compounding.py

import random
import matplotlib.pyplot as plt

var = 0.10

colors = ('#a6cee3', '#1f78b4', '#b2df8a', '#33a02c')

##for iColor, (tax1, tax2) in enumerate(((0.42, 0), (0.27, 0), (0, 0.42), (0, 0.27))):
for tax1, tax2 in ((0.42, 0),):

##    for rate in (0.08,):
    for iColor, rate in enumerate((0.04, 0.08, 0.12, 0.16)):

##        for iColor, years in enumerate((10, 20, 30, 40)):
        for years in (30,):

            x = []
            for i in range(100000):
                v0 = v = 100000
                for year in range(years):
                    v *= 1 + ((rate - var + 2 * var * random.random()) * (1 - tax1))
    ##                print(i, year, v)
                print(v, (v - v0), (v - v0) * (1 - tax2))
                v -= (v - v0) * tax2
                print(v)
    ##            print(tax1, tax2, rate, i, v)
                x.append(v)
            plt.hist(
                x, bins=100, alpha=.5,
                color = colors[iColor % 4],
                label='Tax {}%/{}%, Compounding {}%, Years {}'.format(
                    100*tax1, 100*tax2, 100*rate, years),
                )

plt.legend()

##plt.savefig('compounding_tax.png')
plt.savefig('compounding_rate.png')
##plt.savefig('compounding_years.png')