Chapters: 1: Introduction 2: Simple example 3: Invocation 4: Finer Control 5: X-Y Plots 6: Contour Plots 7: Image Plots 8: Examples 9: Gri Commands 10: Programming 11: Environment 12: Emacs Mode 13: History 14: Installation 15: Gri Bugs 16: Test Suite 17: Gri in Press 18: Acknowledgments 19: License Indices: Concepts Commands Variables | ## 8.12: Handling Data Handling Headers: How to skip or read header lines Ignoring Columns: Ignoring columns that are not of interest Column Algebra: How to do algebra on columns Combining Columns: Combining columns from separate files Plotting Several Columns: Plotting several y-columns vs one x-column