---
layout: doc
title: general / angle
---
# angle

### NAME

    angle() - return the angle between two numeric vectors

### SYNOPSIS

    float angle( int array | float array a, int array | float array b );

### DESCRIPTION

    Returns the angle, in radians, between vectors a and b.  Both vectors
    must have the same number of elements, and each element must be an int
    or float.

    The driver calculates:

        acos(dotprod(a, b) / (norm(a) * norm(b)))

    If the vectors have different sizes, or if either vector contains a
    non-numeric element, an error is raised.  The vectors should be nonzero,
    since the calculation divides by both vector norms.

### SEE ALSO

    dotprod(3), norm(3), distance(3), acos(3)
