Copyright  1992--2000 Shamim P Mohamed This file is part of the Plotfoil
package, which is freely redistributable under the terms of the Gnu Public
License Version 2.

This is the "plotfoil" package (V3.3) for modifying airfoils and printing
airfoil templates from data.  This is not shareware. You don't have to pay
me anything to use this program.  (But if you do send me money or gifts, I
won't complain!) You can give this to your friends -- in fact, I encourage
you to. However, it is not in the public domain; it is copyrighted. Read on
for a summary of terms of copying and redistribution. If you like this
program, please send me a nice picture postcard.

Plotfoil generates PostScript, does interpolation, spars, templates and
allowances for sheeting.  For more info on the formats supported and
options, see the comments in plotfoil.man.  The PostScript generated is
quite vanilla, and should print on any printer. Some printers may run out of
memory trying to print multi-page plots with lots of data. In this case you
have to find another printer or try removing some of the input data. (Using
ghostscript, this will probably manifest itself with a message like "Error:
/limitcheck in -filetype-" with /P on the stack.)

The PostScript is sent to standard output. Use redirection or a pipe to send
it to the printer.

This program runs on all the Unix-ish platforms I've tried, i.e. Sun3, Sun4
(SunOS4 and Solaris2), i486/Linux, SGI (personal Iris and 4D systems), NeXT,
Sequent Symmetry, VAX/BSD, DecStation/Ultrix. On the Macintosh it runs under
the CodeWarrior and ThinkC (6.0) environments. It also runs on MS-DOS (AT,
PS/2 50, 70, 80; MS C compiler, Turbo C++) and VMS (VAX, DEC4000). It has
worked on the following printers: Apple LaserWriters (Plus, II and NTX), NEC
LC890, LC890XL, HP LaserJet, QMS PS2000 and PS2200, NeWSprint/SPARCprinter,
DEC LN03 Scriptprinter, and ghostscript driving a whole bunch of other
printers -- the HP LaserJet and DeskJet series, Apple Imagewriter
etc. Ghostscript has no trouble and can drive numerous non-PS printers.

A graphical front-end program is available for Unix/X11 systems called
xplotfoil. It uses tcl/tk, which is freely available from a number of ftp
sites. (Read the comments in xplotfoil for a list.) Tk 4.x is required.
Tcl/tk is also available on MS-Windows platforms; check the standard archive
sites.

A MS-Windows graphical front-end is available for plotfoil; it should be at
the same site you found plotfoil. The canonical location is
ftp://ftp.drones.com/pfwin31.exe. Contact Michael Shellim
<mshell@cix.compulink.co.uk> for details.

In addition to plotfoil, two other programs are provided: mixfoils which
blends two sections, and editfoil which can modify the camber and/or
thickness of a section. These both read in sections in the same format as
plotfoil, and also produce data in the same format. The data can be piped
directly into plotfoil, or saved into a file.

There is also a program called naca which can generate the NACA 4-digit
sections and some of the 5-digit sections.

Please send any changes, additions, modifications etc. to me. This Program
is freely redistributable under the terms of the Gnu Public License. You may
give it away or even sell it, but you cannot restrict what your customers
may do with it - redistribute it, or even re-sell it. If you make a program
based on this one, or using code from this one, and redistribute it in any
way, the same conditions will apply to that program. If you do redistribute
this program (or any program derived from this one) in any way, you also
have to make the source code freely available, and all copyright notices
must remain intact.

The NACA airfoil data is in the public domain; the other data is covered by
the same License with the additional restriction that no extra charge beyond
that of copying media can be levied, and the UIUC Low-Speed Airfoil Test
program must be given credit and the MANIFESTO must be included.

For more details, see the file COPYING, which describes the Gnu Public
License.

******************************************************************************
*   									     *
* Plotfoil is dedicated to L. Peter Deutsch for writing ghostscript, Linus   * 
* Torvalds and the rest of the Linux team, and Richard Stallman for starting *
* the Free Software Foundation.                                              * 
* 									     *
******************************************************************************


			      *** Changes *** 
3.2 -> 3.3 8/96
 - added Tk front-end
 - support for different paper sizes
 - incorporated additional airfoil data (Lednicer) from the UIUC site
 - script lednicer.pl to convert Lednicer data into the Selig format
 - zero-divide bug fixed (5/98)
 - small change for egcs 1.1.2 (pgcc 2.91)

3.1 -> 3.2 9/95
 - added NACA code: naca.c, program naca
 - the NACA format (3 fields) is obsolete; converted everything
   to the 2 field format. The 3-field format will not be supported any
   more because it's too hard to keep in sync. A perl script nacafix.pl
   is provided to convert to the 2 field format.

3.0 -> 3.1 6/95
 - the -a option to turn sections
 - bug fixes:
   NACA format not handled; missing &yy in read_foil()
   plot() called with incorrect arguments from ui.c, breaking interactive
   mode fixed up some bogus prototypes

2.3 -> 3.0 12/94
 - rewrite and code reorganisation (for ANSI compliance)
 - the postscript is now Adobe DSC compliant, with EPSF for single page plots
 - interactive specification of parameters
 - fine-tuning the placement on the page
 - addition of airfoil modification programs:
      editfoil to change camber and thickness
      mixfoil to blend 2 airfoil sections
 - 2.3 bug fixes
 - addition of new airfoil data from Michael Selig's airfoil data WWW site

2.2 -> 2.3
 - cleaned up the postscript for sheeting - no line outside the airfoil
   outline any more
 - cleaned up spars - now they join up cleanly to the plot line
 - displaced image slightly to account for HP laserjets

2.1 -> 2.2
 - bug fix for too many points
 - fixed the multiple sheet thing to do sections deeper than 7" (In 2.1 the
   multiple thing would only do arbitrary chords, and clip the plot to one
   row of plots. In R/C applications this didn't matter since sections are
   rarely deeper than 7".)

2.0 -> 2.1
 - bug fix in units (re-done)
 - spar and template drawing

1.1 beta -> 2.0:
 - multiple page plots
 - improve interpolation
 - uniform options
 - units for options

On another topic, what do you think of the practice of granting patents on
software? Send me email.

===============================================================================
Shamim Mohamed shamim@drones.com

