如何基于y位置动态更改标记点的颜色

Question

我在下面有使用highchart中的js R库的交互式绘图

library(highcharter)
hchart(data.frame('Date' = seq(Sys.Date(), Sys.Date() - 10, by = '-1 day'), 'Value' = sample(c(-1, 1), 11, replace = T), 'variable' = 'aa') %>% mutate(color = ifelse(Value < 0, "#41c83b", "#E0245E")), 
                            "line", 
                            zIndex = 1, opacity = 0.9,
                            hcaes(x = Date, y = Value, group = variable),
                            zones = list(list(value = 0, color = hex_to_rgba("#41c83b", 1)), list(color = hex_to_rgba("#E0245E", 1))),
                            marker = list(fillColor = "#fff", lineColor = '#000', radius = 5, lineWidth = 2))

我想根据基于markers动态的线条颜色来匹配y-value的颜色。当前所有标记的颜色设置为我不想要的black。

任何指针如何动态更改颜色将非常有帮助

Answer 1

API中没有此类选项。您需要编写一些自定义代码。最简单的方法是使用chart.events.load事件，遍历系列中的所有点，在红色或绿色区域中找到它们，并分别更新其标记选项。要在R中编写JavaScript代码，可以使用JS（“”）函数。

这里是完整的示例代码：

library(highcharter)
hchart(data.frame('Date' = seq(Sys.Date(), Sys.Date() - 10, by = '-1 day'), 'Value' = sample(c(-1, 1), 11, replace = T), 'variable' = 'aa') %>%
         mutate(color = ifelse(Value < 0, "#41c83b", "#E0245E")), 
       "line", 
       zIndex = 1, opacity = 0.9,
       hcaes(x = Date, y = Value, group = variable),
       zones = list(list(value = 0, color = hex_to_rgba("#41c83b", 1)), list(color = hex_to_rgba("#E0245E", 1))),
       marker = list(fillColor = "#fff", radius = 5, lineWidth = 2)) %>%
  hc_chart(events = list(load = JS("function () {
    this.series[0].points.forEach(function (point) {
      if (point.y > 0) {
        point.update({
          marker: {
            lineColor: 'red'
          }
        }, false);
      } else {
        point.update({
          marker: {
            lineColor: 'green'
          }
        }, false);
      }
    });
    this.redraw();
  }")))

API参考：https://api.highcharts.com/highcharts/chart.events.loadhttps://api.highcharts.com/class-reference/Highcharts.Chart#updatehttps://api.highcharts.com/class-reference/Highcharts.Point#update