%
% Examples 9.15 and 9.17
% 
% epage 432
% 
% Written by:
% -- 
% John L. Weatherwax                2008-02-20
% 
% email: wax@alum.mit.edu
% 
% Please send comments and especially bug reports to the
% above email address.
% 
%-----

clear all; 
close all; 
clc; 

addpath('../../Code/CSTool');
load filip; 

[xs,inds] = sort(x);
ys        = y(inds); 

% plot the original data: 
fd=figure; 
ho = plot( x, y, 'k.' ); hold on; grid on; 
title( 'the filip data' ); 

line_styles={'-',':','--','-.'}; 
line_colors='cmkg'; 
data_plt_h = []; 
res_plt_h = []; 

fr=figure; hold on; 

poly_degs = [ 2,4,6,10 ]; 

for ii=1:length(poly_degs),
  deg = poly_degs(ii); 
  
  % assume we *know* the dimension of the polynomial to fit: 
  [pcoef,s] = polyfit(x,y,deg); 
  
  % evaluate this polynomial model:
  yp = polyval(pcoef,x); 
  
  % plot this polynomial model:
  figure(fd); 
  tph=plot( x, yp, ['-',line_colors(ii)] ); 
  data_plt_h(end+1) = tph; 
  
  % plot the residuals v.s. the fitted value yp: 
  res = y-yp; 
  figure(fr); 
  tph=plot( x, res, [line_colors(ii)] ); 
  xlabel( 'predictor x' ); ylabel( 'residual' ); 
  title( ['residual dependence plot for a polynomial model of degree', num2str(ii)] ); 
  %axis( [0 1 -2.5 2.5] );
  res_plt_h(end+1) = tph; 
  
  %pause; 
end

figure(fd); 
legend(data_plt_h, {'deg 2','deg 4','deg 6','deg 10'}, 'location', 'northwest' ); 
saveas( gcf, '../../WriteUp/Graphics/Chapter10/prob_10_5_data_w_models', 'epsc' ); 

figure(fr); 
legend(res_plt_h, {'deg 2','deg 4','deg 6','deg 10'}, 'location', 'northeast' ); 
saveas( gcf, '../../WriteUp/Graphics/Chapter10/prob_10_5_res_plts', 'epsc' ); 

clear functions;