map.remove(key) If the map has an entry for the specified key string, removes the entry and returns true. Otherwise, this method does nothing and returns false.

map.keys() Returns an array of string keys for every entry in this map. The order of the returned keys is arbitrary.

map.has(key) Returns true if and only if this map has an entry for the specified key string. Note: the value may be null or undefined.

map.get(key) Returns the value for the specified key string. If the map does not have an entry for the specified key, returns undefined.

map.entries() Returns an array of key-value objects for each entry in this map. The order of the returned entries is arbitrary. Each entry’s key is a string, but the value has arbitrary type.

map.empty() Returns true if and only if this map has zero entries.

map.each(function) Calls the specified function for each entry in this map, passing the entry’s value and key as arguments, followed by the map itself. Returns undefined. The iteration order is arbitrary.

map.clear() Removes all entries from this map.

manyBody.theta([theta]) If theta is specified, sets the Barnes–Hut approximation criterion to the specified number and returns this force. If theta is not specified, returns the current value, which defaults to 0.9. To accelerate computation, this force implements the Barnes–Hut approximation which takes O(n log n) per application where n is the number of nodes. For each application, a quadtree stores the current node positions; then for each node, the combined force of all other nodes on th

manyBody.strength([strength]) If strength is specified, sets the strength accessor to the specified number or function, re-evaluates the strength accessor for each node, and returns this force. A positive value causes nodes to attract each other, similar to gravity, while a negative value causes nodes to repel each other, similar to electrostatic charge. If strength is not specified, returns the current strength accessor, which defaults to: function strength() { return -30; } The strength