Python script for calculating sail and find size for windsurf

windsurf_calc.py

#!/usr/bin/env python3
# ripoff of https://github.com/RoryMearns/Windsurf_Calculator/blob/master/javascript/windcalc.js

weight_kg = 70
sail_alpha = 1.34
fin_alpha = 4.9383
fin_extra = 3.0988


def get_sail(wind):
    weight_factor = sail_alpha * weight_kg
    sail_size = weight_factor / wind
    return sail_size


def get_fin(wind):
    fin_factor = sail_alpha * weight_kg
    fin_size = int(fin_alpha * fin_factor / wind + fin_extra)
    return fin_size


print(f'Freerider weight: {weight_kg} kg')
for wind in [10, 12, 13, 14, 15, 20, 25]:
    sail_size = get_sail(wind)
    fin_size = get_fin(wind)
    print(f'For {wind} knots, {sail_size:.1f} m2 sail, {fin_size} cm fin')