diff options
Diffstat (limited to 'buch/papers/ellfilter/python/elliptic2.py')
| -rw-r--r-- | buch/papers/ellfilter/python/elliptic2.py | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/buch/papers/ellfilter/python/elliptic2.py b/buch/papers/ellfilter/python/elliptic2.py index 29c6f47..cfa16ea 100644 --- a/buch/papers/ellfilter/python/elliptic2.py +++ b/buch/papers/ellfilter/python/elliptic2.py @@ -1,5 +1,6 @@ # %% +import enum import matplotlib.pyplot as plt import scipy.signal import numpy as np @@ -8,7 +9,9 @@ from matplotlib.patches import Rectangle import plot_params -def ellip_filter(N): +N=5 + +def ellip_filter(N, mode=-1): order = N passband_ripple_db = 3 @@ -26,7 +29,16 @@ def ellip_filter(N): fs=None ) - w, mag_db, phase = scipy.signal.bode((a, b), w=np.linspace(0*omega_c,2*omega_c, 4000)) + if mode == 0: + w = np.linspace(0*omega_c,omega_c, 2000) + elif mode == 1: + w = np.linspace(omega_c,1.00992*omega_c, 2000) + elif mode == 2: + w = np.linspace(1.00992*omega_c,2*omega_c, 2000) + else: + w = np.linspace(0*omega_c,2*omega_c, 4000) + + w, mag_db, phase = scipy.signal.bode((a, b), w=w) mag = 10**(mag_db/20) @@ -40,9 +52,9 @@ def ellip_filter(N): plt.figure(figsize=(4,2.5)) -for N in [5]: - w, FN2, mag, a, b = ellip_filter(N) - plt.semilogy(w, FN2, label=f"$N={N}, k=0.1$", linewidth=1) +for mode, c in enumerate(["green", "orange", "red"]): + w, FN2, mag, a, b = ellip_filter(N, mode=mode) + plt.semilogy(w, FN2, label=f"$N={N}, k=0.1$", linewidth=1, color=c) plt.gca().add_patch(Rectangle( (0, 0), @@ -53,21 +65,21 @@ plt.gca().add_patch(Rectangle( )) plt.gca().add_patch(Rectangle( (1, 1), - 0.01, 1e2-1, + 0.00992, 1e2-1, fc ='orange', alpha=0.2, lw = 10, )) plt.gca().add_patch(Rectangle( - (1.01, 100), + (1.00992, 100), 1, 1e6, fc ='red', alpha=0.2, lw = 10, )) -zeros = [0,0.87,1] +zeros = [0,0.87,0.995] poles = [1.01,1.155] import matplotlib.transforms @@ -99,7 +111,7 @@ plt.ylim([1e-4,1e6]) plt.grid() plt.xlabel("$w$") plt.ylabel("$F^2_N(w)$") -plt.legend() +# plt.legend() plt.tight_layout() plt.savefig("F_N_elliptic.pgf") plt.show() @@ -107,7 +119,9 @@ plt.show() plt.figure(figsize=(4,2.5)) -plt.plot(w, mag, linewidth=1) +for mode, c in enumerate(["green", "orange", "red"]): + w, FN2, mag, a, b = ellip_filter(N, mode=mode) + plt.plot(w, mag, linewidth=1, color=c) plt.gca().add_patch(Rectangle( (0, np.sqrt(2)/2), @@ -118,14 +132,14 @@ plt.gca().add_patch(Rectangle( )) plt.gca().add_patch(Rectangle( (1, 0.1), - 0.01, np.sqrt(2)/2 - 0.1, + 0.00992, np.sqrt(2)/2 - 0.1, fc ='orange', alpha=0.2, lw = 10, )) plt.gca().add_patch(Rectangle( - (1.01, 0), + (1.00992, 0), 1, 0.1, fc ='red', alpha=0.2, |