One method to extract QNFs from the simulation results is to use DV to produce an appropriate 1D slice of the data, then use xvs' reduce function to plot a given point as a function of time. In the following example, we assume that the real part of the Teukolsky function is called "phre".
  1. send phre to the DV (sdftodv phre)

  2. from the Functions window, clone phre with a filter to select the desired theta=constant slice of the data (we recommend slicing along theta=pi/2). For example, if the dimension of phre is 65x33 in (r,theta), then the following filter argument can be used (see HERE for help on using filters)
       ib = 1,65,17,17
    Enter phre_slice (say) as the new name for the register, and click Go!

  3. On the DV main window, select phre_slice, and then "Write selected SDF(s) to disk" from the file menu, and save it to the local drive.

  4. From a shell, send the slice to xvs (sdftoxvs phre_slice.sdf).

  5. Use xvs' reduce -> y[j] function to plot the desired point as a function of time.