v13.37:  cvs is the official release method.
v13.36:  still in progress of switching
v13.30:  switch to cvs.
v12.29:  Bug in hydra_fv control button fixed.  Bug introduced when
    hydra_fpitch was made re-enterant.  hydra_fv: one may now select
    standard contour plots or colorplots as well as filled contour
    plots via the control button.

v12.30:

v12.31:  moments, currents, bfield all use hydra_ytick_parm.  This code
    selects the yaxis range, number of ticks and tick positions.

v12.32:  kp, kp_extra use hydra_ytick_parm.

v12.33: hydra_events looks for a date-dependent filename now.

v12.34: papco 9 moves the switch vector from the style widget to
    the programmer's will, and by doing so any panel that uses the style
    widget crashes.  All such panels sense which version of papco is 
    running and handles this condition properly.

v12.35: hydra_other_panel wasn't checked in.

v12.36: hydra_spec_slice changes.

v12.37: hydra_ytick_parm sets the yscl vector ylog for overplots.

v12.38: slice hydra_faverage added, which for the meantime is the
    same as the standard papco slice.


v12.39: simple spec interfaced.

v12.40: misnamed draw_hydra_tpphr.pro "draw_hydra_ttphr.pro".

v12.41: introduction of hydra_message, a widget_message-like facility
    with added functionality.  (It doesn't halt production waiting for
    response.)

v12.42: anisotropy plots don't require both up and down measurements,
    instead one or the other is okay.


v12.43: hydra_status button, under miscellany

v12.44: prettied up hydra_status

v12.45: survey filename can be explicitly specified in hydra_spec.
     Also, added more control over level one reads in hydra_spec.

v12.46: forgot to check in a file associated with v12.45

v12.47: hydra_payload_to_gsm and _to_gse vectorized

v12.48: nothing new, I wasn't sure if I had released it yet.

v12.49: hydra_faverage on-line.  It is an enhanced version of the old
   spectrum slice, that allows printing and more control.

v12.50: hydra_faverage plots omni,aligned,opposed,perp simultaneously.
   Also plots verses velocity.

v12.51: fixed a few bugs in faverage.

v12.52: input structure changes to hydra_fpitch require changes in hydra_fv
   panel.

v12.53: Removed data filter from r_hydra_moments, added it to
p_hydra_moments, and made the filter an option in hydra_moments_panel.

v12.54: added moments slicer, which displays the moments exit codes for
 the block.

v12.55: hydra_fv draws axis if it's the bottom panel.

v12.56: explicit file specification in moments panel.

v12.57: Added eflux_parl and eflux_over_b to moments, total_eflux_parl to current...PPQ

v12.58: don't poly above ref etc if it's an overplot.

v12.59: ooops

v12.60: charge and mass defined in r_moments, also if file name is specified.

v12.61: P9 convert_seconds_to_time now returns Y2K date.  This is detected
   and handled in hydra_fv.  Certainly other codes will be affected by this
   as well!

v12.62: continued work in Y2K problems.

v12.63: hydra_fv widget works properly under IDL5.1

v12.64: y2k problems caused by convert_t90_to_date repaired.

v12.65: hydra_fv reads old lists!

v12.66: hydra_plot polyfills handle NaN's.

v12.67: faverage slicer prints in color properly.

v12.68: added additional parameters to kp panel.

v12.69: added density_hot and mean_energy_hot to kp panel.

v12.70: Fixed cdf variable read in r_hydra_kp, labels in p_hydra_kp.

v12.71: introduced papco_interactive, which is a reliable test of the
    mode papco's in.  Also fixed a minor Y2K bug in p_hydra_spec and 
    p_hydra_skew.

v12.72: papco_interactive properly introduced.

v12.73: whoops

v12.74: events files can have titles in them.  

v12.75: events files can have annotations in them, which are printed
  in the background.

v12.76: fixed cs_hydra_current Inf problem for utot_parl.

v12.79: oops

v12.80: Y2K bug fixed in hydra_spec_slice_user_hydra_fpitch (or whatever it's
    called.)

v12.81: cs_hydra_current now looks for a save save for the ancillary
	bfield quantities needed.  If it doesn't exist, business as
	usual.  This makes the Moments-J panel much faster.

v12.82: Fixed nsamp=1 problem in cs_hydra_current.pro

v12.83: walen slicer hookup.

v12.84: First version of the walen slicer routines...Time
	for Jack to beta test it...

v12.86: Walen is ready for testing again...

v12.87: Makin' things pretty...

v12.88: "configure" button removed from moments and currents module.

v12.89: bfield panel shifted measurements by 1/2 of the aliasing interval.
   Bug considered minor since bfield time resolution is much higher
   than other data sets it might be compared with.

v12.90: moments panel doesn't hang when realized.

v12.91: faverage slicer prints message if pitch angle-filtered spectrograms
   are not available.  

v12.92: bug in bfield units found and fixed.  Low res bfield might report 
  units were counts when they were really nT.

v12.94: Changed the data access in hydra_events..Now from Walen CDF file.

v12.95: moments panel doesn't hang when realized -- I think I forgot to check
   it in last time.

v12.96: moments plots have hydra id next to them when in presentation mode.

v12.97: whoops.

v12.98: q_parl_over_b color highlighted.
v12.99: new statistical method HR angyrotropy changes "index real" flag.
v13.00: HR angyro changes.
v13.01: rcfilter for moments.
v13.02: rc filter added for current.  
v13.03: cleaned up hydra_fv panel.
v13.04: fixed cyclotron frequency transciption error.  Was bmag*22, 
   is now bmag*28.
v13.05: fixed bug in kp panel that prevented multiple days from being read.
v13.06: fixed fix v13.05 that caused new problem.
v13.07: Trivial label change for pressure.
v13.08: minor fixes to miscellany:hydra_instrument_status
v13.09: hydra_plotcolor performed poorly with p_hydra_ppa, now fixed.
v13.10: rc_index filter passes between 0.1 and 10.0
v13.11: moments: skip down only 2 lines for right side label.  mean energy
        is labelled "kT" in presentation mode, hyd_ident doesn't
        print anything in presentation mode.
v13.12: current module no longer prints "presentation units."
v13.13: hydra_ticks only prints date once (per day).
v13.14: PPA module is brought up to snuff; Can now handle all of the
        different energy sequences brought on by the 19971203 snafu...
v13.15: Uperp magnitude labels changed in moments module.
v13.16: bfield panel plots theta and phi in degrees.  Label changes too.
v13.17: Moments-J panel and quantities get major overhaul
	Labels fixed, J is independent of ion density now, filtering
	Jparl and Jperp is done differently now, the panel itself
	has a reworked plotting/filtering options interface.
v13.18: bfield panel has switch for lag_correction.
v13.19: 2D slices (hydra_spec_slice and faverage) print four-digit dates.
v13.20: ilt sign assignment to be same as mag_latitude now performed
	in r_hydra_other.pro and nowhere else.
v13.21: Fixed up presentation labels for kp and moments panels.
v13.22: panel editors: added the yoffset and xoffset keywords for P9.
v13.23: hydra_fv P9 compatibility problems resolved.
v13.24: bug in user_hydra_faverage slice fixed.
v13.25: hydra_moments_panel improvements
v13.26: De-commisioned the TPPION (KP_EXTRA), SPPION and TPPHR options
        Added TPP and SPP options to be used instead.
v13.27: Hooked up the SPP code...
v13.28: hydra_fv_control_event had a mistake that caused problems with newer
   rev's of IDL.
v13.29: p_hydra_spec handles case where mode(*) eq 0.
v13.30: case/endif bug is fixed in IDL5.3, so now it's fixed in hydra module.

v13.31: hydra_events reads file again.  Special code to overplot walen
  events disabled.
v13.32: r_hydra_moments uses b_used to switch over to the hk bfield.
v13.33: r_hydra_spec_sv uses hyd_cdf_varget, which handles endian problems.
v13.34: default events underplot is 
    /opt/hydra/tmp_data/other_data_sets/19960529_walen_events.txt
v13.35: added include_detectors switch in level1 spectrogram reads.
v13.36: added normalized z-axis (or AGC--automatic gain control) to 
   spectrogram panel.
v13.37: normalized z-axis uses density for normalization.
v13.40: invalid density-->invalid z value
v13.42: unify public and in-house versions of the module.  
   polar_hydra_public() controls which version to use.
v13.43: r_hydra_kp uses hyd_cdf_varget
v13.44: swwitch used now.  This takes care of the incompatibility with
   IDL 5.3 and up.  Many sites have been using modified versions of the
   hydra module, and I'm finally making the change official here.
v13.45: swwitch usage has been removed.  switch was introduced early on as
   work-around for an assumption in papco.  It is no longer required by papco,
   and removeing its use entirely should make the module compatible with 
   new versions of papco.
