function [time,expdays] = timeconvert(doy,hhmm,sec);

% [time,expdays] = timeconvert(doy,hhmm,sec);
%
% This function creates decimal time and expdays vectors from an array of data A
% where time is recorded in day-of-year, hour-minute, and potentially seconds.
% Example:  A(1,1:3) =   1   1210   05    corresponds to 12:10:05 on January 1. 
%           A(1,1:2) = 244    820         corresponds to 8:20 on August 31. 
%                    =  32   1530         corresponds to 3:30pm on February 1
%
% Usage:  having a time vector in decimal format allows you to easily plot 
% variables that are a function of time and which span several days.  
% 
% Inputs:
% doy = day of year vector = A(:,doy_col), where A is the data array and doy_col is
% the column number for the day of year data 
% hhmm = hour/minute vector = A(:,hhmm_col), where A is the data array and hhmm_col is
% the column number for the hour/minute data of form HHMM (i.e. 1:15pm = 1315)
% sec = seconds vector = A(:,sec_col).  
%
% NOTE:  size(hhmm) must equal size(doy) which much equal size(sec).  
%
% Outputs:
% time = row x 1 array containing the time of each row-record of A in
%	 decimal format, i.e. 12:00:00 on day 210 would be recorded as 210.5
% expdays = (# of experiment days in A) x 1 array
%	    each entry contains a different day of year
%
% If seconds are not recorded in A, then do this:
% 
% [time,expdays] = timeconvert(A(:,doy_col),A(:,hhmm_col),zeros(size(A(:,doy_col))))
%
% Written by Brian Hornbuckle, February 14, 2000.
% Modified by Brian Hornbuckle on October 3, 2000, June 5, 2001, March 30, 2011.

[rows] = length(hhmm);

% time = hours*(day/24 hours) + minutes*(day/(24*60minutes)) + seconds*(day/(24*60*60seconds))

h = floor(hhmm./100);		% hours
m = (hhmm./100 - h).*100;	% minutes

time = doy + h./24 + m./(24*60) + sec./(24*60*60);

%-------------- creating vector which contains experiment days

currentday = 0;			% initialize variables
n = 0;

for k = 1:rows
  day = doy(k);
  if day ~= currentday
    n = n+1;
    expdays(n) = day;
    currentday = day;
  end;
end;

expdays = expdays';		% change to row vector