edfa model, json config loading, added utils (#26)

examples/edfa/example.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+from gnpy.core.utils import (load_json,
+                             itufs,
+                             freq2wavelength,
+                             lin2db,
+                             db2lin)
+from gnpy.core import network
+
+topology = load_json('edfa_example_network.json')
+nw = network.network_from_json(topology)
+pch2d_legend_data = np.loadtxt('Pchan2DLegend.txt')
+pch2d = np.loadtxt('Pchan2D.txt')
+
+ch_spacing = 0.05
+fc = itufs(ch_spacing)
+lc = freq2wavelength(fc) / 1000
+nchan = np.arange(len(lc))
+df = np.ones(len(lc)) * ch_spacing
+
+edfa1 = [n for n in nw.nodes() if n.uid == 'Edfa1'][0]
+edfa1.gain_target = 20.0
+edfa1.tilt_target = -0.7
+edfa1.calc_nf()
+
+results = []
+for Pin in pch2d:
+    chgain = edfa1.gain_profile(Pin)
+    pase = edfa1.noise_profile(chgain, fc, df)
+    pout = lin2db(db2lin(Pin + chgain) + db2lin(pase))
+    results.append(pout)
+
+# Generate legend text
+
+pch2d_legend = []
+for ea in pch2d_legend_data:
+    s = ''.join([chr(xx) for xx in ea.astype(dtype=int)]).strip()
+    pch2d_legend.append(s)
+
+# Plot
+axis_font = {'fontname': 'Arial', 'size': '16', 'fontweight': 'bold'}
+title_font = {'fontname': 'Arial', 'size': '17', 'fontweight': 'bold'}
+tic_font = {'fontname': 'Arial', 'size': '12'}
+plt.rcParams["font.family"] = "Arial"
+plt.figure()
+plt.plot(nchan, pch2d.T, '.-', lw=2)
+plt.xlabel('Channel Number', **axis_font)
+plt.ylabel('Channel Power [dBm]', **axis_font)
+plt.title('Input Power Profiles for Different Channel Loading', **title_font)
+plt.legend(pch2d_legend, loc=5)
+plt.grid()
+plt.ylim((-100, -10))
+plt.xlim((0, 110))
+plt.xticks(np.arange(0, 100, 10), **tic_font)
+plt.yticks(np.arange(-110, -10, 10), **tic_font)
+plt.figure()
+for result in results:
+    plt.plot(nchan, result, '.-', lw=2)
+plt.title('Output Power w/ ASE for Different Channel Loading', **title_font)
+plt.xlabel('Channel Number', **axis_font)
+plt.ylabel('Channel Power [dBm]', **axis_font)
+plt.grid()
+plt.ylim((-50, 10))
+plt.xlim((0, 100))
+plt.xticks(np.arange(0, 100, 10), **tic_font)
+plt.yticks(np.arange(-50, 10, 10), **tic_font)
+plt.legend(pch2d_legend, loc=5)
+plt.show()