Summation In Matlab With Vectors

Question

Irem Sara 2022-2-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1649490-summation-in-matlab-with-vectors

评论： Irem Sara 2022-2-17

I am trying to compute a summation over 1:N, and the expression is below:

I already defined the vectors = s11 and = smat and $Y_{dt}= Yd;

Any help would be appreciated! Thanks a lot

2 个评论
显示无隐藏无

Simon Dengler 2022-2-14

maby this helps: https://de.mathworks.com/help/matlab/ref/sum.html

Irem Sara 2022-2-14

编辑：Irem Sara 2022-2-14

在 MATLAB Online 中打开

I am not sure if the latex code was showing, but the issue is I tried using the below code:

I get an error "Array indices must be positive integers or logical values." And I am not sure if the code is what is described in the summation.

for i=1:N
    chi(i,1)= sum(beta^(i+1)*gamma/s11(i,1) *(840*(1+eta)*exp(xi*Yd(i,1)-(1+eta)*smat(i,1))/(1+exp(xi*Yd(i,1)-(1+eta)*smat(i,1))))^(i-1));
end 

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

David Hill 2022-2-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1649490-summation-in-matlab-with-vectors#answer_895700

在 MATLAB Online 中打开

No loop needed. Need to examine each array (s11,Yd,smat) and ensure they have the necessary elements (at least N). Recommend not using 'i' to index (something it can be confused for complex number).

I=(1:N)';
chi(I,1)= sum(beta.^(I+1)*gamma./s11(I,1).*(840*(1+eta)*exp(xi*Yd(I,1)-(1+eta)*smat(I,1))./...
    (1+exp(xi*Yd(I,1)-(1+eta)*smat(I,1)).^2)).^(I-1));%did not square the exp term in denominator