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我想要获得Matplotlib和Numpy的一些牵引力，但它不是很容易。Matplotlib和Numpy Math
我在做一个小项目开始处理Matplotlib和numpy的，但我被困...
下面是代码：
# Modules
import datetime
import numpy as np
import matplotlib.finance as finance
import matplotlib.mlab as mlab
import matplotlib.pyplot as plot
# Define quote
startdate = datetime.date(2010,10,1)
today = enddate = datetime.date.today()
ticker = 'uso'
# Catch CSV
fh = finance.fetch_historical_yahoo(ticker, startdate, enddate)
# From CSV to REACARRAY
r = mlab.csv2rec(fh); fh.close()
# Order by Desc
r.sort()
### Methods Begin
def moving_average(x, n, type='simple'):
"""
compute an n period moving average.
type is 'simple' | 'exponential'
"""
x = np.asarray(x)
if type=='simple':
weights = np.ones(n)
else:
weights = np.exp(np.linspace(-1., 0., n))
weights /= weights.sum()
a = np.convolve(x, weights, mode='full')[:len(x)]
a[:n] = a[n]
return a
### Methods End
prices = r.adj_close
dates = r.date
ma20 = moving_average(prices, 20, type='simple')
ma50 = moving_average(prices, 50, type='simple')
# Get when ma20 crosses ma50
equal = np.round(ma20,1)==np.round(ma50,1)
dates_cross = (dates[equal])
prices_cross = (prices[equal])
# Get when ma20 > ma50
ma20_greater_than_ma50 = np.round(ma20,1) > np.round(ma50,1)
dates_ma20_greater_than_ma50 = (dates[ma20_greater_than_ma50])
prices_ma20_greater_than_ma50 = (prices[ma20_greater_than_ma50])
print dates_ma20_greater_than_ma50
print prices_ma20_greater_than_ma50
现在我需要做这样的事情：
store the price of the "price_cross"
see if one day after the "ma20_greater_than_ma50" statment is true, if true store the price as "price of the one day after"
now do "next price_cross" - "price of the one day after" (price2 - price1) for all occurences
我该怎么做这个数学和更重要的。我如何获得Matplotlib和Numpy的牵引力。我应该买什么书？
给我一些线索。
最好的问候，