Weighting Function
Use this feature to specify the function used to compute posterior probabilities from distances or to weight observations when computing k-nearest neighbor means.
Available options are described in the table below:
Option |
Description |
Gaussian |
Indicates the Gaussian kernel function as described in the SAS/STAT PROC DISCRIM documentation. |
Exponential |
Similar to Gaussian but uses distances inside the exponential function instead of squared distances. |
Reciprocal |
Indicates reciprocal distances. Note: In this case,1 is added to the distances before computing the reciprocal. |
Cauchy |
Uses reciprocal squared distances. Note: In this case,1 is added to the distances before computing the reciprocal. |
Uniform |
A uniform kernel creates equal weights of 1. |
For continuous responses with nonuniform kernels, a scaling factor for the distances is estimated by minimizing root mean square error.
To Specify the Desired Weighting Function:
8 | Select the desired function by clicking within the appropriate radio button. |