oscilloscope.py

Below is the syntax highlighted version of oscilloscope.py from §1.5 Input and Output.

#-----------------------------------------------------------------------
# oscilloscope.py
#-----------------------------------------------------------------------

# Simulate the output of an oscilloscope. Assume that the vertical and
# horizontal inputs are sinusoidal. Use these equations:

#    x = A sin (wX + phiX)
#    y = B sin (wY + phiY)

import stddraw
import sys
import math

stddraw.setXscale(-1, +1)
stddraw.setYscale(-1, +1)
stddraw.setPenRadius(0.01)

A    = float(sys.argv[1])    # amplitudes
B    = float(sys.argv[2])
wX   = float(sys.argv[3])    # angular frequencies
wY   = float(sys.argv[4])
phiX = float(sys.argv[5])    # phase factors
phiY = float(sys.argv[6])

# Convert from degrees to radians.
phiY = math.radians(phiX)
phiY = math.radians(phiY)

t = 0.0
while True:
    x = A * math.sin(wX * t + phiX)
    y = B * math.sin(wY * t + phiY)
    stddraw.point(x, y)
    stddraw.show(10.0)
    t += 0.01
    #t += 0.0001

#-----------------------------------------------------------------------

# python oscilloscope.py 1 1 2 3 20 45

# python oscilloscope.py 1 1 5 3 30 45