# multicomp.reverse {HH}

### Description

Force all comparisons in a `"multicomp"`

object to have the same sign. If the contrast `"A-B"`

has a negative estimate, reverse it show the contrast `"B-A"`

with a positive estimate. If a contrast name does not include a minus sign `"-"`

and the contrast is reversed, then an informative message is printed.

### Usage

multicomp.reverse(y, estimate.sign = 1, ...)

### Arguments

- y
`"multicomp"`

object- estimate.sign
- If
`estimate.sign==1`

, reverse the negatives. If`estimate.sign==-1`

, reverse the positives. Both the names of the comparisons and the numerical values are reversed. If`estimate.sign==0`

, return the argument. - ...
- other arguments not used.

### Values

The result is a `"multicomp"`

object containing the same contrasts as the argument but with the sign of the contrasts changed as needed.

### References

Heiberger, Richard M. and Holland, Burt (2004b). *Statistical Analysis and Data Display: An Intermediate Course with Examples in S-Plus, R, and SAS*. Springer Texts in Statistics. Springer. ISBN 0-387-40270-5.

Heiberger, Richard M. and Holland, Burt (2006). "Mean--mean multiple comparison displays for families of linear contrasts." *Journal of Computational and Graphical Statistics*, 15:937--955.

### Note

S-Plus use the `multicomp`

functions and R uses the `multcomp`

package.

### See Also

`MMC`

, `multicomp.order`

### Examples

`## see example in multicomp.order`

Documentation reproduced from package HH, version 3.1-31. License: GPL (>= 2)