Trying to plot input and output resistance for a single BJT in LTspice
I use this circuit: 



And \$\large r_{e} = \frac{d(V_{BE})}{d(I_E)} \approx \frac{V_T}{I_E} \approx\frac{25.86492 \textrm{mV}}{I_E}\$ plot at \$27^{\circ}C\$



And \$\large r_{\pi}= \frac{d(V_{BE})}{d(I_B)} \approx (\beta +1)r_e\$