| E02CAF | Least squares surface fit by polynomials, data on lines parallel to one independent coordinate axis |
| E02DAF | Least squares surface fit, bicubic splines |
| E02DCF | Least squares surface fit by bicubic splines with automatic knot placement, data on rectangular grid |
| E02DDF | Least squares surface fit by bicubic splines with automatic knot placement, scattered data |