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📄 d9r8af.java

📁 解具有导数的多元函数的无约束极小值点或具有导数的非线性方程组的近似解
💻 JAVA
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public class d9r8aF
{
	double fgauss_y; 
	void fgauss(double x, double a[], double y, double dyda[], int na)
	{
		y = 0.0;
        for (int i = 1; i <= na - 1; i = i + 3)
		{
			double arg = (x - a[i + 1]) / a[i + 2];
			double ex = Math.exp(-(arg * arg));
			double fac = a[i] * ex * 2.0 * arg;
			y = y + a[i] * ex;
			dyda[i] = ex;
			dyda[i + 1] = fac / a[i + 2];
			dyda[i + 2] = fac * arg / a[i + 2];
		}
        fgauss_y = y;
	}
		
	double mrqcof_chisq;
	void mrqcof(double x[], double y[], double sig[], int ndata, double a[],
    int ma, int lista[], int mfit, double alpha[], double beta[],
    int nalp, double chisq)
	{
        int i, j, k;
        double wt, ymod, sig2i, dy;
        double  dyda[] = new double[21];
        ymod = 0;
        for (j = 1; j <= mfit; j++)
		{
            for (k = 1; k <= j; k++)
            {
                alpha[(j - 1) * nalp + k] = 0.0;
            }
            beta[j] = 0.0;
        }
        chisq = 0.0;
        for (i = 1; i <= ndata; i++)
		{
            fgauss(x[i], a, ymod, dyda, ma);
            ymod = fgauss_y;
            sig2i = 1.0 / (sig[i] * sig[i]);
            dy = y[i] - ymod;
            for (j = 1; j <= mfit; j++)
			{
                wt = dyda[lista[j]] * sig2i;
                for (k = 1; k <= j; k++)
				{
                    alpha[(j - 1) * nalp + k] = alpha[(j - 1) * nalp + k] + wt * dyda[lista[k]];
                }
                beta[j] = beta[j] + dy * wt;
            }
            chisq = chisq + dy * dy * sig2i;
        }
        for (j = 2; j <= mfit; j++)
		{
            for (k = 1; k <= j - 1; k++)
            {
                alpha[(k - 1) * nalp + j] = alpha[(j - 1) * nalp + k];
            }
        }
        mrqcof_chisq = chisq;
	}
	
    static int kk, i, j, k, ihit;
	static double ochisq;
	double mrqmin_chisq;
	double mrqmin_alamda;
    static double atry[] = new double[21];
    static double beta[] = new double[21];
    static double da[] = new double[21];
	void mrqmin(double x[], double y[], double sig[], int ndata, double a[],
    int ma, int lista[], int mfit, double covar[], double alpha[],
    int nca, double chisq, double alamda)
	{
		//double ochisq=0;
		if (alamda < 0.0)
		{
            kk = mfit + 1;
            for (j = 1; j <= ma; j++)
			{
                ihit = 0;
                for (k = 1; k <= mfit; k++)
				{
                    if (lista[k] == j)
					{
						ihit = ihit + 1;
					}
                }
                if (ihit == 0)
				{
                    lista[kk] = j;
                    kk = kk + 1;
				}
                else
				{
					if (ihit > 1)
					{
						System.out.println ("improper permutation in lista");
						System.exit(1);
					}
                }
            }
            if (kk != ma + 1)
			{
				System.out.println ("improper permutation in lista");
				System.exit(1);
			}
            alamda = 0.001;
            mrqcof(x, y, sig, ndata, a, ma, lista, mfit, alpha, beta, nca, chisq);
            chisq = mrqcof_chisq;
            ochisq = chisq;
            for (j = 1; j <= ma; j++)
			{
                atry[j] = a[j];
            }
		}
        for (j = 1; j <= mfit; j++)
		{
            for (k = 1; k <= mfit; k++)
            {
                covar[(j - 1) * nca + k] = alpha[(j - 1) * nca + k];
            }
            covar[(j - 1) * nca + j] = alpha[(j - 1) * nca + j] * (1.0 + alamda);
            da[j] = beta[j];
		}
		gaussj(covar, mfit, nca, da);
		if (alamda == 0.0)
		{
            covsrt(covar, nca, ma, lista, mfit);
            for (i = 1; i <= 20; i++)
			{
                da[i] = 0;
                atry[i] = 0;
			}
            mrqmin_chisq = chisq; mrqmin_alamda = alamda;
            return;
		}
        for (j = 1; j <= mfit; j++)
		{
            atry[lista[j]] = a[lista[j]] + da[j];
		}
		mrqcof(x, y, sig, ndata, atry, ma, lista, mfit, covar, da, nca, chisq);
        chisq = mrqcof_chisq;
		if (chisq < ochisq)
		{
            alamda = 0.1 * alamda;
            ochisq = chisq;
            for (j = 1; j <= mfit; j++)
            {
                for (k = 1; k <= mfit; k++)
				{
                    alpha[(j - 1) * nca + k] = covar[(j - 1) * nca + k];
                }
                beta[j] = da[j];
                int temp = lista[j];
                a[temp] = atry[temp];
                //a[lista[j]] = atry[lista[j]];
            }
		}
		else
		{
            alamda = 10.0 * alamda;
            chisq = ochisq;
		}
        for (i=1; i <= 20; i++)
		{
            da[i] = 0;
            atry[i] = 0;
		}
        mrqmin_chisq = chisq; mrqmin_alamda = alamda;
	}

	static int iset;
	static double gset;
	int gasdev_idum;
	double gasdev(int idum)
	{		
        double t, v1, v2, fac, r;
        if (iset == 0.0)
		{
            do
            {
				v1 = 2.0 * ran1(idum) - 1.0;
				idum = ran1_idum;
				v2 = 2.0 * ran1(idum) - 1.0;
				idum = ran1_idum;
                r = v1 * v1 + v2 * v2;
			}while ((r >= 1.0) || (r == 0.0));
			fac = Math.sqrt(-2.0 * Math.log(r) / r);
			gset = v1 * fac;
			t = v2 * fac;
			iset = 1;
			gasdev_idum = idum;
			return t;
		}
        else
		{
			t = gset;
			gasdev_idum = idum;
			iset = 0;
			return t;
        }
	}

	void covsrt(double covar[], int ncvm, int ma, int lista[], int mfit)
	{
		int i, j;
		double swap;
		for (j = 1; j <= ma - 1; j++)
		{
			for (i = j + 1; i <= ma; i++)
			{
                covar[(i - 1) * ma + j] = 0.0;
			}
        }
        for (i = 1; i <= mfit - 1; i++)
		{
            for (j = i + 1; j <= mfit; j++)
			{
                if (lista[j] > lista[i])
				{
                    covar[(lista[j] - 1) * ma + lista[i]] = covar[(i - 1) * ma + j];
				}
                else
				{
                    covar[(lista[i] - 1) * ma + lista[j]] = covar[(i - 1) * ma + j];
                }
            }
        }
        swap = covar[1];;
        for (j = 1; j <= ma; j++)
		{
            covar[j] = covar[(j - 1) * ma + j];
            covar[(j - 1) * ma + j] = 0.0;
        }
        covar[(lista[1] - 1) * ma + lista[1]] = swap;
        for (j = 2; j <= mfit; j++)
		{
            covar[(lista[j] - 1) * ma + lista[j]] = covar[j];
        }
        for (j = 2; j <= ma; j++)
		{
            for (i = 1; i <= j - 1; i++)
			{
                covar[(i - 1) * ma + j] = covar[(j - 1) * ma + i];
			}
		}
	}

	void gaussj(double A[], int N, int MA,double B[])
	{
		int i, j, k, l ,ll, IROW, ICOL;
		double BIG,PIVINV,DUM;
        int IPIV[] = new int[51];
		int INDXR[] = new int[51];
		int INDXC[] =  new int[51];
        ICOL = 0;
		IROW = 0;
        for (j = 1; j <= N; j++)
		{
            IPIV[j] = 0;
        }
        for (i = 1; i <= N; i++)
		{
            BIG = 0.0;
            for (j = 1; j <= N; j++)
			{
                if(IPIV[j] != 1)
				{
                    for(k = 1; k <= N; k++)
					{
                        if(IPIV[k] == 0)
						{
                            if(Math.abs(A[(j - 1) * MA + k]) >= BIG)
							{
                                BIG = Math.abs(A[(j - 1) * MA + k]);
								IROW = j;
								ICOL = k;
							}
							else if(IPIV[k] > 1)
							{
								System.out.println("Singular matrix");
								System.exit(1);
							}
						}
                    }
                }
            }
            IPIV[ICOL]=IPIV[ICOL] + 1;
            if(IROW != ICOL)
			{
                for (l = 1; l <= N; l++)
				{
                    DUM = (A[(IROW - 1) * MA + l]);
                    A[(IROW - 1) * MA + l] = A[(ICOL - 1) * MA + l];
                    A[(ICOL - 1) * MA + l] = DUM;
                }
                DUM = B[IROW];
                B[IROW] = B[ICOL];
                B[ICOL] = DUM;
            }
            INDXR[i] = IROW;
            INDXC[i] = ICOL;
            if(A[(ICOL - 1) * MA + ICOL] == 0.0)
			{
				System.out.println("Singular matrix");
				System.exit(1);
			}
            PIVINV = 1.0 / (A[(ICOL - 1) * MA + ICOL]);
            A[(ICOL - 1) * MA + ICOL] = 1.0;
            for (l = 1; l <= N; l++)
			{
                A[(ICOL - 1) * MA + l] = A[(ICOL - 1) * MA + l] * PIVINV;
            }
            B[ICOL] = B[ICOL] * PIVINV;
            for (ll = 1; ll <= N; ll++)
            {
                if(ll != ICOL)
				{
                    DUM = A[(ll - 1) * MA + ICOL];
                    A[(ll - 1) * MA + ICOL] = 0.0;
                    for(l = 1; l <= N; l++)
					{
                        A[(ll - 1) * MA + l] = A[(ll - 1) * MA + l] - A[(ICOL - 1) * MA + l] * DUM;
                    }
                    B[ll] = B[ll] - B[ICOL] * DUM;
                }
            }
		}	
        for (l = N; l >= 1; l--)
		{
            if(INDXR[l] != INDXC[l])
			{
                for (k = 1; k <= N; k++)
                {
                    DUM = A[(k - 1) * MA + INDXR[l]];
                    A[(k - 1) * MA + INDXR[l]] = A[(k - 1) * MA + INDXC[l]];
                    A[(k - 1) * MA + INDXR[l]] = DUM;
                }
            }
        }
	}

	int ran1_idum;
	static double r[] = new double[98];
	static int ix1, ix2, ix3;
	static int iff;
	double ran1(int idum)
	{
        double rm1, rm2, t;
		int m1, m2, m3, ia1, ia2, ia3, ic1, ic2, ic3, j;		 
        m1 = 259200; ia1 = 7141; ic1 = 54773; rm1 = 0.0000038580247;
        m2 = 134456; ia2 = 8121; ic2 = 28411; rm2 = 0.0000074373773;
        m3 = 243000; ia3 = 4561; ic3 = 51349;
        if ((idum < 0) || (iff == 0))
		{
            iff = 1;
            ix1 =  (ic1 - idum) % m1;
            ix1 = (ia1 * ix1 + ic1) % m1;
            ix2 = ix1 % m2;
            ix1 = (ia1 * ix1 + ic1) % m1;
            ix3 = ix1 % m3;
            for (j = 1; j <= 97; j++)
			{
                ix1 = (ia1 * ix1 + ic1) % m1;
                ix2 = (ia2 * ix2 + ic2) % m2;
                r[j] = ((double)ix1 + (double)ix2 * rm2) * rm1;
            }
            idum = 1;
		}
        ix1 = (ia1 * ix1 + ic1) % m1;
        ix2 = (ia2 * ix2 + ic2) % m2;
        ix3 = (ia3 * ix3 + ic3) % m3;
        j = 1 + (int)((97 * ix3) / m3);
        if ((j > 97) || (j < 1)) 
        {
            System.out.println( "abnormal exit");
            System.exit(1);
        }
        t = r[j];
        r[j] = ((double)ix1 + (double)ix2 * rm2) * rm1;
        ran1_idum = idum;
        return t;
	}
}

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