} /*辛普生公式求定积分，公式为：S[n]=(4*T[2*n]-T[n])/3，其中T[2n],T[n]为梯形公式计算结果*/ double Simposn(double down, double up, int n) { double s; /*辛普生公式*/ s = (4*T(down, up, 2*n) - T(down, up, n))/3; return s; } /*高斯公式求定积分*/ double Gass(double (*func)(double x), double a, double b, int n) { int i = 0; //高斯点及其求积系数列表 float x1[1]={0.0}; float A1[1]={2}; float x2[2]={-0.5573503,0.5573503}; float A2[2]={1,1}; float x3[3]={-0.7745967,0.0,0.7745967}; float A3[3]={0.555556,0.888889,0.555556}; float x4[4]={0.3399810,-0.3399810,0.8611363,-0.8611363}; float A4[4]={0.6521452,0.6521452,0.3478548,0.3478548}; float x5[5]={0.0,0.5384693,-0.5384693,0.9061799,-0.9061799}; float A5[5]={0.5688889,0.4786287,0.4786287,0.2369269,0.2369269}; float *p, *t; switch (n) { case 1: p = x1; t = A1; break; case 2: p = x2; t = A2; break; case 3: p = x3; 

t = A3; break; case 4: p = x4; t = A4; break; case 5: p = x5; t = A5; break; default : printf("intput wrong!"); } float g = 0; for (i=0; i

sum = Simposn(down, up, n); printf("辛普生公式积分值为:%f\n", sum); sum = Gass(fun, down, up, N); printf("高斯公式积分值为:%f\n", sum); return 0; }