for markers, lines, arrows etc. The complete summary of colours is represented by the ROOT "colour wheel". To know more about the full story, refer to the online documentation of TColor.

ROOT provides several graphics markers types. Select the most suited symbols for your plot among dots, triangles, crosses or stars. An alternative set of names for the markers is available.

Arrows and Lines[edit | edit source]

The macro line 55 shows how to define an arrow and draw it. The class representing arrows is TArrow, which inherits from TLine. The constructors of lines and arrows always contain the coordinates of the endpoints. Arrows also foresee parameters to specify their shapes. Do not underestimate the role of lines and arrows in your plots. Since each plot should contain a message, it is convenient to stress it with additional graphics primitives.

Text[edit | edit source]

Also text plays a fundamental role in making the plots self-explanatory. A possibility to add text in your plot is provided by the TLatex class. The objects of this class are constructed with the coordinates of the bottom-left corner of the text and a string which contains the text itself. The real twist is that ordinary Latex mathematical symbols are automatically interpreted, you just need to replace the "\" by a "#".

If "\" is used as control character , then the TMathText interface is invoked. It provides the plain TeX syntax and allow to access character's set like Russian and Japenese.