Stellar mass fraction of NGC 3115 in four bins of age/metallicity pairs: young (age ≲ 12 Gyr), old (age > 12 Gyr), metal-rich ([Z/H] = 0.2 dex), and metal-poor ([Z/H] < 0.2 dex). For each panel, the age and metallicity bin limits are indicated in the top left corner, the mean stellar mass fraction in the top right corner, and the colour scheme by the colour bar at the top of its respective column. The old and metal-poor stellar population of NGC 3115 is mostly located in its spheroid component, whereas the young and metal-rich stars are mostly in the disc component.