title: Hatching frequency on plots
body: <p>Suppose I have the following script that produces a plot (as shown below) where some datapoints have hatching. At DPI = 200, the hatching frequency (space between dots) is good, but if I want to increase the resolution of the plot (DPI = 600 for example), the dots become very fine. Is there a way to set the gap between dots? Thanks in advance.</p>
  
  <pre><code>import numpy as np
  from matplotlib import pyplot as plt
  from mpl_toolkits.basemap import Basemap
  
  
  Sig = np.random.rand(50,50)
  Sig = np.ma.masked_greater(Sig, 0.25)
  
  f, ax1 = plt.subplots(1,1)
  
  ax1.pcolor(np.linspace(0,90,50),np.linspace(0,50,50),Sig, hatch=".",alpha=0)
  
  fig = plt.gcf()
  fig.set_size_inches(8, 8)
  fig.savefig('Trial.png',bbox_inches='tight', dpi=200)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/o7u5N.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o7u5N.png" alt="enter image description here"></a></p>