# Package ‘gamm4.test’ in R

## Package “gamm4.test” in R

gamm4.test is a package supplied with R for testing nonlinear curve and surface functions.The main testing routine is gam.test.

## Documentation

The major advantages of this packages are:

• Arguements formulated are consistent with semiparametric regression estimating package “mgcv” and “gamm4”, so that people who are familiar with these ones can easily adopt our major function gam.grptest().

• We allow parallel computing by specifying parallel = TRUE within function gam.grptest to save computational time if needed.

• plot.gamtest() function plots semiparametric estimated nonlinear curves and surfaces via R package “plotly”. Option type=plotly.persp provides a 3-D interactive plot with estimated regression functions for individual groups. Also, test.statistic = TRUE provides the empirical distribution of the test statistic under the null hypothesis of equal regression function.