“For anyone curious about the math underlying modern computational science, this book offers just about everything you'll need. It's clear, comprehensive, and charming.”- Steven Strogatz, Cornell University“I have been teaching from Humpherys' and Jarvis’ notes for this book since 2013, and I love it. This book should be a required reference for mathematicians, statisticians, economists, and data scientists.""- Richard W. Evans, University of Chicago