 Although the gamma function can be calculated virtually as easily as any mathematically simpler function with a modern computer—even with a programmable pocket calculator—this was of course not always the case.Until the mid-20th century, mathematicians relied on hand-made tables; in the case of the gamma function, notably a table computed by Gauss in 1813 and one computed by Legendre in 1825.Tables of complex values of the gamma function, as well as hand-drawn graphs, were given in "Tables of Higher Functions" by Jahnke and , first published in Germany in 1909.