linear transformations

The first lecture of Gilbert Strang's MIT 18.06 Linear Algebra course, covering the geometry of linear equations. It opens a full 35-lecture university course.

The introductory lecture of Stephen Boyd's Stanford Convex Optimization I course (EE 364A). It outlines convex sets, functions and problems, and the course's coverage of least-squares, linear and semidefinite programming, duality and interior-point methods.

Jon Bentley walks through three implementations of Hoare's Quicksort, from a dozen-line C function to a series of systematic code transformations that make the program ever simpler and more powerful. It is a Google Tech Talk on code elegance and program derivation.