In early 1600 Johannas Kepler conclude that all the planets in the solar system move in elliptical orbits with the sun at a focus, thus, the importance of ellipse in science. Ellipse is a Python program for students and tutors at higher levels of education . There are two equations of an ellipse : x^2/a^2 + y^2/b^2 and: x^2/b^2 + y^2/a^2 the foci are on the x axis or y axis. From Ellipse program the student will be able to sketch the ellipse, by drawing a box with (a) and (-a) units on the major axis and ( b) and (-b) units on the minor axis. Since Ellipse program determine the values of a and b and the position of the foci c. c = Square-Root (a^2 – b^2)
Python, 55 lines
Download
Copy to clipboard1 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 | #On the name of ALLAH
#Author : Fouad Teniou
#Date : 23/09/08
#Version 2.4
import math as m
Class Ellipse:
""" Class that represent an ellipse """
def __call__(self,**kargs): # ** allows to convert from keywords to dictionary
""" Python run __call__ method for function call expressions applied to instance """
self.kargs = kargs
self._a = "%2.1f"
self._b = chr(253)
self._c = self._a% m.sqrt(self.kargs.get('a'))
self._d = self._a% m.sqrt(self.kargs.get('b'))
self._e = self._a% m.sqrt(abs(self.kargs.get('a') - self.kargs.get('b'))
self._f = self._a% m.sqrt(abs(self.kargs.get('b') - self.kargs.get('a'))
#Determine if Ellipse equation should be displayed, based on keys’ values
if (len(kargs) == 2 and self.kargs.has_key('a') and self.kargs.get('a') != 0
and self.kargs.has_key('b') and self.kargs.get('b') !=0
and self.kargs.get('a') != self.kargs.get('b')):
if self.kargs.get('a') > self.kargs.get('b'):
self._e
else:
self._f
#raise ValueError if one or more of keys’ values are not appropriate
else:
raise ValueError, \
("\n<Ellipse equation should be of the form : \
\nx%s/a%s + y%s/b%s = 1 or x%s/b%s + y%s/a%s = 1 (a!=0 and b!=0) " % \
(self._b,self._b,self._b,self._b,self._b,self._b,self._b,self._b)
def __str__(self):
""" String representation of an ellipse """
if self.kargs.get('a') > self.kargs.get('b')
return "\n<Ellipse function x%s\%s + y%s\%s = 1: x%s has the larger dominator , the major axis is along the x -axis \
\n\n-- The coordinates of the foci are : (%s,0) and (-%s,0) \
\n\n-- Drawing a box extending a = %s on each side of the origin along the x-axis and extending \
\n b = %s on each side of the origin along the y-axis as a guide yield the graph" % \
(self._b,self.kargs.get('a'),self._b,self.kargs.get('b'),self._b,self._e,self._e,self._c,self._d)
else:
return "\n<Ellipse function x%s\%s + y%s\%s = 1: y%s has the larger dominator , the major axis is along the y- axis \
\n\n-- The coordinates of the foci are : (0, %s) and (0,-%s) \
\n\n-- Drawing a box extending a = %s on each side of the origin along the y-axis and extending \
\n b = %s on each side of the origin along the x-axis as a guide yield the graph" % \
(self._b,self.kargs.get('a'),self._b,self.kargs.get('b'),self._b,self._f,self._f,self._d,self._c)
if __name__ == "__main__":
test = Ellipse()
test(a=4,b=2)
print test
test(a=17,b=25)
print test
test(a=0, b= 5)
print test
|
Tags: algorithm, algorithms
