# [R] How would I color points conditional on their value in a plot of a time series

Eivind K. Dovik he||o @end|ng |rom e|v|nddov|k@com
Tue May 1 23:18:51 CEST 2018

```You may also want to check this out:

plot(ttt, type = "p")
points(ttt, col = ifelse(ttt < 8, "black", "red"))

Eivind K. Dovik
Bergen, NO

On Tue, 1 May 2018, Christopher W Ryan wrote:

> Excellent! Worked like a charm. Thanks.
>
> --Chris Ryan
>
> On Tue, May 1, 2018 at 4:33 PM, William Dunlap <wdunlap using tibco.com> wrote:
>
>> The ts method for plot() is quirky.  You can use the default method:
>>
>>  plot(as.vector(time(ttt)), as.vector(ttt), type = "p", col=ifelse(ttt<8,
>> "black", "red"))
>>
>>
>> Bill Dunlap
>> TIBCO Software
>> wdunlap tibco.com
>>
>> On Tue, May 1, 2018 at 1:17 PM, Christopher W Ryan <cryan using binghamton.edu>
>> wrote:
>>
>>> How would I color points conditional on their value in a plot of a time
>>> series.  Something like this:
>>>
>>> ## demonstration data
>>> ttt <- ts(rpois(12, lambda = 8), start = c(2000, 1), freq = 4)
>>> ttt
>>> plot(ttt, type = "p")
>>>
>>> ## doesn't work--all points the same color
>>> plot(ttt, type = "p", col = ifelse(ttt < 8, "black", "red"))
>>>
>>> ## also doesn't work--all points the same color
>>> q <- as.numeric(ttt)
>>> q
>>> plot(ttt, type = "p", col = ifelse(q < 8, "black", "red"))
>>>
>>>
>>> ## works OK with a simple, non-time-series scatterplot, as in
>>>
>>> sss <- data.frame(x = rpois(12, lambda = 8), y = rnorm(12, mean = 100, sd
>>> =
>>> 25))
>>> with(sss, plot(y ~ x, col = ifelse(y > 100, "black", "red")))
>>>
>>> ## but I am missing something about time series.
>>>
>>> Thanks.
>>>
>>> --Chris Ryan
>>> Broome County Health Department
>>> and Binghamton University
>>> Binghamton, NY
>>>
>>>         [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> ng-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help