## SYMVAR Find Symbolic Variables in an Expression

Section: Function Related Functions

### Usage

Finds the symbolic variables in an expression. The syntax for its use issyms = 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]