unpack {cellWise}

Unpacks cellwise weighted data

Description

This function transforms a dataset X with cellwise weights W to an extended data matrix U with the same number of columns but more rows, and containing more NA's. Its rows have the case weights v.

Usage

unpack(X,W)

Arguments

X

An n by d data matrix or data frame. Must be given. X is allowed to contain NA's.

W

An n by d matrix of nonnegative cellwise weights. Must be given. W is not allowed to contain NA's.

Value

A list with components:

• U
  unpacked data matrix, with the same columns as X but typically more rows.

• V
  vector with the rowwise (=casewise) weights of U.

Author(s)

P.J. Rousseeuw

References

P.J. Rousseeuw (2023). Analyzing cellwise weighted data. Econometrics and Statistics, appeared online. doi:10.1016/j.ecosta.2023.01.007(link to open access pdf)

See Also

weightedEM, cwLocScat

Examples

X <- matrix(c(2.8, 5.3, 4.9, 7.4,
             2.3, 5.7, 4.3, 7.2,
             2.5, 5.1, 4.4, 7.6), nrow = 3, byrow = TRUE)
W <- matrix(c(0.8, 1.0, 0.3, 0.4, 
             0.3, 0.5, 0.9, 0.5, 
             1.0, 0.6, 0, 0.7), nrow = 3, byrow = TRUE)
rownames(X) <- rownames(W) <- c("A", "B", "C")
colnames(X) <- colnames(W) <- c("V1", "V2", "V3", "V4")
X
W
out <- unpack(X, W)
cbind(out$U, out$v)


# For more examples, we refer to the vignette:
## Not run: 
vignette("cellwise_weights_examples")

## End(Not run)