The answers are right, but not in a very useful form. You'll find that a and b are given in terms of the symbol So for example, if you try something similar to the Note that the symbolic toolbox doesn't automatically know the values of variables you've You can quote the expression as a string ( int('1/(1+x^2)'), orĭefine x to be a symbol as in the following Matlab's unhappy that x doesn't have a value. Matlab will say ' ? Undefined function or variable 'x'' because If for instance you haven't made x a symbol and you try People have is with how Matlab and the symbolic toolbox interact. Here f will automatically be a symbolic object so you can do diff(f) To evaluate a symbolic object for a particular value of a variable, The symbol name matches the symbol's value it's easier to use the equivalent ' syms x'. in future x will be treated as a symbol entity). The command x=sym('x') creates a symbolic object called x which has the corresponding string representation x (i.e. To convert a symbolic object into a number use double - e.g. The following, for example, produces the result 5/6 Only digits, arithmetic operations will be different to those in Objects are essentially strings, but even if those strings contain Things of this type are created using the sym and With the Symbolic Math Toolbox comes a new matlab datatype - symbolic To make the most of the Symbolic Toolbox you need to be aware ofĪ few concepts, in particular symbolic objects sym ForĬommon operations it's easy to use - e.g. Integrating, differentiating, etc) and also has some solving routines. Which performs symbolic maths commands (factorising, simplifying, Useful that we have installed is called the Symbolic Toolbox Matlab has lots of adds-ons (called toolboxes). Information look at the References Introduction Learning to use the Symbolic Toolbox might save you hours of time. However, I'm not aware of such a capability in MATLAB using the symbolic toolbox.This little document hopes to convince you that spending a few minutes Now coming to what you wanted to do, it is possible in Mathematica to hold certain expressions unevaluated and massage it to get it in the final output form that you want. The definition for the above function is syms f x a b = The closest equivalent of this in MATLAB is called an anonymous function. For e.g., the pure function definition of a derivative w.r.t.

$matlab symbolic toolbox declare functions$

With pure functions, the definition is independent of the actual function and if you chuck in any argument, it should evaluate it. Mathematica behaves exactly the same: MATLAB: syms f x

When you initialize f to be a symbolic variable, there is no definition associated with f and hence a derivative w.r.t x should return 0 and a derivative w.r.t. This is not an abnormal behaviour, rather the expected one. This doesn't work, because MATLAB evaluates diff(f,x)=diff(f,y)=0 (it doesn't know if it is a function).

Matlab symbolic toolbox declare functions