#### 8.3.10 Vector properties

The following functions are defined for real and complex vectors. For complex vectors both the real and imaginary parts must satisfy the conditions.

Function: int gsl_vector_isnull (const gsl_vector * v)
Function: int gsl_vector_ispos (const gsl_vector * v)
Function: int gsl_vector_isneg (const gsl_vector * v)
Function: int gsl_vector_isnonneg (const gsl_vector * v)

  These functions return 1 if all the elements of the vector v are zero, strictly positive, strictly negative, or non-negative respectively, and 0 otherwise.

Function: int gsl_vector_equal (const gsl_vector * u, const gsl_vector * v)

  This function returns 1 if the vectors u and v are equal (by comparison of element values) and 0 otherwise.