% -- 
% Jeff Sevadjian
% Research Technician
% Monterey Bay Aquarium Research Institute
% 7700 Sandholdt Rd
% Moss Landing, CA 95039, USA
% ph: +1 831-775-1888

% Air temp from the 200WX is biased due to short power-on time.
%  Here, we compare air temp from the 200WX and the nearby MLML
%  weather station, and derive a relationship to correct 200WX air temp.

%define buoy, deployment, data directory
 buoy = 'oa2';
 dep = '201606';

 atlas = '//atlas.shore.mbari.org/';
 mydirOA = [atlas 'OA_Moorings/deployment_data/' ...
    buoy '/' dep '/realTime/'];

%read-in .csv files
 met = csvread([mydirOA 'MET.csv'],1,0);
 mlml = csvread([atlas 'OA_Moorings/cal_data/MET/MLML_2016-06.csv'],1,2);

%convert time in Unix to Matlab datenum
 dn = datenum([1970 1 1]);
 met(:,1) = dn + met(:,1)/86400/1000;
 mlml(:,1) = dn + mlml(:,1)/86400;
 clear dn;

%simple time-series plots
 figure; hold on;
 plot(mlml(:,1),mlml(:,6),'b.-');
 plot(met(:,1),met(:,3),'g.-');

%NaN empty MET data
 met(met(:,3)==0,3) = NaN;
 
%align
 for n=1:size(met,1)
   [m(n),i(n)] = min(abs(met(n) - mlml(:,1)));
 end
 f = find(m < 30/1440);
 x = met(f,3);
 y = mlml(i(f),6);
 clear n m i f;

%get rid of NaN values
 f = find(sum(isnan([x y]')) > 0);
 x(f) = [];
 y(f) = [];
 clear f;

%scatter plot
 figure; hold on;
 plot(x,y,'k.');

%get regression
 pf = polyfit(x,y,1); % y = 0.3401x + 9.4422

%check
 pv = polyval(pf,[min(x) max(x)]);
 plot([min(x) max(x)],pv,'b-');