Ibn al-Kammād's \textit{Muqtabis} zij and the astronomical tradition of Indian origin in the Iberian Peninsula (Q889612)

Indian astronomical computations were based on the sine function whereas Ptolemy uses the chord, \(\mathrm{chord}(2a)=2\sin a\). The use of the sine function in the computation of astronomical tables therefore is a trustworthy indication of Indian influence (brought to Arabic astronomy by al-Khwarizmi). The authors give a careful review of the astronomical tables contained in the zij \textit{al-Muqtabis} of the 12th-century astronomer of Cordoba Ibn al-Kammād, of which two versions, Latin and Hebrew, are preserved, each in a single manuscript. The investigation is based on the publication of this zij by the authors [ibid. 48, No. 1, 1--41 (1994; Zbl 1350.01005)]. In a lengthy introduction, the authors follow the traces of Indian influence from al-Khwarizmi through Ibn al-Kammād down to 1400 and the Latin tradition. This is followed by an analysis of 50 tables, astronomical and astrological, with detailed analysis for those tables whose data need mathematical elucidation, such as for the equation of the sun. The paper is complemented by a very detailed bibliography of 4 1/2 pages.