Checking For Incidence of A Line On A Point
Given line L and point P in a projective plane, and both expressed in homogeneous coordinates, then P⊂L if and only if the dual of the line is perpendicular to the point (so that their dot product is zero); that is, if
where g is the duality mapping.
An equivalent way of checking for this same incidence is to see whether
is true.
Read more about this topic: Incidence (geometry)
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