X N E C V I E W
---------------
A program for visualizing NEC2 input and output data (Unix/X-windows).

Copyright (C) 1998-2001, Pieter-Tjerk de Boer

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HISTORY:
--------

Version 0.1, 1998-06-06:
- first public release
- only few input card types supported

Version 0.2, 1998-12-13:
- almost all input card types supported
- added plotting of gain pattern
- colour added
- made front and back of surfaces distinguishable (by colour)

Version 0.3, 1999-1-15
- added PostScript output
- added third gain scale, "log"
- added buttons in the window
- added plotting of gain as slices in coordinate planes
- very small mouse dragging is treated as clicking
- corrected handling of output files which sweep over only one angle
- man page added, thanks to Joop Stakenborg, PA3ABA.

Version 0.4, 1999-5-30
- fixed bug in PostScript output
- added handling of GS cards
- "long" options now need -- instead of -
- fixed colours on 1bpp screen

Version 0.5, 1999-6-13
- added double buffering support: this reduces flickering by drawing in
  a separate 'Pixmap' instead of on the screen
- postscript now uses a private dictionary
- more general NEC output reading routine
- uses hinted motion events to speed up dragging
- motion+first button now rotates entire gain pattern, motion + second
  button rotates simplified gain pattern (quicker)
- fixed bug in linear gain scale
- removed -q/--quick option
- added a (too?) simple icon to appear when xnecview is iconified
The first 5 of these changes were essentially contributed by
Alan Bain, M1BXV; thanks!

Version 0.6, 1999-7-4
- added display of wire numbers
- added display of location of excitations and loads
- added display of 'X', 'Y' and 'Z' at axes
- configuration is now separate .h file
- corrected "ARRL style" gain scale (now 0.89 per 2 dB, as per the "ARRL
  Antenna Book"; tnx Don, VE3HUR)
- added handling of GM cards with non-zero ITS
- xnecview no longer exits when supplied with incorrect input
- an error message is printed when writing postscript fails (tnx Alan Bain)
- standard X command line options like -geometry now work

Version 1.0, 1999-7-25
- GW cards lacking the wire radius are now accepted
- GC cards now produce a warning
- added a bit of text to the postscript output
(tnx to Don VE3HUR for testing and remarks resulting in the above changes)
- iconifying now uses own icon again (didn't in 0.6)

Version 1.01, 2000-01-21
- card types of structure input ("GW" etc.) now also accepted in lower case

Version 1.02, 2000-03-25
- print not only maximum gain, but also direction of maximum gain and
  front-to-back-ratio.
- plot radial lines every 10 degrees when looking along the X/Y/Z axis
  (essentially contributed by Marco Menchise, IZ8AEB; tnx!)

Version 1.10, 2000-04-25
- added a window with plots of SWR, gain, etc. as a function of frequency
  (inspired by a preliminary implementation by Marco Menchise, IZ8AEB; tnx!)
- added support for radiation diagrams at multiple frequencies
- added plotting multiple sets of radiation data (= results from RP cards)
  for a frequency.
- added reading of multiple output files.
- removed unbuffered option.
- minor rewrites of some parts of the code.
- revised the documentation, creating new files USAGE and HISTORY, thus
  shortening README.

Version 1.11, 2000-07-15
- added "support" for GC cards (i.e., they are ignored since xnecview
  does not display the wire thickness).
- added calculation and plotting of gain and f/b in direction toward observer.
- added a line of text showing frequency and gain in bottom of 3D plot.
- added centered titles to the 2D plots.
- mostly rewrote the man page on the basis of the USAGE file.
- some optimizations by caching often calculated data; however, the Xserver's
  speed seems to be the limiting factor on my system, so this doesn't bring
  much.
- bugfix: clicking on the gainscale button if no radiation pattern data was
  available produced a segmentation fault.
- bugfix: reading multiple sets of radiation data sometimes gave an empty
  radiation pattern plot, depending on the order of the data.
- bugfix: GW cards with NRPT=0 or ITS>0 were not handled correctly.
Note: this version is a snapshot taken just before the GTK version started
to diverge too far to keep developing both versions in parallel.

Version 1.20, 2000-08-07
- user interface code converted to use the GTK library instead of Xaw/Xmu/Xt.
- added display of phase and magnitude of currents in wires (based on original
  suggestions by Marco Menchise IZ8AEB and Francesco Messineo IW8QPI; tnx!).
- changed mouse bindings for dragging and zooming
- added support for TL and NT cards
- dynamic memory allocation for radiation pattern data, resulting in much
  smaller memory usage.
- dropped the USAGE file, the man page is now the only file with detailed
  usage information.

Version 1.30, 2000-11-05
- added linear-in-voltage scale; the original linear scale was (and
  still is) linear in power.
- animated display of currents, charges, electric and magnetic (near) field
  vector, Poynting vector.
- command-line options; xnecview options in comment line of NEC input
- fix some compiler warnings
- limit display of Z to 20*Z0
- add display of phi(Z)/abs(Z)
- don't draw a square at each data point if there are many (window 2)
  (latter four changes essentially contributed by Joerg Wunsch DL8DTL; tnx!)
- number of grid lines in freqplots adapts to size of graph
- output files without currents information no longer cause a segfault
- some other minor fixes

Version 1.31, 2001-06-24
- changed axes of frequency plots: number of subdivisions can now be
  variable, resulting in a more readable axis (stepsizes are now always
  multiples of 1, 2, 2.5, or 5; no longer 4 or 7.5).
- if f/b is unknown, '-' is printed (instead of -1e-308) in table
- hide 'nan' on axes (window 2) if no relevant data available
- impedance (Z0) can now have up to 4 digits (instead of 2)
- new option: -aupdate to set the update interval of animation
- bugfix: extremely large values of Zi could hang xnecview
- some small fixes in choosing which frequency is used for radiation
  pattern display after reloading

