图例中的Colorbar

Question

以下是我的数据：

set.seed(42)
mydata = data.frame(A = rnorm(20), B = rnorm(20), Index = sample(190:400,20))    

我尝试根据Index值将数据划分为20个不同的间隔，然后根据它们的间隔value对散点进行着色。下面是我的代码。它不能完美地工作。

cols = colorRampPalette(c("red", "black"), space = "rgb")(20)
mydata$interval = cut(mydata$Index,breaks = 20)
mydata$cols = cols[mydata$interval]
require(plotly)
x = list(title = "A")
y = list(title = "B")
plot_ly(mydata, x = ~A, y = ~B,  color = ~cols, type = "scatter",
                        mode = 'markers', hoverinfo = 'text',
                        text = ~paste(interval)) %>%
                        layout(xaxis = x, yaxis = y)

如何在颜色基于Index值的图例中获取colorbar。

Answer 1

你在找这个吗：

plot_ly(mydata, x = ~A, y = ~B, type = "scatter",
        mode = 'markers', hoverinfo = 'text', colors = colorRampPalette(c("red", "black"), space = "rgb")(20), color = ~Index, text = ~paste(interval), marker = list(size=14)) %>%
        layout(xaxis = x, yaxis = y) %>%
        colorbar(title = "My Legend")