In the late 19th century, Karl Weierstrass invented a fractal-like function that was decried as nothing less than a “deplorable evil.” In time, it would transform the foundations of mathematics.

How to turn the complex mathematics of vector calculus into simple pictures Feynman diagrams revolutionized particle physics. Now mathematicians want to do the same for vector calculus.

Many statistical operations benefit from differential calculus. Examples include optimization of likelihood functions and calculation of information matrices. For multiparameter models differential ...