How can i assign sybolic values to ymbolic variables in an symbolic matrix?

Question

Darko Kulic 2021-12-2

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1601420-how-can-i-assign-sybolic-values-to-ymbolic-variables-in-an-symbolic-matrix

评论： Darko Kulic 2021-12-2

Hi folks,

I actually want to write a function for any kind of rotational robot. The function should give back the Translation Matrixes and the Jacobi Matrix. To do that I need to differentiate my final T Matrix.

So my code shoudl do this:

Pseudo Code:

n = 10
c_array = create_symbolic_array('c',[1 n]) %% c1 c2 ... cn
t_array = create_symbolic_array('th', [1 n]) %% th1 th2 ... thn
%% Loop to assign c1 = cos(th1)
loop(1:1:n) 
    c_array(1,n) = cos(th(1,n))     
%result should be 
c1 = cos(th1)
c2 = cos(th2)
.
.
.
cn = cos(thn)

cn should be an symbolic type with the value assigned cos(th1), if it isnt an array its fine, but i need c1 c2 c3 and so with the cos(thn) assigned,

I tried a lot of things.

Here one of my examples coded in MATLAB

% test data
a = [100 100 100 100]
alpha = [90 90 90 90]
d = [0 10 10 10]
theta1=[0 0 0 0]
sz_a = size(a,2);
sz_alpha = size(alpha,2);
sz_d = size(d,2);
sz_th = size(theta1,2)
theta = sym('th', [1,sz_th])
cosinusse = sym('c', [1,sz_th])
sinussse = sym("s", [1,sz_th])
T0_n = zeros(sz_th)
Ti_j= zeros(sz_th)
%symbolic array
syms('c',[1 4])
%% Of course this needs to be looped, but sprintf do not assign it is only printing
sprintf("%s=%d", strcat('c', num2str(1)), cos(theta1(1,1)))
% also I tried
for i = 1:sz_th
    c(1,i) = cos(theta(1,i))
    
end
for i = 1:sz_th
    
    sprintf("%s=%d", strcat('c', num2str(i)), cos(theta1(1,i)))
    
end