Discriminant & TableOfReal: To TableOfReal (mahalanobis)...

Calculate Mahalanobis distances for the selected TableOfReal with respect to one group in the selected Discriminant object.

## Settings

Group label
  defines which group mean to use for the distance calculation.
Pool covariance matrices
  when on, use a pooled covariance matrix instead of the group covariance matrix.

## Algorithm

See Covariance & TableOfReal: To TableOfReal (mahalanobis)....

## Example

Calculate the number of datapoints that are within the one-sigma elipses of two different groups, i.e. the number of data points that are in the overlapping area.

Suppose the group labels are ø and ʏ.

`pols50m = Create TableOfReal (Pols 1973): "no"
` `Formula: ~ log10 (self)
` `discriminant = To Discriminant
` `selectObject: pols50m, discriminant
` `t1 = To TableOfReal (mahalanobis): "\o/", "no"
` `selectObject: pols50m, discriminant
` `t2 = To TableOfReal (mahalanobis): "\yc", "no"
`

Now we count when both the t1 and t2 values are smaller than 1 (sigma):

`Copy: "tr"
` `Formula: ~ object [t1] < 1 and object [t2] < 1
` `Extract rows where column: 1, "equal to", 1
` `no = Get number of rows"
`