use threshold argument to matrix_histogram_complex from qpt_plot_combined
use threshold argument to matrix_histogram_complex from qpt_plot_combined

zasdfgbnm/qutip,cgranade/qutip,qutip/qutip,anubhavvardhan/qutip,qutip/qutip,cgranade/qutip,zasdfgbnm/qutip,anubhavvardhan/qutip