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added merge.data.frame patch for R base core

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talgalili committed Jan 15, 2012
1 parent 32369c1 commit 23916b38348d6be7e42801bbf5530d59f03c1472
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  1. +190 −0 merge.data.frame.r
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+#############
+# Explenation for the new keep_order parameter:
+# keep_order can accept the numbers 1 or 2, in which case it will make sure the resulting merged data.frame will be ordered according to the original order of rows of the data.frame entered to x (if keep_order=1) or to y (if keep_order=2). If keep_order is missing, merge will continue working as usual. If keep_order gets some input other then 1 or 2, it will issue a warning that it doesn't accept these values, but will continue working as merge normally would. Notice that the parameter "sort" is practically overridden when using keep_order (with the value 1 or 2).
+
+# an example is offered at the end of this code chunk
+
+merge.data.frame <- function (x, y, by = intersect(names(x), names(y)), by.x = by,
+ by.y = by, all = FALSE, all.x = all, all.y = all, sort = TRUE,
+ suffixes = c(".x", ".y"), incomparables = NULL, keep_order, ...)
+{
+ # if we use the "keep_order" parameter, we might need to modify either the x or y data.frame objects:
+ if(!missing(keep_order))
+ {
+
+ # some functions we will use soon:
+ add.id.column.to.data <- function(DATA)
+ {
+ data.frame(DATA, id... = seq_len(nrow(DATA)))
+ }
+ # example:
+ # add.id.column.to.data(data.frame(x = rnorm(5), x2 = rnorm(5)))
+ order.by.id...and.remove.it <- function(DATA)
+ {
+ # gets in a data.frame with the "id..." column. Orders by it and returns it
+ if(!any(colnames(DATA)=="id..."))
+ {
+ warning("The function order.by.id...and.remove.it is useful only for data.frame objects that includes the 'id...' order column")
+ return(DATA)
+ }
+
+
+ ss_r <- order(DATA$id...)
+ ss_c <- colnames(DATA) != "id..."
+ DATA[ss_r, ss_c]
+ }
+ # example:
+ # set.seed(3424)
+ # x <- data.frame(x = rnorm(5), x2 = rnorm(5))
+ # x2 <- add.id.column.to.data(x)[c(1,4,2,5,3),]
+ # x2
+ # order.by.id...and.remove.it(x2)
+
+ if(keep_order == 1) x<-add.id.column.to.data(x)
+ if(keep_order == 2) y<-add.id.column.to.data(y)
+ # if you didn't get 1 or 2 - issue a warning:
+ if(!any(keep_order == c(1,2))) warning("The parameter 'keep_order' in the function merge.data.frame only accepts the values 1 (for the x data.frame) or 2 (for the y data.frame)")
+
+ # sort <- FALSE
+ # notice that if sort was TRUE, using the keep_order parameter will eventually override it...
+ }
+
+ fix.by <- function(by, df) {
+ if (is.null(by))
+ by <- numeric()
+ by <- as.vector(by)
+ nc <- ncol(df)
+ if (is.character(by))
+ by <- match(by, c("row.names", names(df))) - 1L
+ else if (is.numeric(by)) {
+ if (any(by < 0L) || any(by > nc))
+ stop("'by' must match numbers of columns")
+ }
+ else if (is.logical(by)) {
+ if (length(by) != nc)
+ stop("'by' must match number of columns")
+ by <- seq_along(by)[by]
+ }
+ else stop("'by' must specify column(s) as numbers, names or logical")
+ if (any(is.na(by)))
+ stop("'by' must specify valid column(s)")
+ unique(by)
+ }
+ nx <- nrow(x <- as.data.frame(x))
+ ny <- nrow(y <- as.data.frame(y))
+ by.x <- fix.by(by.x, x)
+ by.y <- fix.by(by.y, y)
+ if ((l.b <- length(by.x)) != length(by.y))
+ stop("'by.x' and 'by.y' specify different numbers of columns")
+ if (l.b == 0L) {
+ nm <- nm.x <- names(x)
+ nm.y <- names(y)
+ has.common.nms <- any(cnm <- nm.x %in% nm.y)
+ if (has.common.nms) {
+ names(x)[cnm] <- paste(nm.x[cnm], suffixes[1L], sep = "")
+ cnm <- nm.y %in% nm
+ names(y)[cnm] <- paste(nm.y[cnm], suffixes[2L], sep = "")
+ }
+ if (nx == 0L || ny == 0L) {
+ res <- cbind(x[FALSE, ], y[FALSE, ])
+ }
+ else {
+ ij <- expand.grid(seq_len(nx), seq_len(ny))
+ res <- cbind(x[ij[, 1L], , drop = FALSE], y[ij[,
+ 2L], , drop = FALSE])
+ }
+ }
+ else {
+ if (any(by.x == 0L)) {
+ x <- cbind(Row.names = I(row.names(x)), x)
+ by.x <- by.x + 1L
+ }
+ if (any(by.y == 0L)) {
+ y <- cbind(Row.names = I(row.names(y)), y)
+ by.y <- by.y + 1L
+ }
+ row.names(x) <- NULL
+ row.names(y) <- NULL
+ if (l.b == 1L) {
+ bx <- x[, by.x]
+ if (is.factor(bx))
+ bx <- as.character(bx)
+ by <- y[, by.y]
+ if (is.factor(by))
+ by <- as.character(by)
+ }
+ else {
+ bx <- x[, by.x, drop = FALSE]
+ by <- y[, by.y, drop = FALSE]
+ names(bx) <- names(by) <- paste("V", seq_len(ncol(bx)),
+ sep = "")
+ bz <- do.call("paste", c(rbind(bx, by), sep = "\r"))
+ bx <- bz[seq_len(nx)]
+ by <- bz[nx + seq_len(ny)]
+ }
+ comm <- match(bx, by, 0L)
+ bxy <- bx[comm > 0L]
+ xinds <- match(bx, bxy, 0L, incomparables)
+ yinds <- match(by, bxy, 0L, incomparables)
+ if (nx > 0L && ny > 0L)
+ m <- .Internal(merge(xinds, yinds, all.x, all.y))
+ else m <- list(xi = integer(), yi = integer(), x.alone = seq_len(nx),
+ y.alone = seq_len(ny))
+ nm <- nm.x <- names(x)[-by.x]
+ nm.by <- names(x)[by.x]
+ nm.y <- names(y)[-by.y]
+ ncx <- ncol(x)
+ if (all.x)
+ all.x <- (nxx <- length(m$x.alone)) > 0L
+ if (all.y)
+ all.y <- (nyy <- length(m$y.alone)) > 0L
+ lxy <- length(m$xi)
+ has.common.nms <- any(cnm <- nm.x %in% nm.y)
+ if (has.common.nms)
+ nm.x[cnm] <- paste(nm.x[cnm], suffixes[1L], sep = "")
+ x <- x[c(m$xi, if (all.x) m$x.alone), c(by.x, seq_len(ncx)[-by.x]),
+ drop = FALSE]
+ names(x) <- c(nm.by, nm.x)
+ if (all.y) {
+ ya <- y[m$y.alone, by.y, drop = FALSE]
+ names(ya) <- nm.by
+ ya <- cbind(ya, x[rep.int(NA_integer_, nyy), nm.x,
+ drop = FALSE])
+ x <- rbind(x, ya)
+ }
+ if (has.common.nms) {
+ cnm <- nm.y %in% nm
+ nm.y[cnm] <- paste(nm.y[cnm], suffixes[2L], sep = "")
+ }
+ y <- y[c(m$yi, if (all.x) rep.int(1L, nxx), if (all.y) m$y.alone),
+ -by.y, drop = FALSE]
+ if (all.x)
+ for (i in seq_along(y)) is.na(y[[i]]) <- (lxy + 1L):(lxy +
+ nxx)
+ if (has.common.nms)
+ names(y) <- nm.y
+ res <- cbind(x, y)
+ if (sort)
+ res <- res[if (all.x || all.y)
+ do.call("order", x[, seq_len(l.b), drop = FALSE])
+ else sort.list(bx[m$xi]), , drop = FALSE]
+ }
+ attr(res, "row.names") <- .set_row_names(nrow(res))
+
+ if(!missing(keep_order) && any(keep_order == c(1,2))) return(order.by.id...and.remove.it(res))
+ # notice how it is essential to use && here, since if the first argument is false, it will not be possible to evaluate the second argument
+
+ res
+}
+
+
+
+
+if(F) # example
+{
+
+
+ merge( x.labels, x.vals, by='ref', all.y = T, sort=F )
+ merge( x.labels, x.vals, by='ref', all.y = T, sort=F ,keep_order = 2) # yay - works as we wanted it to...
+
+}

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