Creating an array of dependent symbolic variable
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Hi,
I need to create 'N' equations based on user input 'N' which is a natural number.
Each equation is supposed to have a variable A which is a dependent on x. This 'A' term is different for each equation. Equation1 will have A1, equation2 will have A2 and so on.
I am creating this term using the expresion below.
A = sym('A', [1 N]);
This gives me symbolic variables A1, A2, A3... AN. But the problem is these terms are just symbolic variables and not dependent on x. So if I differentiate the equation with respect to x, these terms dissappear. If I use A(x) to create the variable (like a normal dependent variable), it returns a 1x1 symbolic function instead of 1xN symbolic variables.
A(x) = sym('A', [1 N]);
The above equation creates 1xN symbolic variables but the output is of type 1x1 symbolic function. Is there a way to isolate each term from this function or is there any other way to create a dependent variable array.
Thanks
采纳的回答
madhan ravi
2020-10-13
编辑：madhan ravi
2020-10-13
A(x) = str2sym(regexprep(char(A), '(\_?\d)+', '$0(x)'))
3 个评论
Abinav
2020-10-13
madhan ravi
2020-10-13
编辑：madhan ravi
2020-10-13
A(x) = str2sym("A" +(1:N)+"(x)")
Wanted = formula(A)
Wanted(2)
[Too many edits in mobile is so painful ;)]
Abinav
2020-10-14
更多回答（1 个）
Steven Lord
2020-10-13
syms A [1 2]
eq1 = A(1)+2*A(2) == 42
eq2 = 3*A(1)-4*A(2) == 99
S = solve(eq1, eq2)
A1 = S.A1
A2 = S.A2
subs(eq1)
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