Similarity patterns in language

Dotplot is a technique for visualizing patterns of string matches in millions of lines of text and code. Patterns may be explored interactively or detected automatically. Applications include text analysis (author identification, plagiarism detection, translation alignment, etc.), software engineering (module and version identification, subroutine categorization, redundant code identification, etc.), and information retrieval (identification of similar records in results of queries). Patterns are interpreted though a visual language. Squares identify unordered matches (documents with lots of matching words or subroutines with lots of matching symbols), while diagonals identify ordered matches (copies, versions, and translations). Patterns of squares and diagonals have more complex interpretations that identify subtler relationships