I'm trying to make a Simpsons Rule Function Myself

Question

Jack Bush 2018-12-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/435603-i-m-trying-to-make-a-simpsons-rule-function-myself

评论： Walter Roberson 2018-12-15

I've had a few attempts at this question and have developed my answer further each time. If people wouldn't mind giving feedback or correcting my code that'd be great.

This is the question:

and the code I have written to answer this is, there is more to th question but this is just my code for the first bit:

function [y] =MPR_Asgn4_Q4a_26024405(f,a,b,n)
h=(b-a)/n;
x=zeros(1,n+1);
x(1)=a;
x(n+1)=b;
s1=0;
s2=0;
s3=0;
for k = 2:n
    x(k)=a+h*(1i-1);
end
for k=1:n/2
    s1= s1 + f(x(2*1i-1));
end
for k=1:n/2
    s2=s2+f(x(2*1i));  
end
for k= 1:n/2
    s3 = s3 +f(x(2*1i+1));
end
    
y = (h/3)*(s1+(4*s2)+s3);
disp(y);
end

2 个评论
显示无隐藏无

Omer Yasin Birey 2018-12-14

Hi Jack,

I tried to understand your code and the formula together. However, firstly I believe your "i" usages are quite wrong. If you put "i" or "j" without multiplication sign (*) that gives complexity to the number. However, if Im not wrong there is no calculations in complex domain here. Secondly, you are using loops without using the loop indexes maybe you meant "k" instead of "i"?

Walter Roberson 2018-12-15

Please do not close questions that have answers.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Omer Yasin Birey 2018-12-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/435603-i-m-trying-to-make-a-simpsons-rule-function-myself#answer_352331

编辑：Omer Yasin Birey 2018-12-14

在 MATLAB Online 中打开

Hi Jack,

I fixed your code as much as I can. You can use the code below:

function [y] =MPR_Asgn4_Q4a_26024405(f,a,b,n)
    x = linspace(a,b,n);
    x(1)=a;
    x(n+1)=b;
    h=(b-a)/n;
    s1=0;
    s2=0;
    s3=0;
    %First if statements is to check if f is an anonymous function  
    %or an array.
    
    if length(f) >  1%array state
        %if it is a array your sub intervals will be the length of array
        %So you have to update it.
        n = length(f)-1;
        h=(b-a)/n;
        for k=3:2:length(f)-2
            s1= s1 + 2*f(k);
        end
        for k=2:2:length(f)
              s2=s2+f(k);
        end
        s3 = f(length(f));
        y = (h/3)*(f(1)+(2*s1+(4*s2)+s3));
    else%anonymous function state
        
        for k=3:2:length(f)-2
            s1= s1 + 2*f(x(k));
        end
        for k=3:2:length(f)
              s2=s2+f(x(k));
        end
        s3 = f(length(f));
        y = (h/3)*(f(x(1))+(2*s1+(4*s2)+s3));
    end
    disp(y);
end