fl. Baghdad, last half of 9th c.; his best-known work, a commentary on the Almagest of Ptolemy, is no longer extant. He is also credited with the composition of 2 zījes (Ibn al-Qifṭī says the longer was based on the Sindhind, the shorter was presumably based upon the Almagest). 3 shorter, more specialized treatises survive: (1) on the spherical astrolabe; (2) on finding the qibla direction and (3) on constructing hour lines in a hemispherical sundial.  Ibn Yūnus (d. ca. 1009 in his own zīj, criticized some elements of al-Nayrīzī’s astronomical work while praising him as a renowned mathematician. [BEA, DeYoung]; GAS V.283-5, VI.191-2, VII.156