From stuct to array
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Hello everyone,
I have created a struct S as:
syms x1 x2 nnX1 nnX2
p1Space = linspace(0,50,10);
p2Space = linspace(0,25,10);
for i=1:10
S(i) = vpasolve(x1^2 + x2^2 - p1Space(i) == 0, x1*x2 - p2Space(i) == 0, [x1 x2]);
end
and I get an error when I perfom the following for loop in order to store specific elements into two arrays (XX1 and XX2):
for k = 1:10
XX1(k) = S(k).x1(2,1);
XX2(k) = S(k).x2(2,l);
end
When I type in the command window for example S(4).x1(2,1), the number appears on the screen, but inside the for-loop, this doesn't work. Any ideas why is this happening and how can I store these spesific values into the XX1 and XX2 arrays?
Thank you
1 个评论
Ameer Hamza
2020-3-18
You are getting this error because S(1).x1 does not have two elements. Similar is the case for S(1).x2. All the other elements of S have two elements, therefore S(4).x1(2,1) in the command window. Try S(1).x1(2,1) in the command window.
采纳的回答
As stated in the documentation, the size of the vpasolve output corresponds to the number of the solutions. On the first iteration, there is only 1 solution which can be seen here,
S(1)
ans =
struct with fields:
x1: [1×1 sym]
x2: [1×1 sym]
On the first iteration of the k-loop (k=1), you're getting the error because you're trying to get the 2nd row of x1 and x2 but they only have 1 row.
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