SLA_DSEPV - Angle Between 2 Vectors   

ACTION:

Angle between two vectors (double precision).

CALL:

D = sla_DSEPV (V1, V2)

GIVEN:

V1 first vector

V2 D(3) second vector

RETURNED:

sla_DSEPV angle between V1 and V2 in radians

NOTES:

1.

There is no requirement for either vector to be of unit length.

2.

If either vector is null, zero is returned.

3.

The result is always positive.