Add example calling the simulator

Author: RainerKuemmerle

python/examples/simulator.py

@@ -0,0 +1,34 @@
+import g2opy as g2o
+
+simulator = g2o.Simulator2D()
+simulator.config.has_odom = True
+simulator.config.has_pose_sensor = True
+simulator.config.world_size = 50.0
+simulator.config.sim_steps = 500
+
+simulator.setup()
+simulator.simulate()
+
+print("Simulation result")
+print(f"Number of vertices: {len(simulator.graph().vertices())}")
+print(f"Number of edges {len(simulator.graph().edges())}")
+
+
+def create_optimizer():
+    optimizer = g2o.SparseOptimizer()
+    solver = g2o.BlockSolverX(g2o.LinearSolverEigenX())
+    solver = g2o.OptimizationAlgorithmLevenberg(solver)
+    optimizer.set_algorithm(solver)
+    return optimizer
+
+
+optimizer = create_optimizer()
+optimizer.add_graph(simulator.graph())
+print("Optimizer")
+print(f"Number of vertices: {len(optimizer.vertices())}")
+print(f"Number of edges {len(optimizer.edges())}")
+
+optimizer.vertices()[0].set_fixed(True)
+optimizer.initialize_optimization()
+optimizer.set_verbose(True)
+optimizer.optimize(20)