Python Matplotlib.figure.Figure.dpi()用法及代码示例

# Implementation of matplotlib function  
import matplotlib.pyplot as plt 
import numpy as np 
   
  
fig = plt.figure() 
  
nx = int(fig.get_figwidth() * fig.dpi) 
ny = int(fig.get_figheight() * fig.dpi) 
  
data = np.random.random((ny, nx)) 
plt.plot(data) 
   
fig.suptitle('matplotlib.figure.Figure.dpi \ 
function Example', fontweight ="bold")  
  
plt.show()

# Implementation of matplotlib function   
import matplotlib.pyplot as plt 
from matplotlib import collections, colors, transforms 
import numpy as np 
   
nverts = 50
npts = 100
   
r = np.arange(nverts) 
theta = np.linspace(0, 2 * np.pi, nverts) 
  
xx = r * np.sin(theta) 
yy = r * np.cos(theta) 
  
spiral = np.column_stack([xx, yy]) 
   
rs = np.random.RandomState(19680801) 
   
xyo = rs.randn(npts, 2) 
   
colors = [colors.to_rgba(c) 
          for c in plt.rcParams['axes.prop_cycle'].by_key()['color']] 
   
fig, ax1 = plt.subplots() 
   
col = collections.RegularPolyCollection( 
    7, sizes = np.abs(xx) * 10.0, offsets = xyo,  
    transOffset = ax1.transData) 
  
trans = transforms.Affine2D().scale(fig.dpi / 72.0) 
  
col.set_transform(trans)  
ax1.add_collection(col, autolim = True) 
col.set_color(colors) 
  
fig.suptitle('matplotlib.figure.Figure.dpi() function\ 
 Example', fontweight ="bold")  
  
plt.show()