Question

雅克比迭代法求解线性方程组的C语言程序?

Answer 1

void Solve ( double dCoef [] ,double dY [] ,unsigned int iOrder ,double dErr)

{//用Jacobi迭代法解方程组,dCoef[]系数阵,Y[]向量,iOrder给出方程阶数,dErr给出精度

x05double res [Max];x05//方程解

x05double res2[Max];x05//保存上一阶方程解

x05if ( Max < iOrder )

x05{

x05x05printf ("最多支持%d阶方程组.",Max);

x05x05return;

x05}

x05for ( unsigned int i = 0 ; i < iOrder ; res2 [i++] = 0.0 );x05//初始解向量 (0,0...)

x05

x05while ( true )

x05{

x05x05bool bStopIterative = true;x05

x05x05for (unsigned int i = 0 ; i < iOrder ; ++i)

x05x05{

x05x05x05double dSum2 = 0;

x05x05x05for (unsigned int j = 0 ; j < iOrder ; j++)

x05x05x05{//求第二项

x05x05x05x05if ( j == i ) continue;

x05x05x05x05dSum2 += dCoef [i * iOrder + j] * res2 [j];

x05x05x05}

x05x05x05res[i] = 1/dCoef[i * iOrder + i] * ( dY[i] - dSum2 );

x05x05x05

x05x05x05if ( abs ( res2[i] - res [i] ) > dErr )

x05x05x05x05bStopIterative = false;

x05x05}

x05x05

x05x05if ( bStopIterative )

x05x05x05break;

x05x05for (unsigned int i = 0 ; i < iOrder ; i++ )

x05x05x05res2[ i ] = res[ i ];

x05}

x05//输出结果

x05for (unsigned int i = 0 ; i < iOrder ; i++)

x05x05printf ("x%d = %lfn",i+1 ,res[i]);

}

int main(int argc,char* argv[])

{

x05double a[] =

x05{

x05x058,-3,2,

x05x054,11,-1,

x05x052,1,4

x05};

x05double b[3] =

x05{

x05x0520,33,12

x05};

x05Solve ( a ,b ,15 ,1e-10);

x05getchar();

x05return 0;

}