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Diffstat (limited to 'modules/polynomials/macros/diophant.sci')
| -rwxr-xr-x | modules/polynomials/macros/diophant.sci | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/modules/polynomials/macros/diophant.sci b/modules/polynomials/macros/diophant.sci new file mode 100755 index 000000000..d052415bc --- /dev/null +++ b/modules/polynomials/macros/diophant.sci @@ -0,0 +1,30 @@ +// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab +// Copyright (C) ????-2008 - INRIA +// +// 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 [x,err]=diophant(p1p2,b) + //solves diophantine equation p1*x1+p2*x2=b + //with p1p2 a polynomial vector [p1 p2] + //b polynomial + //x polynomial vector [x1;x2] + //if the equation is uncompatible err=||p1*x1+p2*x2-b||/||b|| + //else err=0 + //! + p1=p1p2(1);p2=p1p2(2) + [x,u]=bezout(p1,p2) + p1=u(2,2);p2=u(1,2)// + if degree(x)==0 then + x=b*u(:,1) + err=0 + else + [r,q]=pdiv(b,x) + err=norm(coeff(b-x*q),2)/norm(coeff(b),2) + x=q*u(:,1) + end +endfunction |