update scope mode example

Author: newville

examples/scope_mode_mpl_compare.py

@@ -1,28 +1,28 @@
 # This could be comparable to
 # https://matplotlib.org/stable/gallery/animation/strip_chart.html
 
+from random import random
 import numpy as np
 from wxmplot.interactive import plot, set_data_generator
 
-np.random.seed(19680801 // 10)
-
 class Scope:
     def __init__(self, nmax=50, dt=0.1):
         self.dt = dt
         self.nmax = nmax
-        self.t, self.y = [], []
-        print(nmax, dt)
+        self.tmax = dt*nmax
+        self.t = []
+        self.y = []
 
     def update(self):
-        if len(self.y) > self.nmax:
-            self.t, self.y = [], []
-        self.t.append(self.dt*len(self.y))
-        p = np.random.rand()
-        self.y.append(np.random.rand() if p < 0.15 else 0)
+        n = len(self.y)
+        if n > self.nmax:
+            self.t, self.y, n = [0], [0], 1
+        self.t.append(n*self.dt)
+        self.y.append(random() if random() < 0.15 else 0)
         return [(self.t, self.y)]
 
-NMAX, DT = 200, 0.05
-scope = Scope(nmax=NMAX, dt=DT)
+scope = Scope(nmax=200, dt=0.05)
+
+plotter = plot([0], [0], xmax=scope.tmax, ymin=-0.05, ymax=1.05, drawstyle='steps-mid')
 
-plot([0], [0], xmax=NMAX*DT)
-set_data_generator(scope.update)
+set_data_generator(scope.update, win=plotter.window)