```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = FALSE)
load("HadCRUT4-gl-download20170601.RData")

temp$min = apply(temp[month.abb], 1, min, na.rm = TRUE)
temp$max = apply(temp[month.abb], 1, max, na.rm = TRUE)
temp$abs_max = abs(temp$max - temp$min)
temp$abs_annual = abs(temp$Annual)

library(googleVis)
```


There is no way to add annotation for *reference period* in `googleVis`.


```{r, results = 'asis'}
p = gvisAreaChart(temp, "Year", c("min", "Annual", "abs_max"),
                  options = list(width = 800, height = 500, isStacked = TRUE, 
                                 vAxes = "[{title: 'Temperature anomaly'}]",
                                 legend = "{position: 'none'}",
                                 series = "[{type: 'area', color: 'transparent'}, {type: 'line', color: 'steelblue'},                                                  {type: 'area', color: 'lightblue', areaOpacity: 1}]"))
# for viewing into RStudio 
# plot(p, browser = rstudioapi::viewer)
p
```


