Now that the program can build trees, the next step is to read sequence data from a Nexus-formatted file and store the data patterns compactly.
| Step | Title | Description |
| Step 9.1 | Create the DataType and GeneticCode classes | Create two classes needed for storing command line arguments that define partition subsets. |
| Step 9.2 | Create the Partition class | Create the class that interprets user specification and storage of partition information. |
| Step 9.3 | Create the Data class | Create a class that can read sequence data files and store the data compactly. |
| Step 9.4 | Test Reading and Storing Data | Test the Data class by reading and storing data from a nexus-formatted data file. |