Plotly双Y轴绘图折线图异常，如何保证折线与柱状图共用同一X轴

问题核心原因 #

• 原始数据集未生成MonthName字段，无法和x轴配置中指定的month.name排序规则匹配，导致不同图层的x轴取值错位
• y轴与对应数值范围绑定错误，数据超出坐标轴显示范围，导致折线消失或显示异常

修正方案 #

先给数据集新增和数字月份一一对应的月份名称字段，同时调整y轴范围和对应指标的绑定关系，初始绘图时统一指定全局x轴，后续所有图层默认复用同一个x轴即可：

library(plotly)
# 构造数据集，新增月份名称列
temprain<-data.frame(month = c(1:12), 
                     Train = c(250,220, 180,97,38,27,31,47,70,140,200,250), 
                     Tair = c(17,16, 15,13,9,6,5,9,12,13,14,16))
temprain$MonthName <- month.name[temprain$month]

# 定义两个指标的坐标轴范围
tempseq<-seq(0,20,by=0.5) # 气温数值范围
rainseq<-seq(0,260,by=1) # 降雨量数值范围

# x轴配置
xlab<-list(type = "category",
           categoryorder = "array",
           categoryarray = month.name,
           showgrid = TRUE,
           showline = TRUE,
           autorange = FALSE, # 关闭自动范围，保证按指定的月份顺序显示
           showticklabels = TRUE,
           ticks = "outside",
           tickangle = 0
)

# 绘图，初始调用统一指定x轴
plot_ly(temprain, x = ~MonthName) %>%
  add_bars(y = ~Train, type = "bar", name = "降雨量", yaxis = "y") %>%
  add_lines(y = ~Tair, name = "气温", yaxis = "y2") %>%
  layout(xaxis = xlab,
         yaxis = list(showline = TRUE, side = "left",
                      title = "降雨量(mm)", range = rainseq),
         yaxis2 = list(showline = TRUE, side = "right",
                       overlaying = "y",  title = "气温(℃)", range = tempseq),
         showlegend = TRUE,
         margin = list(pad = 0, b = 50, l = 50, r = 50))

内容的提问来源于stack exchange，提问作者Kyle Finn