R/lav_dataframe.R

In lavaan: Latent Variable Analysis

# data.frame utilities
# Y.R. 11 April 2013

# - 10 nov 2019: * removed lav_dataframe_check_vartype(), as we can simply use
#                  sapply(lapply(frame, class), "[", 1L) (unused anyway)
#                * removed lav_dataframe_check_ordered() as we can simply use
#                  any(sapply(frame[, ov.names], inherits, "ordered"))

# construct vartable, but allow 'ordered/factor' argument to intervene
# we do NOT change the data.frame
lav_dataframe_vartable <- function(frame = NULL, ov.names = NULL,
                                   ov.names.x = NULL,
                                   ordered = NULL,
                                   factor = NULL,
                                   as.data.frame. = FALSE) {

    if(missing(ov.names)) {
        var.names <- names(frame)
    } else {
        ov.names   <- unlist(ov.names, use.names = FALSE)
        ov.names.x <- unlist(ov.names.x, use.names = FALSE)
        var.names  <- unique(c(ov.names, ov.names.x))
    }
    nvar <- length(var.names)
    var.idx <- match(var.names, names(frame))


    nobs <- integer(nvar)
    type <- character(nvar)
    user <- integer(nvar)
    exo  <- ifelse(var.names %in% ov.names.x, 1L, 0L)
    mean <- numeric(nvar); var <- numeric(nvar)
    nlev <- integer(nvar); lnam <- character(nvar)
    for(i in seq_len(nvar)) {
        x <- frame[[var.idx[i]]]

        type.x <- class(x)[1L]

        # correct for matrix with 1 column
        if(inherits(x, "matrix") && (is.null(dim(x)) ||
                                    (!is.null(dim) && ncol(x) == 1L))) {
            type.x <- "numeric"
        }

        # correct for integers
        if(inherits(x, "integer")) {
            type.x <- "numeric"
        }

        # handle the 'labelled' type from the haven package
        # - if the variable name is not in 'ordered', we assume
        #   it is numeric (for now) 11 March 2018
        if(inherits(x, "labelled") && !(var.names[i] %in% ordered)) {
            type.x <- "numeric"
        }

        # handle ordered/factor
        if(!is.null(ordered) && var.names[i] %in% ordered) {
            type.x <- "ordered"
            lev <- sort(unique(x)) # we assume integers!
            nlev[i] <- length(lev)
            lnam[i] <- paste(lev, collapse="|")
            user[i] <- 1L
        } else if(!is.null(factor) && var.names[i] %in% factor) {
            type.x <- "factor"
            lev <- sort(unique(x)) # we assume integers!
            nlev[i] <- length(lev)
            lnam[i] <- paste(lev, collapse="|")
            user[i] <- 1L
        } else {
            nlev[i] <- nlevels(x)
            lnam[i] <- paste(levels(x), collapse="|")
        }

        type[i] <- type.x
        nobs[i] <- sum(!is.na(x))
        mean[i] <- ifelse(type.x == "numeric", mean(x, na.rm=TRUE),
                          as.numeric(NA))
        var[i]  <- ifelse(type.x == "numeric", var(x, na.rm=TRUE),
                          as.numeric(NA))
    }

    VAR <- list(name=var.names, idx=var.idx, nobs=nobs, type=type, exo=exo,
                user=user, mean=mean, var=var, nlev=nlev, lnam=lnam)

    if(as.data.frame.) {
        VAR <- as.data.frame(VAR, stringsAsFactors = FALSE,
                             row.names = 1:length(VAR$name))
        class(VAR) <- c("lavaan.data.frame", "data.frame")
    }

    VAR
}