d1mach.f

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c Copyright (C) 1996-2018 John W. Eaton
c
c This file is part of Octave.
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c Octave is free software: you can redistribute it and/or modify it
c under the terms of the GNU General Public License as published by
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c GNU General Public License for more details.
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c
      double precision function d1mach (i)
      integer i
      logical init
      double precision dmach(5)
      double precision dlamch
      external dlamch
      save init, dmach
      data init /.false./
      if (.not. init) then
        dmach(1) = dlamch('u')
        dmach(2) = dlamch('o')
        dmach(3) = dlamch('e')
        dmach(4) = dlamch('p')
        dmach(5) = log10(dlamch('b'))
        init = .true.
      endif
      if (i .lt. 1 .or. i .gt. 5) goto 999
      d1mach = dmach(i)
      return
  999 write (*, 1999) i
 1999 format (' d1mach - i out of bounds', i10)
      call xstopx (' ')
      d1mach = 0
      end