integer*4 function isangl (degsam, ramang, isampl)
c
c-----------------------------------------------------------------------
c
c     Routine calculates the phase angle (isangl = deg) for a given
c     instrument sample for a maf1 data record, given a spin rate
c     (degsam = degs/sample) and an initial phase angle (ramang = deg),
c     normally returned from refang. Ramang is expected in range +/- 180
c     degrees. Returned isangl value is also in +/- 180 degree range.
c
c-----------------------------------------------------------------------
c
      integer*4 isampl
c
c-----------------------------------------------------------------------
c-----------------------------------------------------------------------
c
      ang = ramang + ((isampl-1) * degsam) + 720.0
      ang = amod(ang, 360.0)
      isangl = ang
      if (isangl .gt. 180) isangl = isangl - 360
c
c-----------------------------------------------------------------------
c-----------------------------------------------------------------------
c
      return
      end