


 Remove the bins indicated by the mask array
 Syntax:
   >> wout = mask (win, mask_array)
 Input:
 ------
   win                 Input sqw object
   mask_array          Array of 1 or 0 (or true or false) that indicate
                      which points to retain. 
                       Numeric or logical array of same number of elements
                      as the data.
                       Note: mask will be applied to the stored data array
                      according as the projection axes, not the display axes.
                      Thus permuting the display axes does not alter the
                      effect of masking the data.
 Output:
 -------
   wout                Output dataset.