%Class for CO907.
%__________________________________________
%Author: Jiarui Cao
%Date: 19 Nov 2013
%Purpose: Problem Sheet 2. Q2.6 Detrend data


close all;
clear all;
clc;
clf;


%% Load data
%set file path
%filepath =['/Users/jiaruicao/Dropbox/Teaching/TACO907/Sheet2/data/'];

%The code below are generated from 'import data'.
%filename1=[filepath 'ftse.dat'];
filename1=['ftse.dat'];
delimiter = '\t';
startRow = 2;
formatSpec = '%f%f%[^\n\r]';
fileID = fopen(filename1,'r');
dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false);
Day = dataArray{:, 1};
FTSE = dataArray{:, 2};
fclose(fileID);

filename2=['xray.dat'];
delimiter = ' ';
startRow = 6;
formatSpec = '%f%f%*s%*s%*s%*s%[^\n\r]';
fileID = fopen(filename2,'r');
dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'MultipleDelimsAsOne', true, 'EmptyValue' ,NaN,'HeaderLines' ,startRow-1, 'ReturnOnError', false);
fclose(fileID);
t_xray = dataArray{:, 1};
xray = dataArray{:, 2};

filename3=['temperatureanomaly.dat'];
Temp=load(filename3);
Month =1:1:length(Temp);


%% Plot the raw data. 

hold on
% plot(Day,FTSE,'om');
% xlabel('day');
% ylabel('FTSE');
%figure()
%plot(t_xray,xray,'or');
% xlabel('time');
% ylabel('x-ray');
% figure()
plot(Month,Temp,'xr');
xlabel('month');
ylabel('temp');


% % detrend FTSE
% M=3; % here we use order 3 polynomials.
% p = polyfit(Day,FTSE,M);
% yfit = polyval(p,Day);
% plot(Day,yfit,'k','linewidth',2.0);
% Y = FTSE-yfit;
% plot(Day,Y);
% 
% lg=legend('Original','k','Derended');
% ptitle=['M=' num2str(M)];
% title(ptitle,'fontsize',20);
% set(lg,'fontsize',24,'location','northwest');
% 
% % output data
% savefilename = ['ftse_detrended.dat'];
% dlmwrite(savefilename, [Day,Y], 'delimiter', '\t', 'precision', 6);
% detrend temprature
Month=Month.';
M=3; % still use order 3 polynomials
p =polyfit(Month,Temp,M);
TempFit = polyval(p,Month);
plot(Month,TempFit,'k','linewidth',2.0);
YTemp = Temp-TempFit;
plot(Month,YTemp,'ob');

lg=legend('Original','fit','Derended');
ptitle=['M=' num2str(M)];
title(ptitle,'fontsize',20);
set(lg,'fontsize',24,'location','northwest');
% output data
savefilename = ['temperatureanomaly_detrended.dat'];
dlmwrite(savefilename, YTemp, 'delimiter', '\t', 'precision', 6);

% %% detrend xray
% % 
% % truncate the original data. Not necessay.
% t_xray=t_xray(1:4400);
% xray=xray(1:4400);
% 
% % Generate equally spaced data
% tstep=(max(t_xray)-min(t_xray))/(length(xray)-1); %compute step size
% tq = min(t_xray):tstep:max(t_xray); %generate new time array
% 
% % interp1 is used for interpolating data equally spaced.  
% %vq1 = interp1(t_xray,xray,tq,'spline'); %Cubic spline interpolation
% vq1 = interp1(t_xray,xray,tq,'pchip');%Piecewise cubic Hermite interpolation
% 
% plot(t_xray,xray,'o',tq,vq1,'s');
% lg=legend('Original','interp1');
% set(lg,'fontsize',24,'location','northwest');
% 
% 
% % detrend data as before
% M=3;
% p =polyfit(tq,vq1,M)
% TempFit = polyval(p,tq);
% plot(tq,vq1,'k','linewidth',2.0);
% Y = vq1-TempFit;
% plot(tq,Y,'xr');
% 
% 
% lg=legend('Original','terp1','fit','Derended');
% ptitle=['M=' num2str(M)];
% title(ptitle,'fontsize',20);
% set(lg,'fontsize',24,'location','northwest');
% % output data
% tq=tq.';
% Y=Y.';
% %savefilename = [filepath 'xray_detrended.dat'];
% savefilename = ['xray_detrended.dat'];
% dlmwrite(savefilename, [tq,Y], 'delimiter', '\t', 'precision', 6);