;****************************************************************************
;+
;*NAME:
;
;    ATRD 
;
;*PURPOSE:
;
;    To convert FITS ASCII table entries to correct data types 
;
;*CALLING SEQUENCE:
;
;    ATRD,BYTE_EQ,TYPE,VARIABLE
;
;*PARAMETERS:
;
;    BYTE_EQ (REQ) (I) (1) (B) 
;        The byte equivalent vector of the data variable to be converted.
;        (BYTE_EQ must be a vector.)
;
;    TYPE (REQ) (I) (0) (S)
;        Data type of VARIABLE described as a single character. Allowed
;        data types are: integer 'I', floating point 'E' or 'F', double 
;        precision 'D', and string 'A'. 
;
;    VARIABLE (REQ) (O) (01) (BILFD)
;        Converted output vector.
;
;*SIDE EFFECTS:
;
;*SYSTEM VARIABLES USED:
;
;
;*SUBROUTINES CALLED:
;
;	PARCHECK
;
;*EXAMPLE:
;
;*RESTRICTIONS:
;
;*NOTES:
;
;       Data types are based on those allowed in the TFORM FITS keyword.
;       One element output vectors are converted to scalars.
;
;	tested with IDL Version 2.1.2 (sunos sparc)    08 Nov 91
;	tested with IDL Version 2.3.2 (vax vms)        19 Oct 92
;       tested with IDL Version 2.1.2 (ultrix mipsel)  08 Nov 91
;       tested with IDL Version 2.2.0 (ultrix vax)     08 Nov 91
;
;*MODIFICATION HISTORY:
;
;	Randy Thompson 2/8/91 (based on FITSCON)
;-
;****************************************************************************
 pro atrd,byte_eq,type,variable
;
 if n_params(0) eq 0 then begin
    print,'PRO ATRD,BYTE_EQ,TYPE,VARIABLE'
    retall
 endif  ; n_params(0)
 parcheck,n_params(0),3,'ATRD'
;
 tmpv = string(byte_eq)
 byte_elems = n_elements(tmpv)
 var_type = strupcase(type)
;
 case var_type of
    'I': begin                  ; integer
         variable = fix(tmpv)
         return
         endcase  ; I
    'E': begin         	 	; floating point
         variable = float(tmpv)
         return
         endcase  ; E
    'F': begin         		 ; floating point
         variable = float(tmpv)
         return
         endcase  ; F
    'D': begin    	         ; double precision
         variable = double(tmpv)
         return
         endcase  ; D
    'A': begin                   ; string
         variable = tmpv
         return
         endcase  ; A
   else: begin 			; unknown
         print,'Data type',var_type,' unknown, routine FITSCON'
         retall
         endelse
     endcase  ; var_type
 return
 end  ; atrd