/// \file
/// \ingroup tutorial_graphics
/// \notebook
/// \preview Example illustrating how to modify individual labels of a TGaxis. The method
/// `ChangeLabel` allows to do that.
///
/// The first parameter of this method is the label number to be modified. If
/// this number is negative labels are numbered from the last one. The other
/// parameters are (in order):
///  - the new angle value,
///  - the new size (0 erase the label),
///  - the new text alignment,
///  - the new label color,
///  - the new label text.
///
/// \macro_image
/// \macro_code
///
/// \author  Olivier Couet

void gaxis3()
{
   TCanvas *c1 = new TCanvas("c1", "Examples of TGaxis", 10, 10, 800, 400);
   c1->Range(-6, -0.1, 6, 0.1);

   TGaxis *axis = new TGaxis(-5.5, 0., 5.5, 0., 0.0, 100, 510, "");
   axis->SetName("axis");
   axis->SetTitle("Axis Title");
   axis->SetTitleSize(0.05);
   axis->SetTitleColor(kBlue);
   axis->SetTitleFont(42);

   // Change the  1st label color to red.
   axis->ChangeLabel(1, -1, -1, -1, kRed);

   // Erase the 3rd label
   axis->ChangeLabel(3, -1, 0.);

   // 5th label is drawn with an angle of 30 degrees
   axis->ChangeLabel(5, 30., -1, 0);

   // Change the text of the 6th label.
   axis->ChangeLabel(6, -1, -1, -1, kGreen, -1, "6th label");

   // Change the text of the 2nd label to the end.
   axis->ChangeLabel(-2, -1, -1, -1, kGreen, -1, "2nd to last label");

   // Change the text of value 30 by "value of 30"
   axis->ChangeLabelByValue(30., -1, -1, -1, kBlue, -1, "value of 30");

   axis->Draw();
}
