;+ 
; NAME: JULIAN 
;        
; PURPOSE: 
;     This procedure is used to sort dark image files. From a list 
;     of dark image file names, it will return only those file  
;     names that have not already been through this procedure. 
; 
; CATEGORY: 
;        
; CALLING SEQUENCE: 
;     JULIAN,FILES,NEWFILES,TIME 
; 
; INPUTS: 
;     FILES: A STRING ARRAY of names of dark images 
; 
;     TIME: A two byte integer, used to specify the images with 
;           the exposure time of interest. If no time is  
;           specified, then by default 60 will be chosen. 
;        
; KEYWORD PARAMETERS: 
;     None. 
; 
; OUTPUTS: 
;     NEWFILES: A STRING ARRAY of names of dark images that have not 
;              been run through this procedure. 
;      
;     TWO FILES  
;              
;       c:\idl\data\dark\julian0.drk : This file contains the dates 
;       and times, in Julian Seconds, at which the dark images, from 
;       camera 0, were aquired. 
; 
;       c:\idl\data\dark\julian1.drk : This file contains the dates 
;       and times, in Julian Seconds, at which the dark images, 
;       from camera 1, were aquired. 
; 
; COMMON BLOCKS: 
;     None. 
;        
; SIDE EFFECTS: 
;     None. 
; 
; RESTRICTIONS: 
;     All files must come from the same path.      
; 
; PROCEDURE:     
;     The first file name in the STRING ARRAY, files, is checked. 
;     If the path is of the form c:\images\dark\cam0(1)\ , then  
;     the procedure will look for files with filenames of the form,   
;     ???...TIME???. If no time is specified then by default TIME=60.    
;     If the files are of the form, c:\images\dark\cam0(1)\???...time.???    
;     then they are files created from dark exposure of the CCD. From  
;     these files the year,month,day and seconds in to the day at which 
;     the dark files was aquired is taken. Using a procedure called     
;     'ymds2js(year,month,day,second)' the date and time at which the  
;     dark file was aquired is changed into Julian Seconds. This provides    
;     a convinient number to associate with the darkfiles. These numbers    
;     are stored in a file named, c:\idl\data\dark\julian0(1).drk.  
;     Each time the procedure is run it check all the Julian Seconds  
;     from the new files, assuming they are of the right type, against  
;     the one stored in the in the file julian0(1).drk.Only the files  
;     that have dates in Julian Seconds, which are not in the file  
;     julian0(1).drk will have their filenames returned in the STRING  
;     of names NEWFILES .See also documentation for JS_STATS.  
; 
; MODIFICATION HISTORY: 
;     Written May 1994, by T A Oliynyk   
;- 
 
PRO julian,files,newfiles,time 
    
in=expose(files,time)              
              
camnum=STRMID(files(0),18,1)              
              
CASE camnum OF              
              
'0':BEGIN              
infiles=FINDFILE('c:\idl\data\dark\julian0.drk',count=count0)              
IF count0 NE 1 THEN BEGIN              
              
  OPENW,unit,'C:\idl\data\dark\julian0.drk',/GET_LUN              
  initial=ASSOC(unit,DBLARR(1))              
  initial(0)=[0]              
  CLOSE,unit              
  FREE_LUN,unit              
              
ENDIF              
              
OPENR,unit,'C:\idl\data\dark\julian0.drk',/GET_LUN                
filestat=FSTAT(unit)              
number=filestat.size/8              
julsec=DBLARR(number)              
READU,unit,julsec              
CLOSE,unit        
FREE_LUN,unit        
        
newfiles=['']              
              
FOR i=0, N_ELEMENTS(in)-1 DO BEGIN              
              
  rdkihd,in(i),header 
  Kih=gethd(header)              
  year=Kih.misc.dt.year              
  month=FIX(Kih.misc.dt.month)              
  day=FIX(Kih.misc.dt.day)              
  second=FIX(Kih.misc.tm.hour)*3600. + FIX(Kih.misc.tm.minute)*60. +$              
  FIX(kih.misc.tm.second)              
  js=ymds2js(year,month,day,second)              
  dummy=WHERE(Julsec EQ js,label)              
          
        
  IF label EQ 0 THEN BEGIN              
                
    julsec=[julsec,js]              
    newfiles=[newfiles,in(i)]              
       
  ENDIF              
ENDFOR              
          
IF N_elements(newfiles) GT 2 THEN BEGIN       
       
newfiles=newfiles(1:*)              
OPENW,unit,'C:\idl\data\dark\julian0.drk',/GET_LUN        
WRITEU,unit,julsec              
CLOSE,unit        
FREE_LUN,unit        
              
ENDIF ELSE BEGIN       
       
OPENW,unit,'C:\idl\data\dark\julian0.drk',/GET_LUN        
WRITEU,unit,julsec              
CLOSE,unit        
FREE_LUN,unit        
       
ENDELSE        
       
END              
              
'1':BEGIN              
infiles=FINDFILE('c:\idl\data\dark\julian1.drk',count=count1)              
              
IF count1 NE 1 THEN BEGIN              
  OPENW,unit,'C:\idl\data\dark\julian1.drk',/GET_LUN              
  initial=ASSOC(unit,DBLARR(1))              
  initial(0)=[0]              
  CLOSE,unit              
  FREE_LUN,unit              
              
ENDIF              
              
OPENR,unit,'C:\idl\data\dark\julian1.drk',/GET_LUN                
filestat=FSTAT(unit)              
number=filestat.size/8              
julsec=DBLARR(number)              
READU,unit,julsec              
CLOSE,unit        
FREE_LUN,unit        
              
newfiles=['']              
         
FOR i=0, N_ELEMENTS(in)-1 DO BEGIN              
              
  rdkihd,in(i),header 
  Kih=gethd(header)              
  year=Kih.misc.dt.year              
  month=FIX(Kih.misc.dt.month)              
  day=FIX(Kih.misc.dt.day)              
  second=FIX(Kih.misc.tm.hour)*3600. + FIX(Kih.misc.tm.minute)*60. +$              
  FIX(kih.misc.tm.second)              
  js=ymds2js(year,month,day,second)              
  dummy=WHERE(Julsec EQ js,label)              
                
  IF label EQ 0 THEN BEGIN              
                  
    julsec=[julsec,js]              
    newfiles=[newfiles,in(i)]              
                  
                
  ENDIF              
ENDFOR              
              
IF N_elements(newfiles) GE 2 THEN BEGIN       
       
 newfiles=newfiles(1:*)              
 OPENW,unit,'C:\idl\data\dark\julian1.drk',/GET_LUN        
 WRITEU,unit,julsec              
 CLOSE,unit        
 FREE_LUN,unit        
              
ENDIF ELSE BEGIN       
       
 OPENW,unit,'C:\idl\data\dark\julian1.drk',/GET_LUN        
 WRITEU,unit,julsec              
 CLOSE,unit        
 FREE_LUN,unit        
       
ENDELSE       
              
END              
              
ELSE:BEGIN             
             
 MESSAGE, 'None of the files are from camera 0 or 1.',$              
         /INFORMATIONAL              

 Newfiles=['']
                            
END             
              
ENDCASE              
              
END