Subs Command for Multivariable Function (2024)

For some reason I keep getting an error in this line of code.

i dont think there shd be s dot after e^(-2*x/3)

Dot between the e and the ^ is needed if x might be non-scalar. Dot between the ) and the *tan is needed if x and y might both be non-scalar.

That said, exp() is recommended instead of e^

As a matter of style: I recommend that .* be used in any case involving variables unless you deliberately mean matrix multiplication (inner product). I would suggest * with scalars only for very simple constant multiples, such as 3*x -- but not, for example, x*y even if you know that x and y are both scalars. Using .* explicitly saves thinking by other people reading the code about whether you really meant matrix multiplication and saves programmers reading your code tracing back to prove that in every possible code path to that point, that x and y are guaranteed to be scalars.

The question I am trying to solve is to evaluate that function at x & y are equal to the listed values using the subs command and by conversion into a matlab function.

This case the code above should work. Though, you can do it easier and with faster computation avoiding symbolic computations as, e.g. (there are many ways to do it)

and call it as

The error in your code is because Matlab is unaware what the variable "e" is. If you mean the exponent function, use "exp" instead, as in the code above. If you actually defined "e" somewhere before, the error can be with nonscalar values; if you mean the element-wise operation, use ".^" instead of "^" analogous to ".*" in the following part.