Time Series Analysis - Active Work Area
All variables (series) and their transformations that are currently available for analysis are stored in the active work area and listed in the edit fields at the top of the dialog box. When you select new variables, the active work area will first be cleared, and then the selected variables will be read into the active work area (after all "holes" with missing data have been "patched"). The following information applies to the active work area.
Element Name | Description |
---|---|
Highlighted variable | All subsequent analyses will be performed on the highlighted variable. For example, when you perform a transformation, the currently highlighted variable will be transformed, and a new (transformed) variable will be appended to the active work area. To highlight a variable, simply click on it in any of the edit fields. |
Naming conventions | When a new (e.g., transformed) variable is appended to the active work area, it is assigned 1) the same short variable name as the original variable (that was transformed), and 2) a new long variable name that consists of the old long variable name (as much of it as will fit) and a brief description of the respective transformation that was performed. In this manner, as you perform successive transformations or analyses (e.g., successively difference a series), an automatic log of transformations will be maintained in the long variable names. For example: |
- Editing variable names
- Double-click in the column labeled Variable or Long variable (series) name to edit the short or long variable name for the series in the active work area. Note that the short and long names will only be changed in the active work area, not in the file (use the respective data spreadsheet operations to permanently change those names).
- Number of backups per variable (series)
- All dialog boxes that contain the edit fields for highlighting a variable (series) for analysis also contain a field for specifying the desired Number of backups per variable (series). After a transformation (or other analysis) is performed on a series, the resulting transformed series (or residuals, forecasts, etc. in ARIMA) will be appended to the active work area, and the values of the series prior to the transformation will be maintained as a backup. The number of such backups that will be maintained in the active work area is controlled by the Number of backups per variable (series) parameter. Thus, for example, if this parameter is set to 3 (default), and you have just performed the fourth transformation of an original variable, then the series with the data after the first transformation will be dropped from the active work area, and replaced by the new (fourth) transformation. Thus, successive transformations will be appended to the active work area until there are as many backups as specified in this parameter; at that point the respective "oldest" transformation will be replaced by the new one. Up to 99 backups can be kept of a single original variable.
- Locking variables (series)
- The first column of the edit fields carries the header Lock. When you double-click in that column for a transformed variable, that variable will be locked in the active work area (or unlocked, if it was previously locked). An L will be displayed in that column to indicate that the variable is now locked. Locked variables will not be replaced as successive transformations exceed the current maximum number of backups. Note that original (untransformed) variables are always locked, and they cannot be unlocked.
- Deleting variables (series) from the current work area
- To delete a transformed variable from the active work area, click the Delete highlighted variable button. Original (untransformed) variables cannot be deleted.
- Saving variables (series) in the current work area
- Click the Save variables button to save the variables (series) in the active work area into a standard STATISTICA data file. You can save all variables or only selected variables.
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