Python Matplotlib.axes.Axes.set_transform()用法及代码示例

# Implementation of matplotlib function 
import numpy as np 
import matplotlib.pyplot as plt 
import matplotlib.transforms as mtransforms 
  
delta = 0.25
x = y = np.arange(-3.0, 3.0, delta) 
X, Y = np.meshgrid(x, y) 
Z1 = np.exp(-X**2 - Y**2) 
Z2 = np.exp(-(X - 1)**2 - (Y - 1)**2) 
Z = (Z1 - Z2) 
  
transform = mtransforms.Affine2D().rotate_deg(30) 
fig, ax = plt.subplots() 
      
im = ax.imshow(Z, interpolation ='none', 
               origin ='lower', 
               extent =[-2, 4, -3, 2],  
               clip_on = True) 
  
trans_data = transform + ax.transData 
im.set_transform(trans_data) 
  
x1, x2, y1, y2 = im.get_extent() 
ax.plot([x1, x2, x2, x1, x1],  
        [y1, y1, y2, y2, y1], 
        "ro-", 
        transform = trans_data) 
  
ax.set_xlim(-5, 5) 
ax.set_ylim(-4, 4) 
  
fig.suptitle('matplotlib.axes.Axes.set_transform() \ 
function Example\n\n', 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.axes.Axes.set_transform() function\ 
 Example\n', fontweight ="bold") 
  
fig.canvas.draw() 
  
plt.show()