SYMVAR Find Symbolic Variables in an Expression

Section: Function Related Functions

Usage

Finds the symbolic variables in an expression. The syntax for its use is 
  syms = symvar(expr)

where expr is a string containing an expression, such as 'x^2 + cos(t+alpha)'. The result is a cell array of strings containing the non-function identifiers in the expression. Because they are usually not used as identifiers in expressions, the strings 'pi','inf','nan','eps','i','j' are ignored.

Example

Here are some simple examples: 
--> symvar('x^2+sqrt(x)')  % sqrt is eliminated as a function

ans = 
 [x] 

--> symvar('pi+3')         % No identifiers here

ans = 
  Empty array 0 1
--> symvar('x + t*alpha')  % x, t and alpha

ans = 
 [alpha] 
 [t] 
 [x]