#!/usr/bin/python
"""Example of util.shift_scale_y()
"""
# pylint: disable=I0011, C0103, E1101, R0801
import numpy as np
from modelicares import util
from modelicares.texunit import number_label
# Generate some random data.
x = range(100)
y = np.cumsum(np.random.random(100) - 0.5)
y -= y.min()
y *= 1e-3
y += 1e3 # Small magnitude and large offset
ylabel = number_label('Velocity', 'mm/s')
# Plot the data.
ax = util.setup_subplots(2, 2, label='examples/shift_scale_y')[0]
for a in ax:
a.plot(x, y)
a.set_ylabel(ylabel)
# Shift and scale the axes.
ax[0].set_title('Original plot')
ax[1].set_title('After applying offset and factor')
util.shift_scale_y(ax[1])
#!/usr/bin/python
"""Example of util.shift_scale_x()
"""
# pylint: disable=I0011, C0103, E1101
import numpy as np
from modelicares import util
from modelicares.texunit import number_label
# Generate some random data.
x = np.linspace(55478, 55486, 100) # Small range and large offset
xlabel = number_label('Time', 's')
y = np.cumsum(np.random.random(100) - 0.5)
# Plot the data.
ax = util.setup_subplots(2, 2)[0]
for a in ax:
a.plot(x, y)
a.set_xlabel(xlabel)
# Shift and scale the axes.
ax[0].set_title('Original plot')
ax[1].set_title('After applying offset and factor')
util.shift_scale_x(ax[1])
def bode_plot(mag,
phase,
f,
in_Hz=True,
in_dB=True,
in_deg=True,
label=None,
axes=None,
*args,
**kwargs):
r"""Create a Bode plot for a system.
**Arguments:**
- *sys*: Linear input/output system (Lti)
- *freqs*: List or frequencies or tuple of (min, max) frequencies over which
to plot the system response.
If *freqs* is *None*, then an appropriate range will be determined
automatically.
- *in_Hz*: If *True*, the frequencies (*freqs*) are in Hz and should be
plotted in Hz (otherwise, rad/s)
- *in_dB*: If *True*, plot the magnitude in dB
- *in_deg*: If *True*, plot the phase in degrees (otherwise, radians)
- *label*: Label for the legend, if added
- *axes*: Tuple (pair) of axes to plot into
If *None* or (*None*, None*), then axes are created
- *\*args*, *\*\*kwargs*: Additional options to matplotlib (color,
linestyle, etc.)
**Returns:**
1. Axes of the magnitude and phase plots (tuple (pair) of matplotlib axes)
**Example:**
.. plot::
:include-source:
>>> from control.matlab import ss
>>> sys = ss("1. -2; 3. -4", "5.; 7", "6. 8", "9.")
>>> axes = bode_plot(sys)
"""
phase = unwrap(phase)
freq_unit = Hz if in_Hz else rad / s
# Create axes if necessary.
if axes is None or (None, None):
axes = (plt.subplot(211), plt.subplot(212))
# Magnitude plot
axes[0].semilogx(f / freq_unit,
to_dB(mag) if in_dB else mag,
label=label,
*args,
**kwargs)
# Add a grid and labels.
axes[0].grid(True)
axes[0].grid(True, which='minor')
axes[0].set_ylabel("Magnitude in dB" if in_dB else "Magnitude")
# Phase plot
axes[1].semilogx(f / freq_unit,
phase / (deg if in_deg else rad),
label=label,
*args,
**kwargs)
# Add a grid and labels.
axes[1].grid(True)
axes[1].grid(True, which='minor')
axes[1].set_xlabel(number_label("Frequency", "Hz" if in_Hz else "rad/s"))
axes[1].set_ylabel(number_label("Phase", "deg" if in_deg else "rad"))
return axes
