PK_VECTOR_is_parallel

PK_ERROR_code_t     PK_VECTOR_is_parallel
(
--- received arguments ---
PK_VECTOR_t         v1,
PK_VECTOR_t         v2,

--- returned arguments ---
PK_LOGICAL_t *const is_parallel
)


This function tests whether the two vectors are parallel within the
current session angle precision. If they are, 'is_parallel' is set
to PK_LOGICAL_true, otherwise to PK_LOGICAL_false.


Specific Errors:
    PK_ERROR_zero_vector           vector is zero vector (MILD)


The two vectors 'v1','v2' are parallel if their cross product satisfies
the relation:
            | v1 X v2 | <= | v1 | * | v2 | * precision
where 'precision' is the current session angle precision.