`isSymType`

Tests the symbolic type of each element of an array.

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

Syntax

tf = isSymType(S, type)

Returns a logical array telling which elements of S are of type type.

Description

Only the object itself is classified, not its parts. isSymType(x + 1, 'variable') is false because the sum as a whole is an expression. Types form a hierarchy in which a more specific type also satisfies the general ones, so the integer 2 is of type 'integer' and also 'rational'.

For a symbolic array the test is applied to each element, which makes it handy for picking out the numeric entries of a mixed matrix.

Input arguments

S: Symbolic scalar or array.
type: Type name string, such as 'variable', 'integer', 'rational' or 'expression'.

Output arguments

tf: Logical array of the same size as S.

Example

Classifying the elements of a vector

syms x
v = [x, 2, x + 1, sym(1)/3];
isSymType(v, 'variable')
isSymType(v, 'integer')
isSymType(v, 'rational')

Output

ans = 1×4 logical array

   1   0   0   0
ans = 1×4 logical array

   0   1   0   0
ans = 1×4 logical array

   0   1   0   1

isSymType