// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA - 1988 - C. Bunks
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution.  The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
function an=remezb(nc,fg,ds,wt)
    //an=remezb(nc,fg,ds,wt)
    //Minimax approximation of a frequency domain
    //magnitude response.  The approximation takes
    //the form
    //
    //          h = sum[a(n)cos(wn)]
    //
    //for n=0,1,...,nc.  An FIR, linear-phase filter
    //can be obtained from the output of the macro
    //by using the following Scilab commands
    //
    //          hn(1:nc-1)=an(nc:-1:2)/2;
    //          hn(nc)=an(1);
    //          hn(nc+1:2*nc-1)=an(2:nc)/2;
    //
    //  nc :Number of cosine functions
    //  fg :Grid of frequency points in [0,.5)
    //  ds :Desired magnitude on grid fg
    //  wt :Weighting function on error on grid fg
    //  an :Cosine filter coefficients
    //!


    //get frequency grid size

    ngrid=max(size(fg));

    //check for errors in input

    if min(fg)<0|max(fg)>0.5 then
        error(msprintf(gettext("%s: Wrong value for input argument #%d: Must be in the interval [%s, %s].\n"),"remezb",2,"0","0.5"));
    end,
    dsize=max(size(ds));
    wsize=max(size(wt));
    if dsize<>ngrid then
        error(msprintf(gettext("%s: Incompatible input arguments #%d and #%d: Same sizes expected.\n"),"remezb",2,3));
    end,
    if wsize<>ngrid then
        error(msprintf(gettext("%s: Incompatible input arguments #%d and #%d: Same sizes expected.\n"),"remezb",2,4));
    end,

    //set up the initial guess for the extremal frequencies

    iext=round(1:ngrid/nc:ngrid);
    iext(nc+1)=ngrid;
    iext(nc+2)=ngrid;

    //call remez.f

    an=remez(iext,ds,fg,wt);
    an=an(1:nc)
endfunction