while loop for changing vairable

2021 2 23
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更新时间：2021 2 24
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I was curious if I could use a "while" loop to change a value inside a matrix to create a series of matrices. I created an array for theta which is 1x37. I was thinking maybe creating a while loop that could take one index at a time and produce a new matrix. Any help is appreciated, thank you.
theta = [-90:5:90]
m = sind(theta);
n = cosd(theta);

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Rik
Rik 2021-2-23
This is an example of the XY problem. You should not presume a while loop is the solution without a clear description of the problem. You haven't described what you want to do with sufficient detail for someone to be able to give an answer.
andrew krugle
andrew krugle 2021-2-24
Sorry for being unclear, my code is below, what I want to do is create an array of values for theta, from 90 to -90 and would like to plug them into my matrix with my variables m and n which are the function of changing theta. So in the end I would have created 37 new 6x6 matrices.
theta = [-90:5:90]
m = sind(theta);
n = cosd(theta);
T = [m^2 n^2 0 0 0 2*m*n;
n^2 m^2 0 0 0 -2*m*n;
0 0 1 0 0 0;
0 0 0 m -n 0;
0 0 0 n m 0;
-m*n m*n 0 0 0 m^2-n^2]

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Walter Roberson
Walter Roberson 2021-2-24

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theta = [-90:5:90]
M = sind(theta);
N = cosd(theta);
T = arrayfun(@(m,n)[m^2 n^2 0 0 0 2*m*n;
n^2 m^2 0 0 0 -2*m*n;
0 0 1 0 0 0;
0 0 0 m -n 0;
0 0 0 n m 0;
-m*n m*n 0 0 0 m^2-n^2], M, N, 'uniform', 0);

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andrew krugle
andrew krugle 2021-2-24
Walter thank you very much!! Exactly what I needed. I saw that it created T with 37 6x6 matrices. Out of curiousity since I've never done matrices within an array and pulling values out, I saw that it created T{1,2},T{1,2} T{1,3}...T{1,37}. If I wanted to pull the first column out of T{1,2} could I create a new vairable such as
C1 = T{1,2}(:,2)
Walter Roberson
Walter Roberson 2021-2-24
C1 = T{1,2}(:,1)
for first column ;-)
col1 = celfun(@(C) C(:,1), T, 'uniform', 0)
to get all of the column 1. You could then proceed to
col1mat = horzcat(col1{:});
to get a 6 x 37 matrix of column 1's
andrew krugle
andrew krugle 2021-2-24
You're amazing, Thank you so much

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