%
% 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 103
% 

close all; clc; clear all; 

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

y_truth = @(x) ( 50 * exp( - 5*x ) );

fprime = @(t,x) ( -5*x );
y0 = 50;

hs = [ 0.1, 0.2, 0.25, 0.4 ];
colors = [ 'r', 'b', 'g', 'c' ];
phs = [];
for hi=1:length(hs) 
  [tvals,yvals] = abm( fprime, [0,6], y0, hs(hi) );
  
  %relative_error = ( yvals - y_truth(tvals) ) ./ y_truth(tvals) ; 
  %plot( tvals, relative_error, ['-',colors(hi)] );
  
  ph = plot( tvals, yvals, ['-',colors(hi)] );
  phs = [hs, ph]; 
  hold('on');
end
grid('on');

legend( 'h 0.1', 'h 0.2', 'h 0.25', 'h 0.4', 'location', 'best' );

%saveas( gcf, '../../WriteUp/Graphics/Chapter5/c_5_p_9_plot.eps', 'epsc' );