www.pudn.com > matlab±à³Ì.zip > doy.m, change:1999-03-08,size:1807b

%  Script file: doy.m 
% 
%  Purpose:  
%    This program calculates the day of year corresponding  
%    to a specified date.  It illustrates the use switch 
%    and for constructs.  
% 
%  Record of revisions: 
%      Date       Programmer          Description of change 
%      ====       ==========          ===================== 
%    12/07/98    S. J. Chapman        Original code  
% 
% Define variables: 
%   day          -- Day (dd) 
%   day_of_year  -- Day of year 
%   ii           -- Loop index 
%   leap_day     -- Extra day for leap year 
%   month        -- Month (mm) 
%   year         -- Year (yyyy) 
 
% Get day, month, and year to convert 
disp('This program calculates the day of year given the '); 
disp('current date.'); 
month = input('Enter current month (1-12): '); 
day   = input('Enter current day(1-31):    '); 
year  = input('Enter current year(yyyy):   '); 
 
% Check for leap year, and add extra day if necessary 
if mod(year,400) == 0  
   leap_day = 1;          % Years divisible by 400 are leap years 
elseif mod(year,100) == 0  
   leap_day = 0;          % Other centuries are not leap years 
elseif mod(year,4) == 0 
   leap_day = 1;          % Otherwise every 4th year is a leap year 
else 
   leap_day = 0;          % Other years are not leap years 
end 
 
% Calculate day of year by adding current day to the 
% days in previous months. 
day_of_year = day; 
for ii = 1:month-1 
 
   % Add days in months from January to last month 
   switch (ii) 
   case {1,3,5,7,8,10,12}, 
      day_of_year = day_of_year + 31; 
   case {4,6,9,11}, 
      day_of_year = day_of_year + 30; 
   case 2, 
      day_of_year = day_of_year + 28 + leap_day; 
   end 
 
end 
 
% Tell user 
fprintf('The date %2d/%2d/%4d is day of year %d.\n', ... 
         month, day, year, day_of_year);