Interactively visualize Box-Cox transformations

Description

Explore the Box-Cox family of distributions by plotting data transformed and untransformed and interactively choose values for lambda.

Usage

vis.boxcox(lambda = sample(c(-1, -0.5, 0, 1/3, 1/2, 1, 2), 1))

vis.boxcoxu(lambda = sample(c(-1, -0.5, 0, 1/3, 1/2, 1, 2), 1))

Arguments

Details

These functions will generate a sample of data and plot the untrasformed data (left panels) and the transformed data (right panels). Initially the value of lambda is 1 and the 2 sets of plots will be identical.

You then adjust the transformation parameter lambda to see how the right panels change.

The function vis.boxcox shows the effect of transforming the y-variable in a simple linear regression.

The function vis.boxcoxu shows a single variable compared to the normal distribution.

Value

These functions are run for the side effects. There is no meaningful return value.

Author(s)

Greg Snow greg.snow@intermountainmail.org

References

GEP Box; DR Cox. An Analysis of Transformations. Journal of the Royal Statitical Society. Series B, Vol. 26, No. 2 (1964) 211-252

See Also

bct, boxcox in package MASS

Examples

## Not run: 
vis.boxcoxu()
vis.boxcox()
## End(Not run)