sysgettype.m

similer program for matlab

## Copyright (C) 1998, 2000, 2002, 2003, 2004, 2005, 2007
##               Auburn University.  All rights reserved.
##
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## -*- texinfo -*-
## @deftypefn {Function File} {} sysgettype (@var{sys})
## return the initial system type of the system
##
## @strong{Input}
## @table @var
## @item sys
## System data structure.
## @end table
##
## @strong{Output}
## @table @var
## @item systype
## String indicating how the structure was initially
## constructed. Values: @code{"ss"}, @code{"zp"}, or @code{"tf"}.
## @end table
##
## @acronym{FIR} initialized systems return @code{systype="tf"}.
## @end deftypefn

function systype = sysgettype (sys)

  if (nargin != 1)
    print_usage ();
  endif

  if (! isstruct (sys))
    error ("sysgettype: input sys is not a structure");
  endif

  typestr = {"tf", "zp", "ss"};
  systype = typestr{sys.sys(1) + 1};

endfunction