在ggvis中過濾圖例

Question

在此ggvis示例中，是否有一種方法可以過濾圖例以反映輸入選擇，例如，當未選擇“ z”時僅顯示“ x”和“ y”？ 如果選擇范圍廣，這將特別有用。

library(tidyverse)
library(ggvis)

data_df <- tibble(
  name = factor(c("x", "x", "x", "y", "y", "y", "z", "z", "z")), 
  quant = c(7, 8, 7, 8, 8, 8, 9, 9, 9), 
  year = factor(c(2014, 2015, 2016, 2014, 2015, 2016, 2014, 2015, 2016))
  )

data_df %>%
  ggvis(~ year, ~ quant, stroke = ~ name) %>%
  filter(name %in% eval(
    input_select(
      choices = levels(data_df$name),
      selected = c("x", "y"),
      selectize = TRUE,
      multiple = TRUE
    )
  )) %>%
  layer_lines()

Answer 1

我想這就是你想要的嗎？

library(tidyverse)
library(ggvis)

data_df <- tibble(
  name = c("x", "x", "x", "y", "y", "y", "z", "z", "z"), 
  quant = c(7, 8, 7, 8, 8, 8, 9, 9, 9), 
  year = factor(c(2014, 2015, 2016, 2014, 2015, 2016, 2014, 2015, 2016))
)

data_df %>%
  ggvis(~ year, ~ quant, stroke = ~ name) %>%
  filter(name %in% eval(
    input_select(
      choices = levels(as.factor(data_df$name)),
      selected = c("x", "y"),
      selectize = TRUE,
      multiple = TRUE
    )
  )) %>%
  layer_lines()