Created Issue: high collisions in GetHashCode [9176]

Fraserc — Sat, 18 Feb 2012 11:15:34 GMT

I really like this class but the implementation of GetHashCode produces high collisions.

public override int GetHashCode()
{
return (latitude+longitude).GetHashCode();
}

Indeed with the current code any two coordinates with the same latitudinal longitudinal sum with cause collisions. So, these all have the same hash.

Coordinate(-1,6)
Coordinate(0,5)
Coordinate(1,4)
Coordinate(2,3)
Coordinate(3,2)
Coordinate(4,1)
Coordinate(5,0)
Coordinate(6,-1)

You get the idea....

Anyhow, something like the following will resolve the issue.

public override int GetHashCode()
{
int hash = 13;
hash = (hash * 7) + latitude.GetHashCode();
hash = (hash * 7) + longitude.GethashCode();
return hash;
}

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Created Issue: high collisions in GetHashCode [9176]