Python+matplotlib绘制不同大小和颜色散点图实例

import numpy as npimport matplotlib.pyplot as pltimport matplotlib.cbook as cbook# Load a numpy record array from yahoo csv data with fields date, open, close,# volume, adj_close from the mpl-data/example directory. The record array# stores the date as an np.datetime64 with a day unit ('D') in the date column.with cbook.get_sample_data('goog.npz') as datafile:  price_data = np.load(datafile)['price_data'].view(np.recarray)price_data = price_data[-250:] # get the most recent 250 trading daysdelta1 = np.diff(price_data.adj_close) / price_data.adj_close[:-1]# Marker size in units of points^2volume = (15 * price_data.volume[:-2] / price_data.volume[0])**2close = 0.003 * price_data.close[:-2] / 0.003 * price_data.open[:-2]fig, ax = plt.subplots()ax.scatter(delta1[:-1], delta1[1:], c=close, s=volume, alpha=0.5)ax.set_xlabel(r'$/Delta_i$', fontsize=15)ax.set_ylabel(r'$/Delta_{i+1}$', fontsize=15)ax.set_title('Volume and percent change')ax.grid(True)fig.tight_layout()plt.show()