Name: DATFIL  4
The routine DATFIL opens a file for data input.
The call is:  ISTAT = DATFIL (CFIL)
CFIL          is  the  name  of the  data file.  The default
              extension is '.gdf' (Graphics Data File). 
ISTAT         is the returned status.  DATFIL returns -1  if
              it fails, or zero.
Name: DATCLS  4
The routine DATCLS closes the current data file.
The call is:  ISTAT = DATCLS ()
ISTAT         is the returned status.  DATCLS returns -1  if
              it fails, or zero.
Name: DATHDR  4
The routine  DATHDR  prints the header of a data file on the
screen.
The call is:  ISTAT = DATHDR ()
ISTAT         is the returned status of  DATHDR and can have
              the  values 0 and -1. On error, DATHDR returns
              -1.
Name: DATVAR  4
The routine  DATVAR  returns the value of a variable defined
in the header of a data file.
The call is:  V = DATVAR (CNAME)
CNAME         is the name of the variable.
Name: DATCNT  4
The routine DATCNT returns the number of data of the current
data block in a data file.
The call is:  N = DATCNT (COPT)
COPT          is a string with the values
 = 'ROWS'     means  the number of rows in the  current data
              block.
 = 'COLUMNS'  means  the number  of columns  in the  current
              data block.
 = 'FULL'     means  the number  of data in the current data
              block.
 = 'BLOCKS'   means the number of blocks in the data file.
Name: DATRAY  4
The routine  DATRAY  creates an array containing a column of
the current data block in a data file.
The call is:  XRAY = DATRAY (NCOLUMN)
NCOLUMN       defines the column of the data file.
XRAY          is a floating point array returned by DATRAY.
Name: DATMAT  4
The routine  DATMAT  creates an array  containing  the whole
current data block of the data file.
The call is:  XMAT = DATMAT ()
XMAT          is a  twodimensional  floating point array re-
              turned by DATMAT.
Name: DATBLK  4
The routine  DATBLK  sets the  current  data block of a data
file.
The call is:  ISTAT = DATBLK (NBLOCK)
NBLOCK        specifies the current data block.
ISTAT         is the  returned status.  DATBLK  returns 0 if
              the data block  NBLOCK  is defined,  and -1 if
              NBLOCK  is not  defined  in the  current  data
              file.
