Each great spirit:
I have installed in the Windows system Graphviz, but operates the following statement: in python
Plot_tree (CLF, num_trees=0), the system error is as follows:
ExecutableNotFound: failed to execute [' dot ', '- Tpng], make sure the Graphviz executables are on your systems' PATH
Feel all did all the work, including installing Graphviz, configure the environment variables, don't know where the problem is, grateful for the great god!