/*
 * $Id: Examples.java 6006 2020-03-25 11:18:52Z kredel $
 */

package edu.jas.poly;


import java.util.ArrayList;
import java.util.List;

import edu.jas.arith.BigInteger;
import edu.jas.arith.BigRational;
import edu.jas.arith.ModInteger;
import edu.jas.arith.ModIntegerRing;
import edu.jas.kern.Scripting;


/**
 * Examples for polynomials usage.
 * @author Heinz Kredel
 */

public class Examples {


    /**
     * main.
     */
    public static void main(String[] args) {
        //example0();
        /*
          example1();
          example2();
          example3();
          example4();
          example5();
        */
        //example6(); 
        example7();
        example7();
        //example8();
        //example9();
        //example10();
        //example11();
        //example12();
        //example13();
    }


    /**
     * example0. for PPPJ 2006.
     */
    public static void example0() {
        BigInteger z = new BigInteger();

        TermOrder to = new TermOrder();
        String[] vars = new String[] { "x1", "x2", "x3" };
        GenPolynomialRing<BigInteger> ring;
        ring = new GenPolynomialRing<BigInteger>(z, 3, to, vars);
        System.out.println("ring = " + ring);

        GenPolynomial<BigInteger> pol;
        pol = ring.parse("3 x1^2 x3^4 + 7 x2^5 - 61");
        System.out.println("pol = " + pol);
        System.out.println("pol = " + pol.toString(ring.getVars()));

        GenPolynomial<BigInteger> one;
        one = ring.parse("1");
        System.out.println("one = " + one);
        System.out.println("one = " + one.toString(ring.getVars()));

        GenPolynomial<BigInteger> p;
        p = pol.subtract(pol);
        System.out.println("p = " + p);
        System.out.println("p = " + p.toString(ring.getVars()));

        p = pol.multiply(pol);
        System.out.println("p = " + p);
        System.out.println("p = " + p.toString(ring.getVars()));
    }


    /**
     * example1. random polynomial with rational coefficients. Q[x_1,...x_7]
     */
    public static void example1() {
        System.out.println("\n\n example 1");

        BigRational cfac = new BigRational();
        System.out.println("cfac = " + cfac);
        String[] vars = new String[] { "x1", "x2", "x3", "x4", "x5", "x6", "x7" };
        GenPolynomialRing<BigRational> fac;
        fac = new GenPolynomialRing<BigRational>(cfac, 7, vars);
        //System.out.println("fac = " + fac);
        System.out.println("fac = " + fac);

        GenPolynomial<BigRational> a = fac.random(10);
        System.out.println("a = " + a);
    }


    /**
     * example2. random polynomial with coefficients of rational polynomials.
     * Q[x_1,...x_7][y_1,...,y_3]
     */
    public static void example2() {
        System.out.println("\n\n example 2");

        BigRational cfac = new BigRational();
        System.out.println("cfac = " + cfac);
        String[] cvars = new String[] { "x1", "x2", "x3", "x4", "x5", "x6", "x7" };
        GenPolynomialRing<BigRational> fac;
        fac = new GenPolynomialRing<BigRational>(cfac, 7, cvars);
        System.out.println("fac = " + fac);

        String[] vars = new String[] { "y1", "y2", "y3" };
        GenPolynomialRing<GenPolynomial<BigRational>> gfac;
        gfac = new GenPolynomialRing<GenPolynomial<BigRational>>(fac, 3, vars);
        System.out.println("gfac = " + gfac);

        GenPolynomial<GenPolynomial<BigRational>> a = gfac.random(10);
        System.out.println("a = " + a);
    }


    /**
     * example3. random rational algebraic number. Q(alpha)
     */
    public static void example3() {
        System.out.println("\n\n example 3");

        BigRational cfac = new BigRational();
        System.out.println("cfac = " + cfac);

        String[] vars = new String[] { "alpha" };
        GenPolynomialRing<BigRational> mfac;
        mfac = new GenPolynomialRing<BigRational>(cfac, 1, vars);
        System.out.println("mfac = " + mfac);

        GenPolynomial<BigRational> modul = mfac.random(8).monic();
        // assume !mo.isUnit()
        System.out.println("modul = " + modul);

        AlgebraicNumberRing<BigRational> fac;
        fac = new AlgebraicNumberRing<BigRational>(modul);
        System.out.println("fac = " + fac);

        AlgebraicNumber<BigRational> a = fac.random(15);
        System.out.println("a = " + a);
    }


    protected static long getPrime() {
        long prime = 2; //2^60-93; // 2^30-35; //19; knuth (2,390)
        for (int i = 1; i < 60; i++) {
            prime *= 2;
        }
        prime -= 93;
        //System.out.println("prime = " + prime);
        return prime;
    }


    /**
     * example4. random modular algebraic number. Z_p(alpha)
     */
    public static void example4() {
        System.out.println("\n\n example 4");

        long prime = getPrime();
        ModIntegerRing cfac = new ModIntegerRing(prime);
        System.out.println("cfac = " + cfac);

        String[] vars = new String[] { "alpha" };
        GenPolynomialRing<ModInteger> mfac;
        mfac = new GenPolynomialRing<ModInteger>(cfac, 1, vars);
        System.out.println("mfac = " + mfac);

        GenPolynomial<ModInteger> modul = mfac.random(8).monic();
        // assume !modul.isUnit()
        System.out.println("modul = " + modul);

        AlgebraicNumberRing<ModInteger> fac;
        fac = new AlgebraicNumberRing<ModInteger>(modul);
        System.out.println("fac = " + fac);

        AlgebraicNumber<ModInteger> a = fac.random(12);
        System.out.println("a = " + a);
    }


    /**
     * example5. random solvable polynomial with rational coefficients.
     * Q{x_1,...x_6, {x_2 * x_1 = x_1 x_2 +1, ...} }
     */
    public static void example5() {
        System.out.println("\n\n example 5");

        BigRational cfac = new BigRational();
        System.out.println("cfac = " + cfac);
        GenSolvablePolynomialRing<BigRational> sfac;
        sfac = new GenSolvablePolynomialRing<BigRational>(cfac, 6);
        //System.out.println("sfac = " + sfac);

        RelationGenerator<BigRational> wl = new WeylRelations<BigRational>();
        //wl.generate(sfac);
        sfac.addRelations(wl);
        System.out.println("sfac = " + sfac);

        GenSolvablePolynomial<BigRational> a = sfac.random(5);
        System.out.println("a = " + a);
        System.out.println("a = " + a.toString(sfac.vars));

        GenSolvablePolynomial<BigRational> b = a.multiply(a);
        System.out.println("b = " + b);
        System.out.println("b = " + b.toString(sfac.vars));

        System.out.println("sfac = " + sfac);
    }


    /**
     * example6. Fateman benchmark: p = (x+y+z)^20; q = p * (p+1) Z[z,y,x]
     */
    public static void example6() {
        System.out.println("\n\n example 6");

        BigInteger cfac = new BigInteger();
        System.out.println("cfac = " + cfac);

        TermOrder to = new TermOrder(TermOrder.INVLEX);
        System.out.println("to   = " + to);

        GenPolynomialRing<BigInteger> fac;
        fac = new GenPolynomialRing<BigInteger>(cfac, 3, to);
        System.out.println("fac = " + fac);
        fac.setVars(new String[] { "z", "y", "x" });
        System.out.println("fac = " + fac);

        GenPolynomial<BigInteger> x = fac.univariate(0);
        GenPolynomial<BigInteger> y = fac.univariate(1);
        GenPolynomial<BigInteger> z = fac.univariate(2);

        System.out.println("x = " + x);
        System.out.println("x = " + x.toString(fac.vars));
        System.out.println("y = " + y);
        System.out.println("y = " + y.toString(fac.vars));
        System.out.println("z = " + z);
        System.out.println("z = " + z.toString(fac.vars));

        GenPolynomial<BigInteger> p = x.sum(y).sum(z).sum(fac.getONE());
        //BigInteger f = cfac.fromInteger(10000000001L);
        // p = p.multiply( f );
        System.out.println("p = " + p);
        System.out.println("p = " + p.toString(fac.vars));

        GenPolynomial<BigInteger> q = p;
        for (int i = 1; i < 20; i++) {
            q = q.multiply(p);
        }
        //System.out.println("q = " + q.toString( fac.vars ) );
        System.out.println("q = " + q.length());

        GenPolynomial<BigInteger> q1 = q.sum(fac.getONE());

        GenPolynomial<BigInteger> q2;
        long t = System.currentTimeMillis();
        q2 = q.multiply(q1);
        t = System.currentTimeMillis() - t;

        System.out.println("q2 = " + q2.length());
        System.out.println("time = " + t + " ms");
    }


    /**
     * example7. Fateman benchmark: p = (x+y+z)^20; q = p * (p+1) Q[z,y,x]
     */
    public static void example7() {
        System.out.println("\n\n example 7");

        BigRational cfac = new BigRational();
        System.out.println("cfac = " + cfac);

        TermOrder to = new TermOrder(TermOrder.INVLEX);
        System.out.println("to   = " + to);

        GenPolynomialRing<BigRational> fac;
        fac = new GenPolynomialRing<BigRational>(cfac, 3, to);
        System.out.println("fac = " + fac);
        fac.setVars(new String[] { "z", "y", "x" });
        System.out.println("fac = " + fac);

        long mi = 1L;
        //long mi = Integer.MAX_VALUE;
        GenPolynomial<BigRational> x = fac.univariate(0, mi);
        GenPolynomial<BigRational> y = fac.univariate(1, mi);
        GenPolynomial<BigRational> z = fac.univariate(2, mi);

        // System.out.println("x = " + x);
        System.out.println("x = " + x.toString(fac.vars));
        // System.out.println("y = " + y);
        System.out.println("y = " + y.toString(fac.vars));
        // System.out.println("z = " + z);
        System.out.println("z = " + z.toString(fac.vars));

        GenPolynomial<BigRational> p = x.sum(y).sum(z).sum(fac.getONE());
        //BigRational f = cfac.fromInteger(10000000001L);
        // f = f.multiply( f );
        //p = p.multiply( f );
        // System.out.println("p = " + p);
        System.out.println("p = " + p.toString(fac.vars));

        int mpow = 20;
        System.out.println("mpow = " + mpow);
        GenPolynomial<BigRational> q = p;
        for (int i = 1; i < mpow; i++) {
            q = q.multiply(p);
        }
        //System.out.println("q = " + q.toString( fac.vars ) );
        System.out.println("len(q) = " + q.length());
        System.out.println("deg(q) = " + q.degree());

        GenPolynomial<BigRational> q1 = q.sum(fac.getONE());

        GenPolynomial<BigRational> q2;
        long t = System.currentTimeMillis();
        q2 = q.multiply(q1);
        t = System.currentTimeMillis() - t;

        System.out.println("len(q2)    = " + q2.length());
        System.out.println("deg(q2)    = " + q2.degree());
        System.out.println("LeadEV(q2) = " + q2.leadingExpVector());
        System.out.println("time       = " + t + " ms");
    }


    /**
     * example8. Chebyshev polynomials
     * 
     * T(0) = 1 T(1) = x T(n) = 2x * T(n-1) - T(n-2)
     */
    public static void example8() {
        int m = 10;
        BigInteger fac = new BigInteger();
        String[] var = new String[] { "x" };

        GenPolynomialRing<BigInteger> ring = new GenPolynomialRing<BigInteger>(fac, 1, var);

        List<GenPolynomial<BigInteger>> T = new ArrayList<GenPolynomial<BigInteger>>(m);

        GenPolynomial<BigInteger> t, one, x, x2, x2b;

        one = ring.getONE();
        x = ring.univariate(0);
        //x2  = ring.parse("2 x");
        //x2a = x.multiply( fac.fromInteger(2) );
        x2b = x.multiply(new BigInteger(2));
        x2 = x2b;

        T.add(one);
        T.add(x);
        for (int n = 2; n < m; n++) {
            t = x2.multiply(T.get(n - 1)).subtract(T.get(n - 2));
            T.add(t);
        }
        for (int n = 0 /*m-2*/; n < m; n++) {
            System.out.println("T[" + n + "] = " + T.get(n)); //.toString(var) );
        }
    }


    /**
     * example9. Legendre polynomials
     * 
     * P(0) = 1 P(1) = x P(n) = 1/n [ (2n-1) * x * P(n-1) - (n-1) * P(n-2) ]
     */
    // P(n+1) = 1/(n+1) [ (2n+1) * x * P(n) - n * P(n-1) ]
    public static void example9() {
        int n = 10;

        BigRational fac = new BigRational();
        String[] var = new String[] { "x" };

        GenPolynomialRing<BigRational> ring = new GenPolynomialRing<BigRational>(fac, 1, var);

        List<GenPolynomial<BigRational>> P = new ArrayList<GenPolynomial<BigRational>>(n);

        GenPolynomial<BigRational> t, one, x, xc;
        BigRational n21, nn;

        one = ring.getONE();
        x = ring.univariate(0);

        P.add(one);
        P.add(x);
        for (int i = 2; i < n; i++) {
            n21 = new BigRational(2 * i - 1);
            xc = x.multiply(n21);
            t = xc.multiply(P.get(i - 1));
            nn = new BigRational(i - 1);
            xc = P.get(i - 2).multiply(nn);
            t = t.subtract(xc);
            nn = new BigRational(1, i);
            t = t.multiply(nn);
            P.add(t);
        }
        for (int i = 0; i < n; i++) {
            System.out.println("P[" + i + "] = " + P.get(i).toString(var));
            System.out.println();
        }
    }


    /**
     * example10. Hermite polynomials
     * 
     * H(0) = 1 H(1) = 2 x H(n) = 2 * x * H(n-1) - 2 * (n-1) * H(n-2)
     */
    // H(n+1) = 2 * x * H(n) - 2 * n * H(n-1)
    public static void example10() {
        int n = 100;

        BigInteger fac = new BigInteger();
        String[] var = new String[] { "x" };

        GenPolynomialRing<BigInteger> ring = new GenPolynomialRing<BigInteger>(fac, 1, var);

        List<GenPolynomial<BigInteger>> H = new ArrayList<GenPolynomial<BigInteger>>(n);

        GenPolynomial<BigInteger> t, one, x2, xc, x;
        BigInteger n2, nn;

        one = ring.getONE();
        x = ring.univariate(0);
        n2 = new BigInteger(2);
        x2 = x.multiply(n2);
        H.add(one);
        H.add(x2);
        for (int i = 2; i < n; i++) {
            t = x2.multiply(H.get(i - 1));
            nn = new BigInteger(2 * (i - 1));
            xc = H.get(i - 2).multiply(nn);
            t = t.subtract(xc);
            H.add(t);
        }
        for (int i = n - 1; i < n; i++) {
            System.out.println("H[" + i + "] = " + H.get(i).toString(var));
            System.out.println();
        }
    }


    /**
     * example11. degree matrix;
     * 
     */
    @SuppressWarnings("cast")
    public static void example11() {
        int n = 50;
        BigRational fac = new BigRational();
        GenPolynomialRing<BigRational> ring = new GenPolynomialRing<BigRational>(fac, n);
        System.out.println("ring = " + ring + "\n");

        GenPolynomial<BigRational> p = ring.random(5, 3, 6, 0.5f);
        System.out.println("p = " + p + "\n");

        List<GenPolynomial<BigInteger>> dem = TermOrderOptimization.<BigRational> degreeMatrix(p);

        System.out.println("dem = " + dem + "\n");

        List<GenPolynomial<BigRational>> polys = new ArrayList<GenPolynomial<BigRational>>();
        polys.add(p);
        for (int i = 0; i < 5; i++) {
            polys.add(ring.random(5, 3, 6, 0.1f));
        }
        System.out.println("polys = " + polys + "\n");

        dem = TermOrderOptimization.<BigRational> degreeMatrix(polys);
        System.out.println("dem = " + dem + "\n");

        List<Integer> perm;
        perm = TermOrderOptimization.optimalPermutation(dem);
        System.out.println("perm = " + perm + "\n");

        List<GenPolynomial<BigInteger>> pdem;
        pdem = TermOrderOptimization.<GenPolynomial<BigInteger>> listPermutation(perm, dem);
        System.out.println("pdem = " + pdem + "\n");

        GenPolynomialRing<BigRational> pring;
        pring = TermOrderOptimization.<BigRational> permutation(perm, ring);
        System.out.println("ring  = " + ring);
        System.out.println("pring = " + pring + "\n");

        List<GenPolynomial<BigRational>> ppolys;
        ppolys = TermOrderOptimization.<BigRational> permutation(perm, pring, polys);
        System.out.println("ppolys = " + ppolys + "\n");

        dem = TermOrderOptimization.<BigRational> degreeMatrix(ppolys);
        //System.out.println("pdem = " + dem + "\n");

        perm = TermOrderOptimization.optimalPermutation(dem);
        //System.out.println("pperm = " + perm + "\n");
        int i = 0;
        for (Integer j : perm) {
            if (i != (int) j) {
                System.out.println("error = " + i + " != " + j + "\n");
            }
            i++;
        }

        OptimizedPolynomialList<BigRational> op;
        op = TermOrderOptimization.<BigRational> optimizeTermOrder(ring, polys);
        System.out.println("op:\n" + op);
        if (!op.equals(new PolynomialList<BigRational>(pring, ppolys))) {
            System.out.println("error = " + "\n" + op);
        }
    }


    /**
     * example12. type games.
     */
    public static void example12() {
        System.out.println("\n\n example 12");

        BigRational t1 = new BigRational();
        System.out.println("t1 = " + t1);

        BigInteger t2 = new BigInteger();
        System.out.println("t2 = " + t2);

        System.out.println("t1.isAssignableFrom(t2) = " + t1.getClass().isAssignableFrom(t2.getClass()));
        System.out.println("t2.isAssignableFrom(t1) = " + t2.getClass().isAssignableFrom(t1.getClass()));

        String[] vars = new String[] { "x1", "x2", "x3" };
        GenPolynomialRing<BigInteger> t3 = new GenPolynomialRing<BigInteger>(t2, 3, vars);
        System.out.println("t3 = " + t3);

        GenSolvablePolynomialRing<BigInteger> t4 = new GenSolvablePolynomialRing<BigInteger>(t2, vars);
        System.out.println("t4 = " + t4);

        System.out.println("t3.isAssignableFrom(t4) = " + t3.getClass().isAssignableFrom(t4.getClass()));
        System.out.println("t4.isAssignableFrom(t3) = " + t4.getClass().isAssignableFrom(t3.getClass()));

        GenPolynomialRing<BigRational> t5 = new GenPolynomialRing<BigRational>(t1, 3, vars);
        System.out.println("t5 = " + t5);

        System.out.println("t3.isAssignableFrom(t5) = " + t3.getClass().isAssignableFrom(t5.getClass()));
        System.out.println("t5.isAssignableFrom(t3) = " + t5.getClass().isAssignableFrom(t3.getClass()));
    }


    /**
     * example13. poly parser for strange syntax.
     */
    public static void example13() {
        System.out.println("\n\n example 13");
        TermOrder to = new TermOrder(TermOrder.INVLEX);
        BigRational cfraction = new BigRational(1);
        String[] vars = new String[] { "x" };

        //Scripting.setPrecision(5);

        GenPolynomialRing<BigRational> pfac 
            = new GenPolynomialRing<BigRational>(cfraction, 1, to, vars);
        GenPolynomial<BigRational> FF0 = pfac.parse("19(6)/10");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("19(6)1/10");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("19 6/10");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("19*6/10");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("19+6/10");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("(x).2");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("4.0/9.0");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("4/9.0");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("4.0/9");
        System.out.println("FF0 = " + FF0);
        FF0 = pfac.parse("-4.0/9");
        System.out.println("FF0 = " + FF0);
    }
}