title: How to change numpy array based on mask array?
body: <p>I have an array data_set, size:(172800,3) and mask array, size (172800) consists of 1's and 0's. I would like to replace value form data_set array based on values (0 or 1) in mask array by the value defined by me: ex : [0,0,0] or [128,16,128].</p>
  
  <p>I have tried, "np.placed" function but here the problem is the incorrect size of mask array. </p>
  
  <p>I have also checked the more pythonic way:
  data_set[mask]= [0,0,0] it worked fine but for some raison only for 2 first elements.</p>
  
  <pre><code>data_set[mask]= [0,0,0]
  
  data_set = np.place(data_set, mask, [0,0,0])
  </code></pre>
  
  <p>My expected output is to change the value of element in data_set matrix to [0,0,0] if the mask value is 1. </p>
  
  <p>ex.</p>
  
  <pre><code>data_set = [[134,123,90] , [234,45,65] , [32,233,45]]
  mask = [ 1, 0, 1]
  
  output = [[0,0,0] , [234, 45,65] , [0,0,0]]
  </code></pre>