title: Removing elements from dictionaries while maintaining form
body: <p>I have a dictionary containing time intervals of multiple objects i.e. effectively a 2D array with time in the x axis and object in the y. I also have the same shape dictionary for stellar flux values to go with those times and finally I have a dictionary containing the Stellar ID's which is a 1D array of strings. </p>
  
  <p>Along with these is a dictionary with '<code>FLAG</code>' values where if <code>dic['FLAG'] != 0</code> then the corresponding flux and time values are to be discarded. </p>
  
  <p>Using <code>time_new = (dic['time'][np.where(dic['FLAG'] == 0.)])</code> seems to go through the 2D time dictionary appending each accepted value onto the the end of the next rather than simply removing those values which are unsuitable and cutting away at the overall 2D array form. </p>
  
  <p>Does anyone have any suggestions for how to tackle such a problem? Many thanks!</p>