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Is there any way to get numerical result from symbolic function?

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Hi,
I have a smybolic function created by syms command and at the next steps in my code, i should get numerical output by using this function. To do this operation, i copy the symbolic function from workspace and paste my editor. This is too long method and easy to make mistake. So, i have to use symbolic function directly.
What kind of methods can i use for this operation? Do you have any example about this?
Thx!

Accepted Answer

Ameer Hamza
Ameer Hamza on 30 Oct 2020
Edited: Ameer Hamza on 30 Oct 2020
If you have a symbolic function, you can directly evaluate by giving the input. For example
syms x
y(x) = x.^2 + 2*x + 3; % symbolic function
Then run the following
>> y(3)
ans =
18
>> y(100)
ans =
10203
If you want output in floating-point format, you can use double()
double(y(100))
If you have a symbolic expression, then you can use subs()
syms x
y = x.^2 + 2*x + 3; % symbolic expression
and then run
>> subs(y, x, 3)
ans =
18
>> subs(y, x, 100)
ans =
10203

More Answers (2)

KSSV
KSSV on 30 Oct 2020
You can substitute a variable value in the syms using subs and then use double, vpasolve to convert into numerica array.
Read about subs, double.

Walter Roberson
Walter Roberson on 30 Oct 2020
Use matlabFunction to convert the expression into a numeric function.

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