PRO READ_COLUMNS, FILE_NAME, NUM_COL, NUM_ROW, CHOICE, X1, X2, X3, X4, X5, X6, $
                  X7, X8, X9
;
; READ_COLUMNS.PRO			Matthew DeLand			03/09/94
;
; This procedure is designed to get the contents of any column format ASCII file
;   and load each column into a vector.  If CHOICE = 0, all columns will be 
;   returned as variables.  If an array of values is specified for CHOICE, only 
;   those columns will be returned.
;
;   e.g. READ_COL, FILE, 10, 100, [2,4,6], X, Y, Z will return the contents of
;   columns 2, 4, & 6 in variables X, Y, Z, each of which will be FLTARR(100)
;
PROG_NAME = '/disk16/deland/idlcode/read_columns.pro'
;
; The data file is assumed to be in the current directory unless otherwise noted
;
OPENR, UNIT, FILE_NAME, /get_lun
;
DATA = FLTARR(NUM_COL, NUM_ROW)
READF, UNIT, DATA
;
; Extract all columns if CHOICE = 0
;
IF (n_elements(CHOICE) EQ 1) THEN BEGIN
   I = 1
   WHILE (I LE NUM_COL) DO BEGIN
      CASE I OF
         1:  X1 = transpose(DATA(0,*))
         2:  X2 = transpose(DATA(1,*))
         3:  X3 = transpose(DATA(2,*))
         4:  X4 = transpose(DATA(3,*))
         5:  X5 = transpose(DATA(4,*))
         6:  X6 = transpose(DATA(5,*))
         7:  X7 = transpose(DATA(6,*))
         8:  X8 = transpose(DATA(7,*))
         9:  X9 = transpose(DATA(8,*))
      ENDCASE
;
      I = I+1
   ENDWHILE
;
; If only specific columns desired, get those
;
ENDIF ELSE BEGIN
   N_CHOICE = n_elements(CHOICE)
   I = 1
   WHILE (I LE N_CHOICE) DO BEGIN
      CASE I OF
         1:  X1 = transpose(DATA(CHOICE(I-1)-1,*))
         2:  X2 = transpose(DATA(CHOICE(I-1)-1,*))
         3:  X3 = transpose(DATA(CHOICE(I-1)-1,*))
         4:  X4 = transpose(DATA(CHOICE(I-1)-1,*))
         5:  X5 = transpose(DATA(CHOICE(I-1)-1,*))
         6:  X6 = transpose(DATA(CHOICE(I-1)-1,*))
         7:  X7 = transpose(DATA(CHOICE(I-1)-1,*))
         8:  X8 = transpose(DATA(CHOICE(I-1)-1,*))
         9:  X9 = transpose(DATA(CHOICE(I-1)-1,*))
      ENDCASE
;
      I = I+1
   ENDWHILE
;
ENDELSE
;
; Close input file, then return all results
;
CLOSE, UNIT 
;
RETURN
;
END