Setting the Domain
For gridded and station data, a domain can be specified so that the analysis may be restricted only to a subset of the grids or stations. You will be prompted for the domain automatically after opening the file, but the domain can be subsequently reset using the Edit ~ X Data Domain or Edit ~ Y Data Domain menu items from the Input Window. The domain is set by specifying the northern, southern, western, and eastern limits. Latitudes must be represented as between 90 and -90, with negative values indicating latitudes in the southern hemisphere. Longitudes must be represented as values between -180 and +360, with negative values indicating longitudes in the western hemisphere. The program will check that the domain limits are sufficiently wide to allow for a minimum number of gridpoints or stations. The total number of gridpoints or stations within the domain will be indicated on the CPT Window, but this number only indicates the total number available, and so includes grids that will be treated as missing. The total number of gridpoints or stations actually used is only indicated once a Cross-validated or Retroactive analysis has been performed.