Selection functions
.SEL(x, ...).X(x)
# S3 method for data.frame
.X(x)
# S3 method for list
.X(x)
# S3 method for default
.X(x, ...)
.Y(x)
# S3 method for data.frame
.Y(x)
# S3 method for list
.Y(x)
# S3 method for default
.Y(x, ...)
.G(x)
# S3 method for data.frame
.G(x)
# S3 method for list
.G(x)
# S3 method for default
.G(x, ...)
input data to be subeseted
aditional parameters