doc/v606/formula1_8C.html

void formula1() {

   TCanvas *c1 = new TCanvas("c1","Example with Formula",200,10,700,500);

   //

   // We create a formula object and compute the value of this formula

   // for two different values of the x variable.

   //

   auto form1 = new TFormula("form1","sqrt(abs(x))");

   form1->Eval(2);

   form1->Eval(-45);

   //

   // Create a one dimensional function and draw it

   //

   auto fun1 = new TF1("fun1","abs(sin(x)/x)",0,10);

   c1->SetGridx();

   c1->SetGridy();

   fun1->Draw();

   c1->Update();

   //

   // Before leaving this demo, we print the list of objects known to ROOT

   //

   if (gObjectTable) gObjectTable->Print();

}