Gabriel Lamé1795–1870
Generalised ellipse
French mathematician whose generalised ellipse equation became the foundation of the superellipse and many smoothly squared forms.
One exponent carries a shape from diamond through circle to near-square. Sweep it across a grid, or nest the whole range inside a single frame.
Gabriel Lamé, 1818 · Piet Hein, 1959

The curve is |x/a|ⁿ + |y/b|ⁿ = 1. At n = 1 it is a diamond, at n = 2 an ellipse, and beyond n = 4 it approaches a rounded rectangle, the squircle used for app icons and Piet Hein's Sergels torg. Exponents are interpolated in log space so each step reads as an equal change. Aspect stretches a and b apart.
Behind the mathematics
Generalised ellipse
French mathematician whose generalised ellipse equation became the foundation of the superellipse and many smoothly squared forms.
Superellipse in design
Danish polymath who popularised the superellipse in design and architecture, showing how mathematics can soften the meeting of circle and rectangle.