The Update menu item provides a means of updating the data in one file with more recent data in a second file. The Update option will prompt for the two files containing the data. The file details will show up both on the merge window and on the main CPT window, but should be ignored on the main window - the distinction between the X and the Z file is irrelevant, and these files will be closed once the merging is complete. CPT expects that the file with the earliest data will be opened as the primary file, but the update file does not necessarily have to start or end after the primary file. If there is any overlap in the two files, the data in the primary file will be replaced by the data in the update file.
When the data from both files have been read, the user will be prompted for a new file name for the updated data.
The Update option is only available if the X and Y files are both closed; in addition, it cannot be accessed from the CPT title screen.