Philipp K. Janert provides consulting services for data analysis and mathematical modeling, drawing on his previous careers as physicist and software engineer.

He is the author of Data Analysis with Open Source Tools (O'Reilly Media) and Gnuplot in Action: Understanding Data with Graphs (Manning Publications) and has written for the O'Reilly Network, IBM developerWorks, and IEEE Software. He holds a Ph.D. in theoretical physics from the University of Washington.

Visit his company website at principal-value.com.