[R] How to specify year-month-day for a plot

[Jeff Newmiller]

Bill pointed out some errors in your code but you keep making the claim that YYYY-MM-DD is not recognized and I just want to make it completely clear that that is the default format for dates in R as it is an ISO standard. So focus on other issues until you get it working... this format is definitely not your problem.

On December 13, 2020 5:34:45 PM PST, Gregory Coats via R-help <r-help using r-project.org> wrote:
>Hi Jim,
>Thank you VERY much!
>In what I tried, my values for the vertical Y were automatically
>understood by R.
>But it appears that the string yyyy-mm-dd was NOT recognized by R as a
>date for the X axis, and gave a red error message.
>My values for Year-Month-Day were NOT understood by R.
>Is there a convenient way to tell R to interpret “2020-12-13” as a
>date?
>
>data <- data.frame(
>day = as.Date("2020-02-15", "2020-03-10", "2020-05-04", "2020-06-21",
>"2020-08-01", "2020-08-27", "2020-09-28", "2020-11-09", "2020-12-11")
>value = (15.973, 18.832, 17.392, 14.774, 19.248, 14.913, 15.226,
>14.338, 18.777, 19.652))
>p <- ggplot(data, aes(x=day, y=value))
>  geom_line()
>  xlab("X Label")
>p
>Error: unexpected symbol in:
>"  day = as.Date("2020-02-15", "2020-03-10", "2020-05-04",
>"2020-06-21", "2020-08-01", "2020-08-27", "2020-09-28", "2020-11-09",
>"2020-12-11")
>  value"
>
>Greg Coats
>gregcoats using me.com
>Reston, Virginia USA
>
>> On Dec 13, 2020, at 5:42 PM, Jim Lemon <drjimlemon using gmail.com> wrote:
>> 
>> Hi Gregory,
>> Here's a start:
>> 
>> gcdf<-read.table(text="2020-01-05 15.973
>> 2020-02-15 18.832
>> 2020-03-10 17.392
>> 2020-05-04 14.774
>> 2020-06-21 19.248
>> 2020-08-01 14.913
>> 2020-08-27 15.226
>> 2020-09-28 14.338
>> 2020-11-09 18.777
>> 2020-12-11 19.652",
>> header=TRUE,stringsAsFactors=FALSE,
>> col.names=c("date","gallons"))
>> gcdf$date<-as.Date(gcdf$date,"%Y-%m-%d")
>> plot(gcdf$date,gcdf$gallons,main="Gallons by date",
>> xlab="Date",ylab="Gallons")
>> 
>> Jim
>> 
>> On Mon, Dec 14, 2020 at 9:33 AM Gregory Coats via R-help
>> <r-help using r-project.org> wrote:
>>> 
>>> Starting with year-month-day, for the variable gallons, I can easily
>plot the variable gallons, while disregarding the date.
>>> gallons <- c (15.973, 18.832, 17.392, 14.774, 19.248, 14.913,
>15.226, 14.338, 18.777, 19.652)
>>> plot (gallons, type="l", xlab="X label", ylab="Y label", col="blue”)
>>> 
>>> How do I direct R to plot the variable gallons, at the appropriate,
>irregularly-spaced places on the X axis, while paying attention to the
>year-month-day?
>>> 
>>> format = "%Y-%m-%d”
>>> 2020-01-05 15.973
>>> 2020-02-15 18.832
>>> 2020-03-10 17.392
>>> 2020-05-04 14.774
>>> 2020-06-21 19.248
>>> 2020-08-01 14.913
>>> 2020-08-27 15.226
>>> 2020-09-28 14.338
>>> 2020-11-09 18.777
>>> 2020-12-11 19.652
>>>        [[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
>>> PLEASE do read the posting guide
>http://www.R-project.org/posting-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
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.

-- 
Sent from my phone. Please excuse my brevity.