414: Validation - Scatter Plots

The Scatter Plots option shows a graph of the forecast residuals (differences between the forecasts and the observations), as well as a scatter plot of the observations against the forecasts. The scatter plot includes horizontal and vertical divisions that indicate the three categories. In both cases the divisions are defined by the terciles of the observations using all the cases. A least-squares linear regression line is shown on the scatter plot, but only over the range of the forecasts.

The y-axis limits on the plots can be set by right-clicking on the image and then selecting the Customise option. The x-axis limits on the scatter plot are automatically set to be the same as for the y-axis. When resetting the axis limits, the maximum and minimum values on the y-axis are indicated and can be reset. Resetting these axis limits will in turn automatically reset the tick-mark interval and number of tick marks. Greater flexibility for setting the tick marks is planned for future releases. Further options for customising the graphs, including adjusting the size of the fonts, and the size of the images, are available from Options ~ Graphics .

The graphs can be saved as graphics files by right-clicking anywhere in the child window and selecting Export from the pop-up menu. A default name is given to the graphics file, but this name can be changed using the browse button. The image quality for all the graphics formats can be improved by increasing the size of the image (see Options ~ Graphics ~ Graph Scaling ).

Further details are available under Viewing results .