%
% Written by:
% --
% John L. Weatherwax                2009-04-21
%
% email: wax@alum.mit.edu
%
% Please send comments and especially bug reports to the
% above email address.
%
%-----

% EPage 136

addpath('../../BookCode');

close all; clc; clear 

xs = 0:0.25:3;
ys = [ 6.3806, 7.1338, 9.1662, 11.5545, 15.6414, 22.7371, 32.0696, 47.0756, 73.1596, 111.4684, 175.9895, 278.5550, 446.4441 ];
plot( xs, ys, '.k', 'MarkerSize', 18 ); hold('on'); grid('on');

% Fit the exponential model using fgenfit: 
%
c = fgenfit( 'c_7_p_6_fn_i', xs, ys );
ys_fn_i = c(1) + c(2) * exp( xs ) + c(3) * exp( 2 * xs );
plot( xs, ys_fn_i, '-k' ); 

% Fit the reciprical model using fgenfit: 
%
c = fgenfit( 'c_7_p_6_fn_ii', xs, ys );
ys_fn_ii = c(1) + c(2)./(1+xs) + c(3)./((1+xs).^2);
plot( xs, ys_fn_ii, '-r' ); 

% Fit a third degree polynomial to this data: 
%
poly_coefs = polyfit( xs, ys, 3 );
ys_poly = polyval( poly_coefs, xs );
plot( xs, ys_poly, '-b' );

legend( 'data', 'exponential model', 'reciprical model', 'cubic', 'location', 'best' );

%saveas( gcf, '../../WriteUp/Graphics/Chapter7/c_7_p_6_plot.eps', 'epsc' );