Nilakantha Somayaji

| death_place = | resting_place_coordinates = | nationality = | citizenship = | other_names = Kelallur Comatiri | known_for = Authorship of Tantrasamgraha | education = | alma_mater = | employer = | notable works = Golasara, Candrachayaganita, Aryabhatiya-bhashya, Tantrasamgraha | occupation = Astronomer-mathematician | years_active = | title = Somayaji | boards = | spouse = Arya | partner = | children = Rama, Dakshinamurti | parents = Jatavedan (father) | relations = }}

Keļallur Nīlakaṇṭha Somayāji (14 June 1444 – 1544), also referred to as Keļallur Comatiri, was a mathematician and astronomer of the Kerala school of astronomy and mathematics. One of his most influential works was the comprehensive astronomical treatise ''Tantrasamgraha'' completed in 1501. He had also composed an elaborate commentary on Aryabhatiya called the ''Aryabhatiya Bhasya''. In this Bhasya, Nilakantha had discussed infinite series expansions of trigonometric functions and problems of algebra and spherical geometry. ''Grahapariksakrama'' is a manual on making observations in astronomy based on instruments of the time. Provided by Wikipedia