???

def plot_error_pars(self, mid):
        """ ???

        """
        fig, axes = plt.subplots(1, 2, figsize=(10, 6))

        def plot_error_pars(axes, a, b, R, label=''):
            dR = a * R + b
            dlogR = np.abs(a + b / R)
            ax = axes[0]
            ax.scatter(R, dR / R * 100, label=label)
            ax = axes[1]
            ax.scatter(R, dlogR / np.abs(np.log(R)) * 100, label=label)
            ax.set_xscale('log')
            ax.set_yscale('log')

        for b in np.linspace(R.min(), np.percentile(R, 10), 5):
            plot_error_pars(axes, 0.05, b, R, label='b={0:.4f}'.format(b))
        axes[0].set_xlabel(r'$R [\Omega]$')
        axes[0].set_ylabel(r'$(\Delta R/R) \cdot 100 [\%]$')
        axes[1].set_xlabel(r'$log_{10}(R [\Omega])$')
        axes[1].set_ylabel(
            r'$log_{10}(R) / \Delta log_{10}(R) \cdot 100 [\%]$'
        )
        axes[0].axhline(y=100)
        axes[1].axhline(y=100)
        fig.tight_layout()
        fig.subplots_adjust(bottom=0.2)
        axes[0].legend(
            loc="lower center",
            ncol=4,
            bbox_to_anchor=(0, 0, 1, 1),
            bbox_transform=fig.transFigure
        )

        # fig.savefig('out.png', dpi=300)
        return fig