ggvis 交互式图形无法按预期使用反应值工作

我对以下示例有问题ggvis代码的目的是制作一个绘图，当您将鼠标悬停在该组的任何成员上时，突出显示整个点组。然后，我希望突出显示在您将鼠标悬停后立即消失。发生的情况是，突出显示最初起作用，但当您将鼠标悬停时，突出显示会保留下来，并且只有当您将鼠标悬停在另一组点上然后再次将鼠标悬停在它们上时才会消失。

library(magrittr)
library(dplyr)
library(ggvis)
library(shiny)

dat <- iris %>% select(-Species) %>% dist %>% cmdscale %>% data.frame %>% tbl_df %>% mutate(Species = iris$Species) %>% 
data.frame
Props <- reactiveValues(Size = rep(50, length.out = nrow(dat)), Stroke = rep("white", length.out = nrow(dat)))
hoveron <- function(data, ...) {
    Props$Size[dat$Species == data$Species] <- 150 
    print("hoveron!")
    Props$Stroke[dat$Species == data$Species] <- "black"
}
hoveroff <- function(...) {
    Props$Size <- rep(50, length.out = nrow(dat))
    print("hoveroff!")
    Props$Stroke <- rep("white", length.out = nrow(dat))
}

dat %>%
ggvis(~X1, ~X2, fill = ~Species) %>% layer_points(size = reactive(Props$Size), stroke = reactive(Props$Stroke))  %>%
scale_numeric("size", range = c(80, 180)) %>% scale_numeric("x", label = "MDS Axis 1") %>%
scale_numeric("y", label = "MDS Axis 2") %>% scale_ordinal("stroke", sort = TRUE, domain = c("black", "white"), range = c("black", "white")) %>%
add_legend(scales = "size", properties = legend_props(title = list(fontSize = 0), labels = list(fontSize = 0), symbols = list(size = 0))) %>%
add_legend(scales = "stroke", properties = legend_props(title = list(fontSize = 0), labels = list(fontSize = 0), symbols = list(size = 0))) %>%
set_options(duration = 0) %>% handle_hover(hoveron, hoveroff)

您可以在此处以闪亮应用程序的形式查看结果：https://ecologician.shinyapps.io/ggvis_grouping_wrong/ https://ecologician.shinyapps.io/ggvis_grouping_wrong/. Note: The print语句用于调试。hoveroff当您离开第一组点时似乎会触发，但随后hoveron之后立即触发， data$Species 等于刚刚悬停的数据。我无法完全解释为什么。我希望这只是一个我目前看不到的简单错误。这里有人能看出出了什么问题吗？

更多细节：

上面的代码是尝试制作下面代码的不太冗长/更简单的版本，它确实按照我的预期工作：

library(magrittr)
library(dplyr)
library(ggvis)
library(shiny)

hoverset <- reactiveValues(setosa = 0, versicolor = 0, virginica = 0)
hoveron <- function(data, ...) {
    hoverset[[data$Species]] <- 1
}
hoveroff <- function(data, ...) {
    hoverset$setosa <- 0
    hoverset$versicolor <- 0
    hoverset$virginica <- 0
}

dat <- iris %>% select(-Species) %>% dist %>% cmdscale %>% data.frame %>% tbl_df %>% mutate(Species = iris$Species) %>% 
mutate(Size = 50, Stroke = "white") %>% data.frame
dat2 <- reactive({
    if (hoverset$setosa == 1){
        dat[dat[,"Species"] == "setosa","Size"] <<- 150
        dat[dat[,"Species"] == "setosa","Stroke"] <<- "black"
    } else {
        dat[dat[,"Species"] == "setosa","Size"] <<- 50
        dat[dat[,"Species"] == "setosa","Stroke"] <<- "white"
    }
    if (hoverset$versicolor == 1){
        dat[dat[,"Species"] == "versicolor","Size"] <<- 150
        dat[dat[,"Species"] == "versicolor","Stroke"] <<- "black"
    } else {
        dat[dat[,"Species"] == "versicolor","Size"] <<- 50
        dat[dat[,"Species"] == "versicolor","Stroke"] <<- "white"
    }
    if (hoverset$virginica == 1){
        dat[dat[,"Species"] == "virginica","Size"] <<- 150
        dat[dat[,"Species"] == "virginica","Stroke"] <<- "black"
    } else {
        dat[dat[,"Species"] == "virginica","Size"] <<- 50
        dat[dat[,"Species"] == "virginica","Stroke"] <<- "white"
    }
    dat
})

dat2 %>%
ggvis(~X1, ~X2, fill = ~Species) %>% layer_points(size = ~Size, stroke = ~Stroke)  %>%
scale_numeric("size", range = c(80, 180)) %>% scale_numeric("x", label = "MDS Axis 1") %>%
scale_numeric("y", label = "MDS Axis 2") %>% scale_ordinal("stroke", sort = TRUE, domain = c("black", "white"), range = c("black", "white")) %>%
add_legend(scales = "size", properties = legend_props(title = list(fontSize = 0), labels = list(fontSize = 0), symbols = list(size = 0))) %>%
add_legend(scales = "stroke", properties = legend_props(title = list(fontSize = 0), labels = list(fontSize = 0), symbols = list(size = 0))) %>%
set_options(duration = 0) %>% handle_hover(hoveron, hoveroff)

在这里查看这个应用程序：https://ecologician.shinyapps.io/ggvis_grouping/ https://ecologician.shinyapps.io/ggvis_grouping/

Thanks!