#! /usr/bin/octave -q

#      Copyright (c) 2000 Bruce Ravel
#      Permission is granted to copy, distribute and/or modify this
#      document under the terms of the GNU Free Documentation License,
#      Version 1.0 or any later version published by the Free Software
#      Foundation; with the Invariant Sections being "EXAFS Analysis
#      Using FEFF and FEFFIT, Part 1: Presentation", "EXAFS Analysis
#      Using FEFF and FEFFIT, Part 2: Commentary", and all related
#      analysis examples, with no Front-Cover Texts, and with no
#      Back-Cover Texts.  A copy of the license is included in the
#      section entitled "GNU Free Documentation License".


## This file (and all files associated with `EXAFS Analysis Using FEFF
## and FEFFIT') are free documentation; you can redistribute it and/or
## modify it under the terms of the GNU Free Documentation License as
## published by the Free Software Foundation; either version 1, or (at
## your option) any later version.

## You should have received a copy of the GNU Free Documentation License
## along with `EXAFS Analysis Using FEFF and FEFFIT'; see the file
## COPYING.  If not, write to the Free Software Foundation, 675
## Massachusettes Ave, Cambridge, MA 02139, USA.

## Permission is granted to make and distribute verbatim copies of this
## manual provided the copyright notice and this permission notice are
## preserved on all copies.

## Permission is granted to copy and distribute modified versions of this
## manual under the conditions for verbatim copying, provided that the
## entire resulting derived work is distributed under the terms of a
## permission notice identical to this one.

## Permission is granted to copy and distribute translations of this
## manual into another language, under the above conditions for modified
## versions, except that this permission notice may be stated in a
## translation approved by the author.

global halfpath = 3.9317;
global angled = 10;

function y = y (answer)
  global angled halfpath
  angle = angled*pi/180;
  y(1) = atan2(answer(2),answer(1)) - angle;
  y(2) = (1 + 1/cos(angle)) * answer(1) - halfpath;
endfunction

start=[halfpath; .3]
[answer, info] = fsolve ("y", start)
Tix = 2*answer(1)