Lope de Vega dedicated to him a celebrated play entitled Las Almenas de Toro (1619), and when Castro's Comedias were published in 1618-1621 he dedicated the first volume to Lope de Vega's daughter.
In 1794 Vega published his Thesaurus logarithmorum completus, a folio volume containing a reprint of the logarithms of numbers from Vlacq's Arithmetica logarithmica of 1628, and Trigonometria artificialis of 1633.
Vega devoted great attention to the detection and correction of the errors in Vlacq's work of 1628.
Vega's Thesaurus has been reproduced photographically by the Italian government.