dates_old.m

Geodetic tools to be used in navigation analysis

% DATES
% Converts between the following date formats:
%  - Year, Month, Day
%  - Year, Day-of-Year
%  - Decimal Year
%
% Required M-files: caldate, juldate

% Created 24 May 96, M. Craymer
% Modified 03 Aug 96, Converted to MATLAB
% Modified 29 Sep 98, Convert each option to all other formats
% Modified 25 Mar 99, Converted to use isempty
% Modified 23 Apr 99, Corrected to use day 1 for beginning of year in juldate

clear;
ver = 'MATLAB 99.04.23';

disp(' ');
disp('DATES: Converts between different date formats.');
disp(['       M.Craymer, ' ver]);
disp(' ');

ok = 1;
while (ok)
  disp('Conversion from:');
  disp('  1) Year,Month,Day');
  disp('  2) Year,Day-of-Year');
  disp('  3) Decimal Year');
  iopt=input('Select conversion [0=quit] > ');

  if isempty(iopt)
    iopt = 0;
  end %if

  if (iopt == 0)
    ok = 0;
    disp(' ');

  elseif (iopt == 1)
    %fprintf(1,'\nEnter Year,Month,Day > ');       %Octave
    %[yr mn dy] = fscanf(0,'%f %f %f');            %Octave
    rec = input('Enter Year,Month,Day > ','s');    %MATLAB
    cdate = sscanf(rec,'%f %f %f');                %MATLAB
    yr = cdate(1);                                 %MATLAB
    mn = cdate(2);                                 %MATLAB
    dy = cdate(3);                                 %MATLAB
    jd=juldate(yr,mn,dy);
    doy = jd - juldate(yr,1,1) + 1;
    fprintf(1,'Year,Day-of-Year = %d %5.1\n',yr,doy);
    fprintf(1,'Decimal Year = %7.4f\n',yr+(doy-1)/365.25);
    fprintf(1,'Julian Date = %9.1f\n\n',jd);

  elseif (iopt == 2)
    %fprintf(1,'\nEnter Year,Day-of-Year > ');     %Octave
    %[yr doy] = fscanf(0,'%f %f');                 %Octave
    rec = input('Enter Year,Day-of-Year > ','s');  %MATLAB
    cdate = sscanf(rec,'%f %f');                   %MATLAB
    yr = cdate(1);                                 %MATLAB
    doy = cdate(2);                                %MATLAB
    jd = juldate(yr,1,1) + doy - 1;
    [yr mn dy] = caldate(jd);
    fprintf(1,'Year,Month,Day = %d %d %5.2f\n',yr,mn,dy);
    fprintf(1,'Year,Day-of-Year = %7.4f\n',yr+doy/365.25);
    fprintf(1,'Julian Date = %9.1f\n\n',jd);

  elseif (iopt == 3)
    %fprintf(1,'\nEnter Year & Decimal Year> ');   %Octave
    %yr = fscanf(0,'%f');                          %Octave
    yr = input('Enter Year & Decimal Year > ');    %MATLAB
    doy = (yr-floor(yr))*365.25;
    yr = floor(yr);
    jd = juldate(yr,1,1) + doy;
    [yr mn dy] = caldate(jd);
    fprintf(1,'Year,Month,Day = %d %d %5.2f\n',yr,mn,dy);
    fprintf(1,'Year,Day-of-Year = %d %6.2f\n\n',yr,doy);

  else
    fprintf(1,'*** Undefined transformation selected\a\n');
  end %if
end %while