## CCA Modes

When performing CCA, in addition to specifying the numbers of modes for the X and Y variables, it is also necessary to define the number of CCA modes. The CCA mode fields work in an identical manner to the X and Y mode fields: the minimum and maximum numbers of modes should be set, and if they differ CPT will optimise the number. A prompt for the numbers of CCA modes will appear automatically after the X and Y modes options are specified if both the X and Y input files are now opened. However, this prompt will not appear if the number of CCA modes is constrained to be one (see comments below regarding restrictions on the numbers of modes). The numbers of CCA mode can be reset under the Options menu item. Note that changing the number of X or Y modes will require CPT to reset if results have been calculated.

There are a few restrictions on the number of CCA modes:

- the minimum number of CCA modes cannot exceed the minimum number of X or Y modes;
- the maximum number of CCA modes cannot exceed the maximum number of X or Y modes.