% Script: TestInvProb1
% Description:  Contains test problem for use by TestInvSteady
% Try alpha = 1, bta = 1, d = pi/3 for this example.
% The alternate conformal to ln works, albeit not as well,
% and *without* economization.
% Forward problem is Example 5.1 of MS paper.

% Problem parameters
global G = 1; % flux rhs in BC.
global A = 1; % coefficient of c(0) in BC
global B = -0.5; % coefficient of c'(0) in BC
global edecay = 1; % exponential decay (0=false)

% DEFINE EXACT SOLUTION

function retval = csoln(x)
% usage: csoln(x)
% description: this computes the solution function csoln(x)

retval = exp(-(x/2)^2);

endfunction

%

function retval = csolnp(x)
% usage: csolnp(x)
% description: this computes the solution derivative csoln'(x)

retval = -0.5*x*exp(-(x/2)^2);

endfunction

%

function retval = csolnpp(x)
% usage: csolnpp(x)
% description: this computes the solution's second derivative csoln''(x)

retval = (-0.5+0.25*x^2)*exp(-(x/2)^2);

endfunction

% DEFINE THE COEFFICIENTS:

function retval = D(x)
% usage: D(x)
% description: this computes the fcn D(x)
% Reminder: If you change this, you must also change Dp

retval =  1 - exp(-2*x)/2;

endfunction

%

function retval = Dp(x)
% usage: Dp(x)
% description: this computes the fcn D'(x)

retval =  exp(-2*x);

endfunction

%

function retval = v(x)
% usage: v(x)
% description: this computes the fcn v(x)
% Reminder: If you change this, you must also change vp

retval = 1;

endfunction

%

function retval = vp(x)
% usage: vp(x)
% description: this computes the fcn v'(x)

retval = 0;

endfunction

%

function retval = lam(x)
% usage: lam(x)
% description: this computes the fcn lam(x)

retval = 1;

endfunction

%

function retval = f(x)
% usage: f(x)
% description: this computes the fcn f(x)

% computer generated by Maple
t4 = exp(-x*(8.0+x)/4);
t7 = x*x;
t8 = t7/4.0;
t9 = exp(-t8);
t13 = exp(-t8-2.0*x);
retval = x*t4/2+3.0/2.0*t9-t13/4-t7*t9/4+t7*t13/8-x*t9/2;

endfunction

% DEFINE THE WEIGHT FUNCTION

function retval = p(x)
% REMINDER:  p(0) must equal 1
% usage: p(x)
% description: this computes the weight fcn p(x)

% If you change this, you must also change pp(x)
%retval = exp(-x.^2);
retval = exp(-x);

endfunction

%

function retval = pp(x)
% usage: pp(x)
% description: this computes the bdy fcn p'(x)

%retval = -2*x*exp(-x^2);
retval = -exp(-x);

endfunction

%