`findSymType`

Finds the subexpressions of a given symbolic type.

Category: Symbolic Computations in MATLAB > Symbolic Variables, Expressions, Functions, and Preferences

Syntax

found = findSymType(S, type)

Returns every subexpression of S whose type is type.

Description

The whole expression tree is searched, not only the top level. With 'variable' the result lists the symbolic variables in use; with 'integer' it lists every integer constant, including exponents and coefficients; with a function name it lists each distinct call of that function.

Use symType to find out which type name applies to a given object.

Input arguments

S: Symbolic expression.
type: Type name as a string, such as 'variable', 'integer', 'rational' or a function name like 'sin'.

Output arguments

found: Symbolic row vector of the matching subexpressions, without repeats. Empty when nothing matches.

Example

Variables, integers and function calls

syms x
S = x^2 + 3*x + sin(x);
findSymType(S, 'variable')
findSymType(S, 'integer')
findSymType(S, 'sin')

Output

ans = x
ans = 
[2, 3]
ans = sin(x)

findSymType