How do I simplify the values of a function?

Hi! I want to calculate a function, lets say f(x), that for example, may have the definition f(x) = a*b + b*x, where "a" and "b" are known values in my workspace. I want MATLAB to simplify this function for me. For example, if a = 2 and b = 4, I would like to get f(x) = 8+4x. I know I can define this function as an anonymous function, but that doesn't simplify the function, it simply states it. How can I get the function in a simplified way?

Thanks in advance

Answer 1

[madhan ravi]

>> a

a =

     2

>> b

b =

     4

>> syms x
   f(x) = a*b + b*x
 
f(x) =
 
4*x + 8
 
>> 

[madhan ravi]

I think you maybe looking for subs() to substitute the values.

doc subs

[Guillem Campins]

That doesn't work for me, it complains that x is not defined.

[madhan ravi]

Check the edited code.

[Guillem Campins]

Great! Thanks very much

Answer 2

[Stephan]

Can be done with symbolic toolbox - matlabFunction returns an anonymous function the way you want:

syms x
% known constants
a = 2;
b = 4;
% equation as symbolic
eq = a*b + b*x;
% create function handle
fun = matlabFunction(eq)

result:

fun =

  function_handle with value:

    @(x)x.*4.0+8.0

[Guillem Campins]

Thanks very much!

[Stephan]

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