In [[an earlier post|Hooke-update]], I reported seeing `surface
distance (m) (m)` columns in my playlist files, but had been unable to
reproduce them.  Today, after [fixing bugs with Curve
copying](http://www.physics.drexel.edu/~wking/code/hg/hgwebdir.cgi/hooke/rev/59390d466f0d),
I did reproduce them with:

    $ ./bin/hk.py
        -c 'load_playlist test/data/vclamp_picoforce/playlist'
        -c 'start_command_capture'
        -c 'zero_surface_contact_point --block approach'
        -c 'zero_surface_contact_point --block retract'
        -c 'stop_command_capture'
        -c 'apply_command_stack_to_playlist --enable-evaluate'
        -c 'flat_filter_playlist --block retract --min_points 1'
    Success
    ...
    Failure
    Expected a list of Peaks, not <class 'hooke.command.Failure'>:
      surface distance (m) not in retract (['z piezo (m)', 'deflection (m)',
      'surface distance (m) (m)', 'surface deflection (m) (m)']):
      list.index(x): x not in list

It appears to be a problem with curve reloading, since it doesn't come
up when I use a playlist with less than 100 (`Playlist._max_loaded`)
curves.

I'll update this post once I've tracked down the culprit.

[[!tag tags/hooke]]
[[!tag tags/programming]]