import math

class SonarAltimeter:

def __init__(self):

self.pitch = 0.0

self.roll = 0.0

def set_attitude(self,attitude):

self.pitch, self.roll = attitude

self.pitch = math.radians(self.pitch)

self.roll = math.radians(self.roll)

def print_attitude(self):

print (math.degrees(self.pitch),math.degrees(self.roll))

def set_range(self,sonar_range):

self.range = sonar_range

def get_altitude(self):

return math.cos(self.pitch)*math.cos(self.roll)*self.range

if __name__ == "__main__":

import pylab

from numpy import *

altitude1 = []

altitude2 = []

a = SonarAltimeter()

a.set_range(10.0)

for angle in range(0,90):

a.set_attitude((angle,0.0))

#a.print_attitude()

altitude1.append(a.get_altitude())

a.set_range(11.0)

for angle in range(0,90):

a.set_attitude((angle,0.0))

#a.print_attitude()

altitude2.append(a.get_altitude())

alt = array(altitude1)

alt2 = array(altitude2)

diff = alt2 - alt

pylab.plot(alt,'b*-')

pylab.plot(alt2,'g*-')

pylab.plot(diff,'r-')

pylab.show()