Skip to content

How would I color points conditional on their value in a plot of a time series

5 messages · William Dunlap, Christopher W. Ryan, Eivind K. Dovik +1 more

Christopher W. Ryan
# 
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
William Dunlap
# 
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:

  
  


  


      

    

    

      
      

        


  

        

      Christopher W. Ryan
    

    

      
      #
    

  


  

      
Excellent! Worked like a charm. Thanks.

--Chris Ryan

        
On Tue, May 1, 2018 at 4:33 PM, William Dunlap <wdunlap at tibco.com> wrote:

        

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

  
  


  


      

    

    

      
      

        


  

        

      Eivind K. Dovik
    

    

      
      #
    

  


  

      
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:

        

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Martin Maechler
    

    

      
      #
    

  


  

          

      
      
      
    

        
> 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

yes, indeed,  or -- even nicer for a time series:
using  'type = "c"'  which many people don't know / have forgotten about:

ttt <- ts(rpois(12, lambda = 8), start = c(2000, 1), freq = 4)
plot  (ttt, type = "c")
points(ttt, col = ifelse(ttt < 8, "black", "red"))

Martin Maechler

        
> 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 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.
    >>>> 
    >>> 
    >>> 
    >> 
    >> [[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.
    >> 

    > ______________________________________________
    > 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.