R help - May 2018 - How would I color points conditional on their value in a plot of a time series

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

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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 at
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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/
> posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
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Excellent! Worked like a charm. Thanks.

--Chris Ryan

On Tue, May 1, 2018 at 4:33 PM, William Dunlap <wdunlap at 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 at
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 at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posti
>> ng-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
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