#include "TGraphErrors.h" void example() { // Define arrays for x, y, and their errors double x[] = {1.0, 2.0, 3.0, 4.0, 5.0}; double y[] = {1.0, 2.0, 3.0, 4.0, 5.0}; double ey[] = {0.1, 0.2, 0.3, 0.4, 0.5}; // Create a TGraphErrors object with 5 points TGraphErrors graph(5); // Set the coordinates and errors for each point for (int i = 0; i < 5; i++) { graph.SetPoint(i, x[i], y[i], ey[i]); } // Draw the graph graph.Draw("AP"); }In this example, we define arrays for the x and y coordinates, as well as the error in y. We then create a TGraphErrors object with five points, and use the SetPoint function in a loop to set the coordinates and corresponding errors for each point. Finally, we draw the graph with the "AP" option, which specifies that both data points and error bars should be drawn. The package library for TGraphErrors is ROOT, which is a set of C++ libraries for data analysis and visualization. ROOT is commonly used in particle physics experiments, but it can also be used for a wide range of other scientific and engineering applications.