# Spatial

## distanceBetween(agentA, agentB, distanceFunction)

This function returns the distance between two agents, using a specific distance function. You can pass the current agent's `state` as one of the agents. The different distance functions are:

`function behavior(state, context) {    const { neighborA, neighborB } = context.neighbors();        // Find the closest of 2 neighbors to you    const distanceToA = hash_stdlib.distanceBetween(state, neighborA);    const distanceToB = hash_stdlib.distanceBetween(state, neighborB);    const closest = distanceToB > distanceToA ? "A" : "B";        state.set("closest", closest);        // Check if neighbors are closer to each other than to you    const neighborDistance = hash_stdlib.distanceBetween(neighborA, neighborB);    const selfDistance = closest === "A" ? distanceToA : distanceToB;        state.set("closer_to_neighbors", selfDistance < neighborDistance);}`

## normalizeVector(vec)

This function returns the unit vector of the `vec` array. You can use it to normalize an agent's direction vector after it's modified.

`function behavior(state, context) {    const dir = state.get("direction");        // Modify the direction by adding a vector [1, 2, 0]    dir[0] += 1;    dir[1] += 2;        // Turn it back into a unit vector    state.set("direction", hash_stdlib.normalizeVector(dir));}`

## randomPosition(topology, z_plane)

This function returns a random integer position within the bounds of the `topology`. The Topology should be user-defined in globals.json (see Topology). By default`z_plane` is `false` and the returned position is in a 2D plane. Pass true to return a position in 3D space.

`function behavior(state, context) {    // Move to a random position    const topology = context.globals().topology;    const new_pos = hash_stdlib.randomPosition(topology);        state.set("position", new_pos);}`