For multiple membership models, translates matrix into a data.frame formatted for MLwiNTranslates a matrix into a form usable by MLwiN for multiple membership models, namely a data.frame with (a) columns containing membership IDs (if first row matrix is 0 1 1 0 1 1, then first row of generated ID vectors would be, say, 2, 3, 5, 6) and (b) columns containing weights (in this example, if standardise = TRUE, then first row of generated weight vectors would be, say, 0.25, 0.25, 0.25, 0.25, otherwise first row of generated weight vectors would be, say, 1, 1, 1, 1).