Graphics are great for exploring data, but how can they be used for looking at the large datasets that are commonplace today? This book shows how to look at ways of visualizing large datasets, whether large in numbers of cases or large in numbers of variables or large in both. Data visualization is useful for data cleaning, exploring data, identifying trends and clusters, spotting local patterns, evaluating modeling output, and presenting results. It is essential for exploratory data analysis and data mining. Data analysts, statisticians, computer scientists - indeed anyone who has to explore a large dataset of their own - should benefit from reading this book.