### 4.4 Predicates for Numeric Objects

— Built-in Function: isnumeric (x)

> Return nonzero if x is a numeric object.

— Built-in Function: isreal (x)

> Return true if x is a real-valued numeric object.

— Built-in Function: iscomplex (x)

> Return true if x is a complex-valued numeric object.

— Built-in Function: ismatrix (a)

> Return 1 if a is a matrix. Otherwise, return 0.

— Function File: isvector (a)

> Return 1 if a is a vector. Otherwise, return 0.

— Function File: isscalar (a)

> Return 1 if a is a scalar. Otherwise, return 0.

— Function File: issquare (x)

> If x is a square matrix, then return the dimension of x. Otherwise, return 0.

— Function File: issymmetric (x, tol)

> If x is symmetric within the tolerance specified by tol, then return the dimension of x. Otherwise, return 0. If tol is omitted, use a tolerance equal to the machine precision.

— Built-in Functio: isbool (x)

> Return true if x is a boolean object.