Function:     INSIDEPTR

Purpose:      Indicates whether inside or outside subframe defined by
              INITPTR.

File:         initptr.c

Author:       K.G. Begeman

Use:          LOGICAL INSIDEPTR( IP,    Output   INTEGER
                                 NP )   Output   INTEGER

              INSIDEPTR  Returns .TRUE. when still some data inside
                         subframe in readbuffer, else .FALSE.
              IP         If INSIDEPTR .eq. .TRUE., offset pointer from
                         start of readbuffer to where first data value
                         insiderame can be found.
              NP         If INSIDEPTR .eq. .TRUE., number of data values
                         inside subframe in readbuffer starting at IP.

Notes:        When INSIDEPTR returns .FALSE. it reinitializes itself
              to the state just after the call to INITPTR. So it can
              be used again to do a different operation on data inside
              the sub frame.

Related Docs: initptr.dc2, outsideptr.dc2

Updates:      Nov 15, 1988: KGB, Creation date.
              Feb 27, 1990: KGB, Reinitialization implemented.