/*
 * The Spar Library - modular math parser
 * Copyright (C) 2000,2001 Davide Angelocola <davide178@inwind.it>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 *
 */

#ifndef _sl_poly_
#define _sl_poly_

#include <spar/sl_vector.h>

struct poly_s
{
  sl_vector *c;
  sl_vector *g;
  double grade;
};

typedef struct poly_s sl_poly;

__BEGIN_DECLS
/* 
 * Evaluate polynomial
 * c[0] + c[1] x + c[2] x^2 + ... + c[len-1] x^(len-1)
 */
double sl_poly_eval (const double c[], const int len, const double x);

/* Solve for real or complex roots of the standard quadratic equation,
 * returning the number of real roots.
 */
int sl_poly_solve_quadratic (double a, double b, double c,
			     double *x1, double *x2);

/* 
 * Solve for real roots of the cubic equation
 * x^3 + a x^2 + b x + c = 0, returning the number of real roots.
 */
int sl_poly_solve_cubic (double a, double b, double c,
			 double *x0, double *x1, double *x2);

#include <spar/sl_complex.h>

int sl_poly_zsolve_quadratic (double a, double b, double c, sl_complex * z0,
			      sl_complex * z1);
int sl_poly_zsolve_cubic (double a, double b, double c, sl_complex *z0, sl_complex *z1,        sl_complex *z2);


__END_DECLS
#endif /* _sl_poly_ */