def plot_single_configuration(self, config_nr, sens_file):
        """
        plot sensitivity distribution with center of mass for
        a single configuration. The electrodes used are colored.

        Parameters
        ----------
        config_nr: int
            number of configuration
        sens_file: string, file path
            filename to sensitvity file

        """
        indices = elem.load_column_file_to_elements_advanced(
            sens_file, [2, 3],
            False,
            False
        )

        elem.plt_opt.title = ''
        elem.plt_opt.reverse = True
        elem.plt_opt.cbmin = -1
        elem.plt_opt.cbmax = 1
        elem.plt_opt.cblabel = r'fill'
        elem.plt_opt.xlabel = 'x (m)'
        elem.plt_opt.ylabel = 'z (m)'

        fig = plt.figure(figsize=(5, 7))
        ax = fig.add_subplot(111)
        ax, pm, cb = elem.plot_element_data_to_ax(
            indices[0],
            ax,
            scale='asinh',
            no_cb=False,
        )
        ax.scatter(
            self.sens_centers[config_nr, 0],
            self.sens_centers[config_nr, 1],
            marker='*',
            s=50,
            color='w',
            edgecolors='w',
        )

        self.color_electrodes(config_nr, ax)

        # Output
        sensf = sens_file.split('sens')[-1]
        sensf = sensf.split('.')[0]
        out = 'sens_center_' + sensf + '.png'
        fig.savefig(out, bbox_inches='tight', dpi=300)
        fig.clf()
        plt.close(fig)
plot sensitivity distribution with center of mass for
        a single configuration. The electrodes used are colored.

        Parameters
        ----------
        config_nr: int
            number of configuration
        sens_file: string, file path
            filename to sensitvity file