#include "blaswrap.h"
#include "f2c.h"

/* Subroutine */ int sgeequ_(integer *m, integer *n, real *a, integer *lda, 
	real *r__, real *c__, real *rowcnd, real *colcnd, real *amax, integer 
	*info)
{
/*  -- LAPACK routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       March 31, 1993   


    Purpose   
    =======   

    SGEEQU computes row and column scalings intended to equilibrate an   
    M-by-N matrix A and reduce its condition number.  R returns the row   
    scale factors and C the column scale factors, chosen to try to make   
    the largest element in each row and column of the matrix B with   
    elements B(i,j)=R(i)*A(i,j)*C(j) have absolute value 1.   

    R(i) and C(j) are restricted to be between SMLNUM = smallest safe   
    number and BIGNUM = largest safe number.  Use of these scaling   
    factors is not guaranteed to reduce the condition number of A but   
    works well in practice.   

    Arguments   
    =========   

    M       (input) INTEGER   
            The number of rows of the matrix A.  M >= 0.   

    N       (input) INTEGER   
            The number of columns of the matrix A.  N >= 0.   

    A       (input) REAL array, dimension (LDA,N)   
            The M-by-N matrix whose equilibration factors are   
            to be computed.   

    LDA     (input) INTEGER   
            The leading dimension of the array A.  LDA >= max(1,M).   

    R       (output) REAL array, dimension (M)   
            If INFO = 0 or INFO > M, R contains the row scale factors   
            for A.   

    C       (output) REAL array, dimension (N)   
            If INFO = 0,  C contains the column scale factors for A.   

    ROWCND  (output) REAL   
            If INFO = 0 or INFO > M, ROWCND contains the ratio of the   
            smallest R(i) to the largest R(i).  If ROWCND >= 0.1 and   
            AMAX is neither too large nor too small, it is not worth   
            scaling by R.   

    COLCND  (output) REAL   
            If INFO = 0, COLCND contains the ratio of the smallest   
            C(i) to the largest C(i).  If COLCND >= 0.1, it is not   
            worth scaling by C.   

    AMAX    (output) REAL   
            Absolute value of largest matrix element.  If AMAX is very   
            close to overflow or very close to underflow, the matrix   
            should be scaled.   

    INFO    (output) INTEGER   
            = 0:  successful exit   
            < 0:  if INFO = -i, the i-th argument had an illegal value   
            > 0:  if INFO = i,  and i is   
                  <= M:  the i-th row of A is exactly zero   
                  >  M:  the (i-M)-th column of A is exactly zero   

    =====================================================================   


       Test the input parameters.   

       Parameter adjustments */
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;
    real r__1, r__2, r__3;
    /* Local variables */
    static integer i__, j;
    static real rcmin, rcmax;
    extern doublereal slamch_(char *);
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static real bignum, smlnum;
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]

    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --r__;
    --c__;

    /* Function Body */
    *info = 0;
    if (*m < 0) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*m)) {
	*info = -4;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SGEEQU", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0) {
	*rowcnd = 1.f;
	*colcnd = 1.f;
	*amax = 0.f;
	return 0;
    }

/*     Get machine constants. */

    smlnum = slamch_("S");
    bignum = 1.f / smlnum;

/*     Compute row scale factors. */

    i__1 = *m;
    for (i__ = 1; i__ <= i__1; ++i__) {
	r__[i__] = 0.f;
/* L10: */
    }

/*     Find the maximum element in each row. */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
	i__2 = *m;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing MAX */
	    r__2 = r__[i__], r__3 = (r__1 = a_ref(i__, j), dabs(r__1));
	    r__[i__] = dmax(r__2,r__3);
/* L20: */
	}
/* L30: */
    }

/*     Find the maximum and minimum scale factors. */

    rcmin = bignum;
    rcmax = 0.f;
    i__1 = *m;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* Computing MAX */
	r__1 = rcmax, r__2 = r__[i__];
	rcmax = dmax(r__1,r__2);
/* Computing MIN */
	r__1 = rcmin, r__2 = r__[i__];
	rcmin = dmin(r__1,r__2);
/* L40: */
    }
    *amax = rcmax;

    if (rcmin == 0.f) {

/*        Find the first zero scale factor and return an error code. */

	i__1 = *m;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    if (r__[i__] == 0.f) {
		*info = i__;
		return 0;
	    }
/* L50: */
	}
    } else {

/*        Invert the scale factors. */

	i__1 = *m;
	for (i__ = 1; i__ <= i__1; ++i__) {
/* Computing MIN   
   Computing MAX */
	    r__2 = r__[i__];
	    r__1 = dmax(r__2,smlnum);
	    r__[i__] = 1.f / dmin(r__1,bignum);
/* L60: */
	}

/*        Compute ROWCND = min(R(I)) / max(R(I)) */

	*rowcnd = dmax(rcmin,smlnum) / dmin(rcmax,bignum);
    }

/*     Compute column scale factors */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
	c__[j] = 0.f;
/* L70: */
    }

/*     Find the maximum element in each column,   
       assuming the row scaling computed above. */

    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
	i__2 = *m;
	for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing MAX */
	    r__2 = c__[j], r__3 = (r__1 = a_ref(i__, j), dabs(r__1)) * r__[
		    i__];
	    c__[j] = dmax(r__2,r__3);
/* L80: */
	}
/* L90: */
    }

/*     Find the maximum and minimum scale factors. */

    rcmin = bignum;
    rcmax = 0.f;
    i__1 = *n;
    for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
	r__1 = rcmin, r__2 = c__[j];
	rcmin = dmin(r__1,r__2);
/* Computing MAX */
	r__1 = rcmax, r__2 = c__[j];
	rcmax = dmax(r__1,r__2);
/* L100: */
    }

    if (rcmin == 0.f) {

/*        Find the first zero scale factor and return an error code. */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    if (c__[j] == 0.f) {
		*info = *m + j;
		return 0;
	    }
/* L110: */
	}
    } else {

/*        Invert the scale factors. */

	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
/* Computing MIN   
   Computing MAX */
	    r__2 = c__[j];
	    r__1 = dmax(r__2,smlnum);
	    c__[j] = 1.f / dmin(r__1,bignum);
/* L120: */
	}

/*        Compute COLCND = min(C(J)) / max(C(J)) */

	*colcnd = dmax(rcmin,smlnum) / dmin(rcmax,bignum);
    }

    return 0;

/*     End of SGEEQU */

} /* sgeequ_ */

#undef a_ref