1from math import pi, sin, cos, hypot, sqrt 2 3# Math functions 4 5def degToRad(deg): 6 return (deg/180.0)*pi 7 8def radToDeg(rad): 9 return (rad/pi)*180.0 10 11def polarToRect(polar): 12 r = polar[0] 13 theta = polar[1] 14 return (r*cos(theta), r*sin(theta)) 15 16def bessel(z, t=0.00001): 17 j = 1 18 jn = 1 19 zz4 = z*z/4 20 for k in range(1, 100): 21 jn *= -1 * zz4 / (k*k) 22 j += jn 23 24 if jn < 0: 25 if jn > t: 26 break 27 else: 28 if jn < t: 29 break 30 return j 31