Smooth Loess

The Smooth Loess option in the Table menu offers an effective nearest neighbor Loess type of smoothing. This procedure works equally well with scattered or gridded data. The Gridded Smoothing option is recommended primarily for data on a full or sparse grid.

Smoothing Adjustments

The Loess algorithm contains two adjustments.

The Order determines the model to be fitted for smoothing, 1=planar, 2=bivariate quadratic, 3=bivariate cubic. The higher the order of the model fitted, the better features within the data will be preserved. For example the amplitude of 3D peak type data will suffer some attenuation with a planar fit but may suffer no loss with the 3rd order model.

The Count determines the number of nearest neighbor data points used in fitting. This can vary from that value which assures one degree of freedom in the fitting up to the total number of data points. The higher the number of nearest neighbor points, the greater will be the degree of smoothing.

Statistics

The SSE (sum of squares due to error) and r2 (coefficient of variation) are reported for the overall fit. The coloring of the data points by SE (standard error) relies on the assignment of degree of freedom based upon the local fitting function. This may furnish some evidence of outliers or possibly data that have been adversely impacted by the smoothing.

Surface Rendering

The surface is rendered by the Renka I procedure. This is informational only within this option.

Graph Controls

This option offers the common TableCurve Studio graph controls:

·    3D Type

·    3D View

·    Scaling

·    Animate

·    Titles

·    Font

·    Colors

·    Points

·    Copy

·    Print

Add

 The Add button adds a Loess smoothing object to the currently selected XYZ data object in the TableCurve Studio explorer. A Loess smoothing operation can be added to any item containing XYZ data, including the smoothed objects themselves.

Update

 If a Loess smoothing item is currently selected and the main graph is clicked, the Update button will be enabled. This updates the smoothing with the current settings as well as updating all graph customizations.

MS Word/RTF Export

The Word button is used to save the current graph to either a MS Word file or a portable RTF (Rich Text Format) file. The graph is inserted into the file as a Windows metafile.

Preserving the Current Smoothing Settings

Exit with OK to update the smoothing settings. These values will be reflected the next time the procedure is entered. To discard the current settings, close the procedure with the Cancel button. Note that the Add or Update options must be invoked before closing the dialog in order for the smoothing to be added to the current notebook.