r - Plotly:如何根据值指定符号和颜色？

Question

使用 plotly 绘图时在 R 中，如何根据值指定颜色和符号？例如使用 mtcars示例数据集，如果 mtcars$mpg 如何绘制为红色方块是大于还是小于 18？

例如:

library(plotly)


p <- plot_ly(type = "scatter", data = mtcars, x = rownames(mtcars), y = mtcars$mpg,
             mode = "markers" )

如何将所有高于 20 的点作为黄色方块？

Answer 1

你可以做这样的事情:

plot_ly(type = "scatter", data = mtcars, x = rownames(mtcars), y = mtcars$mpg,
        mode = "markers", symbol = ~mpg > 20, symbols = c(16,15),
        color = ~mpg > 20, colors = c("blue", "yellow"))

https://plot.ly/r/line-and-scatter/#mapping-data-to-symbols

是的，这是可能的，我会在 plot_ly() 之外制作您所有的分组和形状/颜色规范。与 cut()第一的。然后利用文字 I() plot_ly() 内部的语法引用您的新颜色和形状变量时:

data(mtcars)

mtcars$shape <- cut(mtcars$mpg,
                    breaks = c(0,18, 26, 100),
                    labels = c("square", "circle", "diamond"))
mtcars$color <- cut(mtcars$mpg,
                    breaks = c(0,18, 26, 100),
                    labels = c("red", "yellow", "green"))

plot_ly(type = "scatter", data = mtcars, x = rownames(mtcars), y = mtcars$mpg,
        mode = "markers", symbol = ~I(shape), color = ~I(color))