Creates bar chart (log version)

        :param x_labels: Names for each variable
        :param y_values: Values of x labels
        :param y_label: Label of y axis
        :return: Sym-log bar chart

def create_sym_log_bar_chart(self, x_labels, y_values, y_label):
        """Creates bar chart (log version)

        :param x_labels: Names for each variable
        :param y_values: Values of x labels
        :param y_label: Label of y axis
        :return: Sym-log bar chart
        """
        ax1 = self.create_bar_chart(x_labels, y_values, y_label)
        ax1.set_yscale("sym-log", linthreshy=1e-12)  # logarithmic plot
        return ax1