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rprojection

projection graph in r

How can I create a projection graph as appears on this page: http://www.businessinsider.in/Heres-A-Terrifying-Chart-Of-Projected-Ebola-Cases/articleshow/43259377.cms

My data:

> ddf
  time value
1    1    10
2    2    18
3    3    30
4    4    38
5    5    45
6    6    61
7    7    78
> 
> dput(ddf)
structure(list(time = 1:7, value = c(10L, 18L, 30L, 38L, 45L, 
61L, 78L)), .Names = c("time", "value"), class = "data.frame", row.names = c(NA, 
-7L))

I want to project it to time 20.

Solution

  • You can use ggplot2's stat_smooth function with a forecasting method of your choise. Use fullrange=TRUE to predict it for the whole range.

    require(ggplot2)
ggplot(aes(x=time,y=value), data=ddf) + geom_point() + 
  stat_smooth(method="lm", fullrange=TRUE, lty="dotdash") + xlim(1,20) +
  stat_smooth(method="lm")

    enter image description here

    If you also want the vertical line: Add + geom_vline(xintercept=7)