Add docstrings for all of the defined functions.

Author: dihm

labscript/functions.py

@@ -15,40 +15,160 @@
 import numpy as np
 
 def print_time(t, description):
+    """Print time with a descriptive string.
+
+    Useful debug tool to print time at a specific point
+    in the shot, during shot compilation. Helpful when
+    the time is calculated.
+
+    Args:
+        t (float): Time to print
+        description (str): Descriptive label to print with it
+    """
     print('t = {0:.9f} s:'.format(t),description)
 
 def ramp(duration, initial, final):
+    """Defines a linear ramp.
+
+    f(t) = (final - initial)*t/duration + initial
+
+    Args:
+        duration (float): Duration of ramp
+        initial (float): Starting value of ramp
+        final (float): Ending value of ramp
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     m = (final - initial)/duration
     return lambda t: m*t + initial
 
 def sine(duration, amplitude, angfreq, phase, dc_offset):
+    """Defines a sine wave.
+
+    f(t) = amplitude*sin(angfreq*t + phase) + dc_offset
+
+    Args:
+        duration (float): Not used.
+        amplitude (float): Amplitude of sine wave.
+        angfreq (float): Angular frequency of sine wave.
+        phase (float): Phase of sine wave.
+        dc_offset (float): Verticle offset of sine wave.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     return lambda t: amplitude*sin(angfreq*(t) + phase) + dc_offset
 
 def sine_ramp(duration, initial, final):
+    """Defines a square sinusoidally increasing ramp.
+
+    f(t) = (final-initial)*(sin(pi*t/(2*duration)))^2 + initial
+
+    Args:
+        duration (float): Length of time for the ramp to complete.
+        initial (float): Initial value of ramp.
+        final (float): Final value of ramp.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     return lambda t: (final-initial)*(sin(pi*(t)/(2*duration)))**2 + initial
 
 def sine4_ramp(duration, initial, final):
+    """Defines a quartic sinusoidally increasing ramp.
+
+    f(t) = (final-initial)*(sin(pi*t/(2*duration)))^4 + initial
+
+    Args:
+        duration (float): Length of time for the ramp to complete.
+        initial (float): Initial value of ramp.
+        final (float): Final value of ramp.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     return lambda t: (final-initial)*(sin(pi*(t)/(2*duration)))**4 + initial
 
 def sine4_reverse_ramp(duration, initial, final):
+    """Defines a quartic sinusoidally decreasing ramp.
+
+    f(t) = (final-initial)*(sin(pi/2+pi*t/(2*duration)))^4 + initial
+
+    Args:
+        duration (float): Length of time for the ramp to complete.
+        initial (float): Initial value of ramp.
+        final (float): Final value of ramp.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     return lambda t: (final-initial)*(sin(pi/2+pi*(t)/(2*duration)))**4 + initial
 
 def exp_ramp(duration,initial,final,zero):
+    """Defines an exponential ramp via offset value.
+
+    f(t) = (initial-zero)*e^(-rate*t) + zero
+    rate = log((initial-zero)/(final-zero))/duration
+
+    Args:
+        duration (float): Length of time for the ramp to complete
+        initial (float): Initial value of ramp.
+        final (float): Final value of ramp.
+        zero (float): Zero offset of ramp.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     rate = 1/duration * log((initial-zero)/(final-zero))
     return lambda t: (initial-zero)*exp(-rate*(t)) + zero
 
 def exp_ramp_t(duration,initial,final,time_constant):
+    """Defines an exponential ramp via time constant.
+
+    f(t) = (initial-zero)*e^(-t/time_constant) + zero
+    zero = (final-initial*e^(-duration/time_constant))/(1-e^(-duration/time_constant))
+
+    Args:
+        duration (float): Length of time for the ramp to complete
+        initial (float): Initial value of ramp.
+        final (float): Final value of ramp.
+        zero (float): Zero offset of ramp.
+
+    Returns:
+        func: Function that takes a single parameter `t`.
+    """
     zero = (final-initial*exp(-duration/time_constant)) / (1-exp(-duration/time_constant))
     return lambda t: (initial-zero)*exp(-(t)/time_constant) + zero
 
 def piecewise_accel(duration,initial,final):
+    """Defines a piecewise acceleration.
+
+    Args:
+        duration (float): Length of time for the acceleration to complete.
+        initial (float): Initial value.
+        final (float): Final value.
+    """
     a = (final-initial)
     return lambda t: initial + a * (
     (9./2 * t**3/duration**3) * (t<duration/3)
     + (-9*t**3/duration**3 + 27./2*t**2/duration**2 - 9./2*t/duration + 1./2) * (t<2*duration/3)*(t>=duration/3)
     + (9./2*t**3/duration**3 - 27./2 * t**2/duration**2 + 27./2*t/duration - 7./2) * (t>= 2*duration/3))
 
 def pulse_sequence(pulse_sequence,period):
+    """Returns a function that interpolates a pulse sequence.
+
+    Relies on :obj:`numpy.digitize` to perform the interpolation.
+
+    Args:
+        pulse_sequence (:obj:`numpy:numpy.ndarray`): 2-D timeseries of
+            change times and associated states.
+        period (float): Period of each pulse.
+
+    Returns:
+        func: Interpolating function that takes a single parameter `t`.
+        Only well defined if `t` falls within the `pulse_sequence` change times.
+    """
     pulse_sequence = np.asarray(sorted(pulse_sequence, key=lambda x: x[0], reverse=True))
     pulse_sequence_times = pulse_sequence[:, 0]
     pulse_sequence_states = pulse_sequence[:, 1]