/home/bes3soft/bes3soft/Boss/7.0.2/dist/7.0.2/Reconstruction/MdcPatRec/MdcxReco/MdcxReco-00-01-59/MdcxReco/Mdcxmatinv.h File Reference

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Functions
int	Mdcxmatinv (double *array, int *norder, double *det)

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Function Documentation

int Mdcxmatinv	(	double *	array,
		int *	norder,
		double *	det
	)

Definition at line 7 of file Mdcxmatinv.cxx.

References genRecEmupikp::i, and ganga-rec::j.

Referenced by MdcxFittedHel::DoFit().

                                                              {
    /* System generated locals */
    int i__3;
    double d__1;

    /* Local variables */
    const int nmax = 10;
//    cout << "norder in Mdcxmatinv = " << *norder << endl;
    if (*norder > nmax){
     cout << "In Mdcxmatinv, norder ( = " << *norder << " ) > nmax ( = "
          << nmax << " ); error" << endl; return 1000;
    }
    static double amax, save;
    static int i, j, k, l, ik[nmax], jk[nmax];

    /* Parameter adjustments */
    array -= (nmax+1);

    /* Function Body */
    *det = (double)1.;
    for (k = 1; k <= *norder; ++k) {

/*       FIND LARGEST ELEMENT ARRAY(I, J) IN REST OF MATRIX */

        amax = (double)0.;
L21:
        for (i = k; i <= *norder; ++i) {
            for (j = k; j <= *norder; ++j) {
                d__1 = array[i + j * nmax]; 
                if ((fabs(amax)-fabs(d__1)) <= 0.) {
                        amax = array[i + j * nmax];
                        ik[k - 1] = i;
                        jk[k - 1] = j;
                }
            }
        }

/*       INTERCHANGE ROWS AND COLUMNS TO PUT AMAX IN ARRAY(K, K) */

        if (amax == 0.) {*det = (double)0.; return 1001;}

        i = ik[k - 1];
        if ((i__3 = i - k) < 0) {
            goto L21;
        } else if (i__3 == 0) {
            goto L51;
        } else {
            goto L43;
        }
L43:
        for (j = 1; j <= *norder; ++j) {
            save = array[k + j * nmax];
            array[k + j * nmax] = array[i + j * nmax];
            array[i + j * nmax] = -save;
        }
L51:
        j = jk[k - 1];
        if ((i__3 = j - k) < 0) {
            goto L21;
        } else if (i__3 == 0) {
            goto L61;
        } else {
            goto L53;
        }
L53:
        for (i = 1; i <= *norder; ++i) {
            save = array[i + k * nmax];
            array[i + k * nmax] = array[i + j * nmax];
            array[i + j * nmax] = -save;
        }

/*       ACCUMULATE ELEMENTS OF INVERSE MATRIX */

L61:
        for (i = 1; i <= *norder; ++i) {
            if (i - k != 0) {
                array[i + k * nmax] = -array[i + k * nmax] / amax;
            }   
        }
        for (i = 1; i <= *norder; ++i) {
            for (j = 1; j <= *norder; ++j) {
                if (i - k != 0) {
                    goto L74;
                } else {
                    goto L80;
                }
L74:
                if (j - k != 0) {
                    goto L75;
                } else {
                    goto L80;
                }
L75:
                array[i+j*nmax] += array[i+k*nmax] * array[k+j*nmax];
L80:
                ;
            }
        }
        for (j = 1; j <= *norder; ++j) {
            if (j - k != 0) {
                    array[k + j * nmax] /= amax;
            }
        }
        array[k + k * nmax] = (double)1. / amax;
        *det *= amax;
    }

/*       RESTORE ORDERING OF MATRIX */

    for (l = 1; l <= *norder; ++l) {
        k = *norder - l + 1;
        j = ik[k - 1];
        if (j - k <= 0) {
            goto L111;
        } else {
            goto L105;
        }
L105:
        for (i = 1; i <= *norder; ++i) {
            save = array[i + k * nmax];
            array[i + k * nmax] = -array[i + j * nmax];
            array[i + j * nmax] = save;
        }
L111:
        i = jk[k - 1];
        if (i - k <= 0) {
            goto L130;
        } else {
            goto L113;
        }
L113:
        for (j = 1; j <= *norder; ++j) {
            save = array[k + j * nmax];
            array[k + j * nmax] = -array[i + j * nmax];
            array[i + j * nmax] = save;
        }
L130:
        ;
    }
    return 0;
} /* Mdcxmatinv */

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