Salt Lake City-based CORDA Technologies said yesterday that it has been issued a patent for its charting software tools. The company said that it received a patent for its a method for dynamically generating a textual description of online charts and graphs, enabling the visually impaired to have access to information contained within charts, graphs and maps generated with Corda's software tools. Corda develops graphing and charting software tools used for data visualization. The patent is No. 6,972,763 and named Troy Millett, Derrick Shadel, and Mardell Cheney as inventors.