title: Delete points in scatter plot
body: <p>I plotted a scatter plot using python by importing data from text files and I want to delete points with x axis values 0. This is the program I have written</p>
  
  <pre><code>mat0 = genfromtxt("herbig0.txt");
  mat1 = genfromtxt("coup1.txt");
  pyplot.xlim([-2,6])
  pyplot.ylim([26,33])
  colors=['red', 'blue','green']
  pyplot.scatter(mat0[:,13], mat0[:,4], label = "herbig stars", color=colors[0]);
  if mat1[:,2] != 0:
  pyplot.scatter(mat1[:,2], mat1[:,9], label = "COUP data of SpT F5-M6 ", color=colors[1]);
  pyplot.scatter(mat1[:,2], mat1[:,10], label = "COUP data of SpT B0-F5", color=colors[2]);
  pyplot.legend();
  pyplot.xlabel('Log(Lbol) (sol units)')
  pyplot.ylabel('Log(Lx) (erg/s)')
  pyplot.title('Lx vs Lbol')
  pyplot.show();
  </code></pre>
  
  <p>This is my output <a href="https://i.stack.imgur.com/JPEAe.png" rel="nofollow noreferrer">graph</a> when I don't use the if statements.
  I want to delete all the blue points which have an x axis value of zero. Please suggest changes. If I use the if statement and all the points vanished.</p>
  
  <p><a href="https://i.stack.imgur.com/JPEAe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/JPEAe.png" alt="enter image description here"></a></p>