title: Matplotlib colorbar ticks format when using scientific notation
body: <p>I'm bothering you with a silly question, but I couldn't find an awnser. I'm trying to add a colorbar to an image using matplotlib. The issue comes when I try to format the ticks of the colorbar. I would like to have a scientific notation format, but at the same time control the number of decimals in the ticks. For example, with this code:</p>
  
  <pre><code>#format the colorbar ticks labels
  sfmt=ticker.ScalarFormatter(useMathText=True) 
  sfmt.set_powerlimits((0, 0))
  
  cb1=fig1.colorbar(imp,
                cax=axcbar,
                orientation="vertical",
                ticks=np.linspace(1.03*np.min(imest),0.97*np.max(imest),4),
                format=sfmt)
  cb1.set_label(r'$kg/s.m^2$')
  </code></pre>
  
  <p>I create this figure:</p>
  
  <p><a href="https://i.stack.imgur.com/llEWu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/llEWu.png" alt="enter image description here"></a></p>
  
  <p>I would like to have in the ticks only one decimal (i.e. 5.210 --> 5.2). Is this possible in a simple way? I've tried a lot of things without success.</p>
  
  <p>Thanks in advance.</p>