How to append in a while loop?

14 次查看（过去 30 天）
Maram
Maram 2022-12-5
评论： Maram 2022-12-5
Hello,
I am trying to run a loop to get the values of lambda in an array, number of rows is unknown, which to be determined when a certian limit is met. For each n there supposed to be 2 values each for W ,c ,lambda ,phi
The goal is to keep lambda values and ph values as they will be used in other steps. I was trying to append
When all added at the end it should be like,
when n =1 , we get:
lambda 1
lambda 2
n=2,
lambda 3
lambda 4
.
.
and so on.
The code I wrote seem to have some issue with the indices, I am fairly new to matlab so I am not sure how to the fix should be. Any help is appreciated.
limit =0.01;
repeat= true;
Ad= (linspace(-2.5,2.5,26))';
b=2;
n=1;
while repeat==true
syms z
W(n)= vpasolve(1/b -z*tan(z*a), z, [(n-1)*(pi/a) (n-(1/2))*(pi/a)]);
c(n)= 1/((a+(sin(W(n)*a)/2*W(n)))^0.5);
lambda(n)= (2*b)/(1+((W(n)^2)*(b^2)));
ph(n)= c(n)*cos(W(n)*Ad(n));
W(n)= vpasolve(((1/b *tan(z*a)) + z), z, [(n-(1/2))*(pi/a) (n)*(pi/a)]);
c(n)= 1/((a-(sin(W(n)*a)/2*W(n)))^0.5);
lambda=[(2*b)/(1+((W(n)^2)*(b^2))),n];
ph= [c(n)*sin(W(n)*Ad(n)),n];
if lambda(n)/lambda(1) < 0.01
repeat= false;
end
n=n+1;
end
I get an error for the if line ,
Index exceeds the number of array elements (2).

请先登录，再回答此问题。

采纳的回答

David Hill
David Hill 2022-12-5
Where is 'a' assigned? Lots of guessing here, but this might help you.
limit =0.01;
Ad= (linspace(-2.5,2.5,26))';
b=2;a=1;
n=1;
while 1
syms z
W(n,1)= double(vpasolve(1/b -z*tan(z*a), z, [(n-1)*(pi/a) (n-(1/2))*(pi/a)]));
c(n,1)= 1/((a+(sin(W(n,1)*a)/2*W(n,1)))^0.5);
lambda(n,1)= (2*b)/(1+((W(n,1)^2)*(b^2)));
ph(n,1)= c(n,1)*cos(W(n,1)*Ad(n));
W(n,2)= double(vpasolve(((1/b *tan(z*a)) + z), z, [(n-(1/2))*(pi/a) (n)*(pi/a)]));
c(n,2)= 1/((a-(sin(W(n,2)*a)/2*W(n,2)))^0.5);
lambda(n,2)=(2*b)/(1+((W(n,2)^2)*(b^2)));
ph(n,2)= c(n,2)*sin(W(n,2)*Ad(n));
if lambda(n,1)/lambda(1,1) < 0.01
break;
end
n=n+1;
end
  1 个评论
Maram
Maram 2022-12-5
Sorry I forgot to mention, a=2.5
It's extremely helpful tho, thank you so much for your quick reply!

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

产品


版本

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by