13.5 气泡图

简单图形 scatter，分布图几类，其中 scatter、heatmap、scatterpolar 支持 WebGL 绘图引擎

# https://plotly.com/r/bubble-charts/
dat <- diamonds[, .(
  carat = mean(carat),
  price = sum(price), 
  cnt = .N
), by = .(cut)]

plot_ly(
  data = dat, colors = "Greys",
  x = ~carat, y = ~price, color = ~cut, size = ~cnt,
  type = "scatter", mode = "markers",
  marker = list(
    symbol = "circle", sizemode = "diameter",
    line = list(width = 2, color = "#FFFFFF"), opacity = 0.4
  ),
  text = ~ paste(
    sep = " ", "重量：", round(carat, 2), "克拉",
    "<br>价格:", round(price / 10^6, 2), "百万"
  ),
  hoverinfo = 'text'
) %>%
  add_annotations(
    x = ~carat, y = ~price, text = ~cnt,
    showarrow = F, font = list(family = "sans")
  ) %>%
  layout(
    xaxis = list(hoverformat = ".2f"),
    yaxis = list(hoverformat = ".0f")
  )

图 13.5: 气泡图