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Selection of events located within a cone is implemented more accurately.
For each event cartesian coordinates (x,y,z) were computed from the celestial coordinates (ra,dec) and have been stored in the event table.
A bounding box of the intersection of the sphere by the cone is computed. If a pole is located in the cone a whole cap is kept.
Events located inside this box are selected. For each event in this subset the dot product between their direction and the axis of the cone is computed.
A query looks like :

select event_number, run_number, time, energy, quality, ra, decl from events
where (1198 <= ra and ra <= 2041 and 1980 <= decl and decl <= 2340) and
(x * 0.35355338 + y * -0.35355338 + z * 0.8660254 > 0.9961946980917455)

A typical result with MySQL is shown here.

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