Last data update: 2014.03.03

R: Robust Boosting Path for Truncated Loss Functions
rbstpathR Documentation

Robust Boosting Path for Truncated Loss Functions

Description

Gradient boosting path for optimizing robust loss functions with componentwise linear, smoothing splines, tree models as base learners.

Usage

rbstpath(x, y, rmstop=seq(40, 400, by=20), ctrl=bst_control(), del=1e-16, ...)

Arguments

x

a data frame containing the variables in the model.

y

vector of responses. y must be in {1, -1}.

rmstop

vector of boosting iterations

ctrl

an object of class bst_control.

del

convergency critera

...

arguments passed to rbst

Details

This function invokes rbst with mstop being each element of vector rmstop. It can provide different paths. Thus rmstop serves as another hyper-parameter. However, the most important hyper-parameter is the loss truncation point.

Value

A length rmstop vector of lists with each element being an object of class rbst.

Author(s)

Zhu Wang

See Also

rbst

Examples

x <- matrix(rnorm(100*5),ncol=5)
c <- 2*x[,1]
p <- exp(c)/(exp(c)+exp(-c))
y <- rbinom(100,1,p)
y[y != 1] <- -1
y[1:10] <- -y[1:10]
x <- as.data.frame(x)
dat.m <- bst(x, y, ctrl = bst_control(mstop=50), family = "hinge", learner = "ls")
predict(dat.m)
dat.m1 <- bst(x, y, ctrl = bst_control(twinboost=TRUE, 
coefir=coef(dat.m), xselect.init = dat.m$xselect, mstop=50))
dat.m2 <- rbst(x, y, ctrl = bst_control(mstop=50, s=0, trace=TRUE), 
rfamily = "thinge", learner = "ls")
predict(dat.m2)
rmstop <- seq(10, 40, by=10)
dat.m3 <- rbstpath(x, y, rmstop, rfamily = "thinge", learner = "ls")

Results