dat.sel: Generate Pairwise Data Set
In mt: Metabolomics Data Analysis Toolbox

Description Usage Arguments Details Value Author(s) See Also Examples

Generate index or data set of pairwise combination based on class labels.

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  combn.pw(cls, choices = NULL) 
  
  dat.sel(dat, cls, choices = NULL)

`dat`	A data frame or matrix of data set.
`cls`	A factor or vector of class labels or categorical data.
`choices`	The vector or list of class labels to be chosen for binary combination.

If choices is NULL, all binary combinations will be computed. If choices has one class label, the comparisons between this one and any other classes will be calculated. If choices has more than two classes, all binary combinations in choices will be generated. For details, see examples below.

combn.pw returns a data frame of index (logical values).

dat.set returns a list of list with components:

`dat`	Pairwise data set.
`cls`	Pairwise class label.

Wanchang Lin

Applications of dat.sel in pca.plot.wrap, lda.plot.wrap and pls.plot.wrap.

data(iris)
x <- subset(iris, select = -Species)
y <- iris$Species
 
## generate data set with class "setosa" and "virginica"
binmat.1 <- dat.sel(x,y,choices=c("setosa","virginica"))
names(binmat.1)

## generate data sets for "setosa" vs other classes. These are: 
## "setosa" and "versicolor", "setosa" and "virginica".
binmat.2 <- dat.sel(x,y,choices=c("setosa"))
names(binmat.2)

## generate data set with combination of each class. These are:  
## "setosa" and "versicolor", "setosa" and "virginica",  
## "versicolor" and "virginica" 
binmat.3 <- dat.sel(x,y,choices= NULL)
names(binmat.3)

data(abr1)
cls <- factor(abr1$fact$class)
dat <- preproc(abr1$pos, method="log")

## There are some examples of 'choices'
choices <- c("2")
choices <- c("2","3","4")
choices <- list(c("2","3"),c("4","5"))
choices <- NULL
idx <- combn.pw(cls,choices=choices)  

dat.pw <- dat.sel(dat, cls,choices=choices)