ex4.m

来自「数值分析, 同济大学教材<<现代数值数学和计算>>数值分」· M 代码 · 共 46 行

syms symbol_x; 
f1 = sqrt(4-(sin(symbol_x))^2); 
f2 = sin(symbol_x) / symbol_x; 
f3 = exp(symbol_x) / (4+symbol_x^2); 
syms A1;
syms A2; 
syms A3;

for i = 1 : 9 
  A1(i,1)=trapezoid_integration(f1, i, 0, 1/4);
  A1(i,2)=simpson_integration(f1,i,0,1/4); 
  
  A2(i,1)=trapezoid_integration(f2,i,1e-9,1); 
  A2(i,2)=simpson_integration(f2,i,1e-9,1); 
  
  A3(i,1)=trapezoid_integration(f3,i,0,1);   
  A3(i,2)=simpson_integration(f3,i,0,1); 
end 

k=10; 
for i=10:10:100 
  A1(k,1)=trapezoid_integration(f1,i,0,1/4); 
  A1(k,2)=simpson_integration(f1,i,0,1/4); 
  
  A2(k,1)=trapezoid_integration(f2,i,1e-9,1); 
  A2(k,2)=simpson_integration(f2,i,1e-9,1); 
  
  A3(k,1)=trapezoid_integration(f3,i,0,1); 
  A3(k,2)=simpson_integration(f3,i,0,1); 
  
  k=k+1; 
end 

%syms x;IS=int('sqrt(4-sin(x)^2)','x',0,1/4); 
IS(1)=int(f1,symbol_x,0,1/4); 
vpa(IS(1)) 
IS(2)=int(f2,symbol_x,0,1); 
vpa(IS(2)) 
IS(3)=int(f3,symbol_x,0,1); 
vpa(IS(3)) 

result1=A1; 
result2=A2; 
result3=A3;