plotSEPprm: Plot trimmed SEP from repeated DCV of PRM

In chemometrics: Multivariate Statistical Analysis in Chemometrics

Plot trimmed SEP from repeated DCV of PRM

Description

Generate plot showing trimmed SEP values for Repeated Double Cross Validation for Partial RObust M-Regression (PRM)

Usage

plotSEPprm(prmdcvobj, optcomp, y, X, complete = TRUE, ...)

Arguments

prmdcvobj	object from repeated double-CV of PRM, see prm_dcv
optcomp	optimal number of components
y	data from response variable
X	data with explanatory variables
complete	if TRUE the trimmed SEPcv values are drawn and computed from prm_cv for the same range of components as included in the prmdcvobj object; if FALSE only optcomp components are computed and their results are displayed
...	additional arguments ofr prm_cv

Details

After running repeated double-CV for PRM, this plot visualizes the distribution of the SEP values. While the gray lines represent the resulting trimmed SEP values from repreated double CV, the black line is the result for standard CV with PRM, and it is usually too optimistic.

Value

SEPdcv	all trimmed SEP values from repeated double-CV
SEPcv	trimmed SEP values from usual CV

Author(s)

Peter Filzmoser <[e-mail]>

References

K. Varmuza and P. Filzmoser: Introduction to Multivariate Statistical Analysis in Chemometrics. CRC Press, Boca Raton, FL, 2009.

See Also

prm

Examples

data(NIR)
X <- NIR$xNIR[1:30,]      # first 30 observations - for illustration
y <- NIR$yGlcEtOH[1:30,1] # only variable Glucose
NIR.Glc <- data.frame(X=X, y=y)
res <- prm_dcv(X,y,a=4,repl=2)
plot1 <- plotSEPprm(res,opt=res$afinal,y,X)

chemometrics documentation built on Aug. 25, 2023, 5:18 p.m.