Working with DuPont identity

In finance, we could find useful information from a firm's financial statements such as annual income statement, balance sheet, and cash flow statement. Ratio analysis is one of the commonly used tools to compare the performance among different firms and for the same firm over the years. DuPont identity is one of them. DuPont identity divides Return on Equity (ROE) into three ratios: Gross Profit Margin, Assets Turnover, and Equity Multiplier:

The following code will show those three ratios with different colors. Here we have the following information about some firms:

Ticker	Fiscal Year Ending Date	ROE	Gross Profit Margin	Assets Turnover	Equity Multiplier
IBM	December 31, 2012	0.8804	0.1589	0.8766	6.3209
DELL	February 1, 2013	0.2221	0.0417	1.1977	4.4513
WMT	January 31, 2013	0.2227	0.0362	2.3099	2.6604

The Python code is as follows:

import numpy as np
import matplotlib.pyplot as plt
ind = np.arange(3)
plt.title("DuPont Identity")
plt.xlabel...