newtoniterative.h

NewtonIterative法计算方程的解

#define PRECISION	0.0000001  
#define MAX_Number	10000 
float df( float x ) 
{
	return( 3 * x * x - 1 );
}
void NewtonIterative( )
{
	int k;
	float x0,x;
	printf("\n\n初始化值:\nx0 = ");
	scanf("%f",&x);
	// 迭代
	k = 1;
	do{
		x0 = x;
		x = x0 - f( x0 ) / df( x0 );
		printf("\nx%d=%f", k, x );
		++k;
	}while( fabs(x-x0) > PRECISION && k < MAX_Number );
	if( k >= MAX_Number )
	{
		printf("牛顿迭代失败于(k=%d)", k );
	}
	else
	{
		printf( "\n\n迭代次数 k = %d", k );
		printf( "\n根 x=%f", x );
	}
}