This document discusses using the Matlab Profiler GUI tool and provides 4 examples of ways to speed up Matlab code: 1) Avoiding loops by vectorizing operations, 2) Avoiding growing variables which require copying to new memory locations, 3) Reducing function call overhead by passing arguments rather than defining new functions, and 4) Using sparse matrices instead of full matrices when possible to reduce memory usage and computation time. The examples demonstrate profiling code with the Matlab Profiler and provide specific cases of optimizing code for improved speed and efficiency.