#include "blas.h"double ddot_(long *n, double *sx, long *incx, double *sy, long *incy){  long i, m, nn, iincx, iincy;  double stemp;  long ix, iy;  /* forms the dot product of two vectors.        uses unrolled loops for increments equal to one.        jack dongarra, linpack, 3/11/78.        modified 12/3/93, array(1) declarations changed to array(*) */  /* Dereference inputs */  nn = *n;  iincx = *incx;  iincy = *incy;  stemp = 0.0;  if (nn > 0)  {    if (iincx == 1 && iincy == 1) /* code for both increments equal to 1 */    {      m = nn-4;      for (i = 0; i < m; i += 5)        stemp += sx[i] * sy[i] + sx[i+1] * sy[i+1] + sx[i+2] * sy[i+2] +                 sx[i+3] * sy[i+3] + sx[i+4] * sy[i+4];      for ( ; i < nn; i++)        /* clean-up loop */        stemp += sx[i] * sy[i];    }    else /* code for unequal increments or equal increments not equal to 1 */    {      ix = 0;      iy = 0;      if (iincx < 0)        ix = (1 - nn) * iincx;      if (iincy < 0)        iy = (1 - nn) * iincy;      for (i = 0; i < nn; i++)      {        stemp += sx[ix] * sy[iy];        ix += iincx;        iy += iincy;      }    }  }  return stemp;} /* ddot_ */