ARE Final Vr(x,y) shortened

# Ici on fait les imports, les règlages de la fenêtre, etc... mais on ne s'y intéressera pas.
#
def VR(X,Y):
    l = pi/2 - atan(Y/X)
    r = sqrt(X**2+(Y-Ro)**2)
    return Vo*(Ro/r - 1)*(sin(l))

Vo = 220000
Ro = 262282594 * 10**12

scale = W / Ro
#
min = -1
max = Vo
for x in range(1,W) :
    for y in range(1,H) :
        X,Y = x/scale, y/scale
        Vr = VR(X,Y)

        if Vr < min or min == -1:
            min = Vr
#
for x in range(1,W) :
    for y in range(1,H) :
        X,Y = x/scale, y/scale
        Vr = VR(X,Y)

        if Vr > max:
            coeff = 1
        else :
            coeff = (Vr-min)/(max-min)
        plot(x,y,rgb(coeff*255, 0, (1-coeff)*255))