R语言dygraphs报错：Unsupported type passed to argument 'data' 解决方法

问题场景 #

用dygraphs包制作堆叠图，先模拟了如下时间序列数据：

library(dygraphs)

set.seed(1)
date <- seq(as.Date("2010-01-01"), as.Date("2010-12-01"), by = "month")
var1 <- rnorm(length(date), mean = 100, sd = 10)
var2 <- rnorm(length(date), mean = 50, sd = 5)
df <- data.frame(date, var1, var2)

运行绘图代码时触发错误：

dygraph(df, main = "Stacked Graph") %>%
  dySeries("var1", label = "Var1") %>%
  dySeries("var2", label = "Var2") %>%
  dyOptions(stackedGraph = TRUE) %>%
  dyRangeSelector(height = 20)

报错信息：

Error in dygraph(df, main = "Stacked Graph") : 
  Unsupported type passed to argument 'data'.

报错原因 #

dygraphs的核心函数dygraph()仅支持xts、ts或zoo类型的时间序列数据作为输入，直接传入普通数据框会因类型不兼容触发该错误。

解决方案 #

通过xts包将数据框转换为xts格式后再传入dygraph()，代码如下：

library(xts)
# 将数据框转换为xts对象：提取数值列，指定日期为索引
df_xts <- xts(df[,-1], order.by = df$date)

# 重新绘制堆叠图
dygraph(df_xts, main = "Stacked Graph") %>%
  dySeries("var1", label = "Var1") %>%
  dySeries("var2", label = "Var2") %>%
  dyOptions(stackedGraph = TRUE) %>%
  dyRangeSelector(height = 20)

内容的提问来源于stack exchange，提问作者stats_noob