import math

def polars_1 (x, y):
#   angle en l'interval [0, 2PI]
#   funcio atan
    r = math.sqrt (x**2 + y **2)
    if x > 0 and y >=0:
        a = math.atan (y/x)
    elif x > 0 and y < 0:
        a = math.atan (y/x) + 2 * math.pi
    elif x <0:
        a = math.atan (y/x) + math.pi
    elif abs(x)  < 0.0001 and y > 0:
        a = math.pi/2
    elif abs(x) < 0.0001 and y < 0:
        a = 3 * math.pi / 2
#    a = math.degrees(a)
    return r,a

def polars_2 (x, y):
#   funcio atan2: dona l'angle en l'interval [-PI, PI]
    r = math.sqrt (x**2 + y **2)
    if abs (x) >= 0.0001:
        a = math.atan2 (y, x)
    else:
        if y > 0:
            a = math.pi/2
        else:
            a = -math.pi / 2
#    a = math.degrees(a)
    return r,a

# polars = polars_1
polars = polars_2

def calcula (radi):
    ag = 0.0
    while ag < 360:
        ar = math.radians(ag)
        x = radi * math.cos(ar)
        y = radi * math.sin(ar)
        r, ac = polars (x,y)
        print (ag, x, y, r, ac)
        ag = ag + 15
    return