simp2.cpp

Visual C++ 常用数值算法集 源代码

void simp2(double a[], int m, int n, int mp, int np, int l2[],
		   int nl2, int& ip, int kp, double& q1)
{
    double q,qp,q0,eps = 0.000001;
    ip = 0;
    int i,ii,k,flag = 0;
    for (i = 1; i<=nl2; i++)
	{
        if (a[l2[i]*np+kp + 1] < -eps)
		{
			flag = 1;
		}
        if (flag == 1)
		{
			break;
		}
    }
    if (flag == 0)
	{
		return;
	}
    q1 = -a[l2[i]*np+ 1] / a[l2[i]*np + kp + 1];
    ip = l2[i];
    for (i = i + 1; i<=nl2; i++)
	{
        ii = l2[i];
        if (a[ii*np+kp + 1] < -eps)
		{
            q = -a[ii*np+1] / a[ii*np+kp+1];
            if (q < q1)
			{
                ip = ii;
                q1 = q;
			}
            else
			{
				if (q == q1)
				{
					for (k = 1; k<=n; k++)
					{
						qp = -a[ip*np+k + 1] / a[ip*np+kp + 1];
						q0 = -a[ii*np+k + 1] / a[ii*np+kp + 1];
						if (q0 != qp)
						{
							break;
						}
					}
					if (q0 < qp)
					{
						ip = ii;
					}
				}
            }
        }
    }
}