如 cmets 中所述，此警告是由使用 reorder_by() 函数引起的，但只能与 ggplot2 结合使用。具体来说，由于某种原因，这些级别是重复的：
#> levels(d2$id)
[1] "Sepal.Width" "Sepal.Width" "Sepal.Length" "Sepal.Length" "Petal.Width" "Petal.Width" "Petal.Length"
[8] "Petal.Length"
ggplot2 不喜欢重复级别，因此会发出警告。
如果有人有兴趣，我编写了新代码来重新调整自己以避免这个问题并避免对plotflow 包的依赖。
新功能是这样的：
#' Plot multiple factor loadings in one plot.
#'
#' Returns a ggplot2 plot with sorted loadings colored by the analysis they belong to. Supports reversing óf any factors that are reversed. Dodges to avoid overplotting. Only works for factor analyses with 1 factor solutions!
#' @param fa_objects (list of fa-class objects) Factor analyses objects from the fa() function from the \code{\link{psych}} package.
#' @param fa_labels (chr vector) Names of the analyses. Defaults to fa.1, fa.2, etc..
#' @param reverse_vector (num vector) Vector of numbers to use for reversing factors. Use e.g. c(1, -1) to reverse the second factor. Defaults not reversing.
#' @param reorder (chr scalar or NA) Which factor analysis to order the loadings by. Can be integers that reprensent each factor analysis. Can also be "mean", "median" to use the means and medians of the loadings. Use "all" for the old method. Default = "mean".
#' @export
#' @examples
#' library(psych)
#' plot_loadings_multi(fa(iris[-5])) #extract a factor and reverse
plot_loadings_multi = function (fa_objects, fa_labels, reverse_vector = NA, reorder = "mean") {
library("stringr")
library("ggplot2")
library("plyr")
fa_num = length(fa_objects)
fa_names = str_c("fa.", 1:fa_num)
if (!is.list(fa_objects)) {
stop("fa_objects parameter is not a list.")
}
if (class(fa_objects) %in% c("psych", "fa")) {
fa_objects = list(fa_objects)
fa_num = length(fa_objects)
fa_names = str_c("fa.", 1:fa_num)
}
if (missing("fa_labels")) {
if (!is.null(names(fa_objects))) {
fa_labels = names(fa_objects)
}
else {
fa_labels = fa_names
}
}
if (length(fa_labels) != fa_num) {
stop("Factor analysis labels length is not identical to number of analyses.")
}
if (all(is.na(reverse_vector))) {
reverse_vector = rep(1, fa_num)
}
else if (length(reverse_vector) != fa_num) {
stop("Length of reversing vector does not match number of factor analyses.")
}
d = data.frame()
for (fa.idx in 1:fa_num) {
loads = fa_objects[[fa.idx]]$loadings * reverse_vector[fa.idx]
rnames = rownames(loads)
loads = as.data.frame(as.vector(loads))
rownames(loads) = rnames
colnames(loads) = fa_names[fa.idx]
suppressor({
d = merge_datasets(d, loads, 1)
})
}
d2 = reshape(d, varying = 1:fa_num, direction = "long", ids = rownames(d))
d2$time = as.factor(d2$time)
d2$id = as.factor(d2$id)
colnames(d2)[2] = "fa"
#reorder factor?
if (!is.na(reorder)) {
if (reorder == "all") {
library("plotflow")
silence({
d2 = reorder_by(id, ~fa, d2)
})
} else if (reorder == "mean") {
v_aggregate_values = daply(d2, .(id), function(x) {
mean(x$fa)
})
#re-level
d2$id = factor(d2$id, levels = names(sort(v_aggregate_values, decreasing = F)))
} else if (reorder == "median") {
v_aggregate_values = daply(d2, .(id), function(x) {
median(x$fa)
})
#re-level
d2$id = factor(d2$id, levels = names(sort(v_aggregate_values, decreasing = F)))
} else {
d2_sub = d2[d2$time == reorder, ] #subset the analysis whose loading is to be used for the reorder
silence({
d2_sub = reorder_by(id, ~fa, d2_sub)
})
library(gdata)
d2$id = reorder.factor(d2$id, new.order = levels(d2_sub$id))
}
}
#plot
g = ggplot(d2, aes(x = id, y = fa, color = time, group = time)) +
geom_point(position = position_dodge(width = 0.5)) +
ylab("Loading") + xlab("Indicator") + scale_color_discrete(name = "Analysis",
labels = fa_labels) + coord_flip()
return(g)
}
library(psych)
fa_1 = fa(iris[-5])
fa_2 = fa(iris[1:125, -5])
plot_loadings_multi(list(fa_1, fa_2), reorder = "mean")
这会产生以下没有警告的情节：
代码来自my personal package。