/usr/lib/python2.7/dist-packages/scitools/MovingPlotWindow.py is in python-scitools 0.9.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | """Manage a moving plot window for displaying very long time series."""
import time
class MovingPlotWindow:
'''
Make a plot window that follows the tip (end) of a very long
time series.
Example::
def demo(I, k, dt, T, mode='continuous movement'):
"""
Solve u' = -k**2*u, u(0)=I, u'(0)=0 by a finite difference
method with time steps dt, from t=0 to t=T.
"""
if dt > 2./k:
print 'Unstable scheme'
N = int(round(T/float(dt)))
u = zeros(N+1)
t = linspace(0, T, N+1)
umin = -1.2*I
umax = -umin
period = 2*pi/k # period of the oscillations
window_width =
plot_manager = MovingPlotWindow(
window_width, dt, yaxis=[umin, umax],
mode=mode)
u[0] = I
u[1] = u[0] - 0.5*dt**2*k**2*u[0]
for n in range(1,N):
u[n+1] = 2*u[n] - u[n-1] - dt**2*k**2*u[n]
if plot_manager.plot(n):
s = plot_manager.first_index_in_plot
plot(t[s:n+2], u[s:n+2], 'r-',
t[s:n+2], I*cos(k*t)[s:n+2], 'b-',
axis=plot_manager.axis(),
title="Solution of u'' + k^2 u = 0 for t=%6.3f (mode: %s)" % (t[n+1], mode))
plot_manager.update(n)
'''
def __init__(self, window_width, dt, yaxis=[-1,1],
mode='continuous movement',
pause=1.5):
"""
==================== ====================================
Argument Description
==================== ====================================
window_width tmax-tmin in a plot window
dt time step (constant)
yaxis extent of y axis
mode method for moving the plot window,
see below.
==================== ====================================
The mode parameter has three values:
* ``'continuous movement'``:
the plot window moves one time step for each plot.
* ``'continuous drawing'``: the curves are drawn from left
to right, one step at a time, and plot window jumps
when the curve reaches the end.
* ``'jumps'``: the curves are shown in a window for a time
equal to the pause argument, then the axis jumps
to a new time window of the same length
See also the test block of the module for
testing out the three different modes of this class.
"""
self.taxis_length_in_steps = int(round(window_width/float(dt)))
self.dt = dt
self.mode = mode
self.taxis_length = self.taxis_length_in_steps*self.dt
self.first_index_in_plot = 0
self.taxis_min = 0
self.yaxis = yaxis
self.pause = pause
self.n_prev = 0
def axis(self):
"""Return the axis limits as a list ``[xmin, xmax, ymin, ymax]``."""
return [self.taxis_min, self.taxis_min + self.taxis_length,
self.yaxis[0], self.yaxis[1]]
def plot(self, n):
"""
Return True if a plot is to be drawn at time step number ``n``,
otherwise return False.
"""
if self.mode == 'continuous movement':
return True
elif self.mode == 'continuous drawing':
# Update self.first_index_in_plot and self.taxis_min
# every self.taxis_length_in_steps time step
if n % self.taxis_length_in_steps == 0:
self.taxis_min += self.taxis_length
self.first_index_in_plot += self.taxis_length_in_steps
# Always plot the curves in continuous drawing
return True
else:
# Plot every self.taxis_length_in_steps time step only
if (n+1) % self.taxis_length_in_steps == 0:
return True
else:
return False
def update(self, n):
"""Update the plot manager (``MovingPlotWindow``) at time step ``n``."""
if self.mode == 'continuous movement':
if n > self.taxis_length_in_steps:
self.taxis_min += self.dt
self.first_index_in_plot += n - self.n_prev
self.n_prev = n
elif self.mode == 'jumps' and \
(n+1) % self.taxis_length_in_steps == 0:
# After plot is shown, sleep and then update plot
# window parameters
time.sleep(self.pause)
self.taxis_min += self.taxis_length
self.first_index_in_plot += self.taxis_length_in_steps
def _demo(I, k, dt, T, mode='continuous movement'):
"""
Solve u' = -k**2*u, u(0)=I, u'(0)=0 by a finite difference
method with time steps dt, from t=0 to t=T.
"""
if dt > 2./k:
print 'Unstable scheme'
N = int(round(T/float(dt)))
u = zeros(N+1)
t = linspace(0, T, N+1)
umin = -1.2*I
umax = -umin
period = 2*pi/k # period of the oscillations
plot_manager = MovingPlotWindow(8*period, dt, yaxis=[umin, umax],
mode=mode)
u[0] = I
u[1] = u[0] - 0.5*dt**2*k**2*u[0]
for n in range(1,N):
u[n+1] = 2*u[n] - u[n-1] - dt**2*k**2*u[n]
if plot_manager.plot(n):
s = plot_manager.first_index_in_plot
plot(t[s:n+2], u[s:n+2], 'r-',
t[s:n+2], I*cos(k*t)[s:n+2], 'b-',
axis=plot_manager.axis(),
title="Solution of u'' + k^2 u = 0 for t=%6.3f (mode: %s)" \
% (t[n+1], mode))
plot_manager.update(n)
if __name__ == '__main__':
from scitools.std import *
T = 40
_demo(1, pi, 0.1, T, mode='continuous movement')
time.sleep(10)
figure()
_demo(1, pi, 0.1, T, mode='continuous drawing')
time.sleep(10)
figure()
_demo(1, pi, 0.1, T, mode='jumps')
time.sleep(10)
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