For the year from 2022-01-01 to 2022-12-31, I computed the sunrise and sunset times for Reston, Virginia, USA. I am seeking the syntax to direct R to read in these dates and times, and then graphical plot the sunrise and sunset times for each day in the year 2022. How do I tell R that I store the Sunrise Date and Time like this? YYYY-mm-dd HH:MM:SS 2022-01-01 7:28:10 2022-01-02 7:28:17 Greg Coats
Date and Time
5 messages · Gregory Coats, Jeff Newmiller, @vi@e@gross m@iii@g oii gm@ii@com +2 more
Maybe this [1] will help? Or just read ?strptime... You can also calculate sunrise/sunset (crepuscule) using maptools, but you need to be careful with timezones. [1] https://jdnewmil.github.io/time-2018-10/MoreDatetimeHowto.html
On July 17, 2022 8:47:19 PM PDT, Gregory Coats via R-help <r-help at r-project.org> wrote:
For the year from 2022-01-01 to 2022-12-31, I computed the sunrise and sunset times for Reston, Virginia, USA. I am seeking the syntax to direct R to read in these dates and times, and then graphical plot the sunrise and sunset times for each day in the year 2022. How do I tell R that I store the Sunrise Date and Time like this? YYYY-mm-dd HH:MM:SS 2022-01-01 7:28:10 2022-01-02 7:28:17 Greg Coats [[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.
Sent from my phone. Please excuse my brevity.
Greg,
Strictly speaking, you don't tell R and keep it a secret!
More seriously, are you reading in your data as text of a sort in a file, or
as part of a CSV file or Spreadsheet or what?
What do you plan on graphing the data with? It sounds like you likely need
to make a data.frame or tibble that has at least two columns with one being
a DATE of some kind so you can plot the date, versus another being a kind of
TIME.
There are many ways to record time in R as dates or date+time or duration
and you need to pick some that will work with the ploting program such as
base R or ggplot.
You say your dates look like this:
YYYY-mm-dd HH:MM:SS
2022-01-01 7:28:10
It is fairly easy to split that into a date STRING in one variable and a
time string in another.
Then you need to convert a vector of each (perhaps in a data.frame) into
some objects of a type that hold the data properly. You can use standard R
functions or various packages. If your format is already compatible, so
this:
date_part <- as.Date("2022-01-01")
You can see if it worked by adding 1 day to it:
date_part+1
[1] "2022-01-02" If your format is something specific, you can pass templates to guide some function in parsing it. Similarly you can find R functions that store a time and of course more advanced ones that store both in several ways. But for graphing what you want as a sort of sinusoidal function, you would need to extract the time and date from it. If you search online, you can find lots of tutorials and discussions as this is a very common thing. I don't mean sunsets, but measurements versus dates. -----Original Message----- From: R-help <r-help-bounces at r-project.org> On Behalf Of Gregory Coats via R-help Sent: Sunday, July 17, 2022 11:47 PM To: Gregory Coats via R-help <r-help at r-project.org> Subject: [R] Date and Time For the year from 2022-01-01 to 2022-12-31, I computed the sunrise and sunset times for Reston, Virginia, USA. I am seeking the syntax to direct R to read in these dates and times, and then graphical plot the sunrise and sunset times for each day in the year 2022. How do I tell R that I store the Sunrise Date and Time like this? YYYY-mm-dd HH:MM:SS 2022-01-01 7:28:10 2022-01-02 7:28:17 Greg Coats
On 7/17/2022 8:47 PM, Gregory Coats via R-help wrote:
For the year from 2022-01-01 to 2022-12-31, I computed the sunrise and sunset times for Reston, Virginia, USA. I am seeking the syntax to direct R to read in these dates and times, and then graphical plot the sunrise and sunset times for each day in the year 2022. How do I tell R that I store the Sunrise Date and Time like this? YYYY-mm-dd HH:MM:SS 2022-01-01 7:28:10 2022-01-02 7:28:17 Greg Coats [[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.
Here is one way using the strptime function, > in_dt_str <- '2022-01-01? 7:28:10' > dt <- strptime(in_dt_str,'%Y-%m-%d %H:%M:%S') if the date and time are stored in different variables then paste them together before converting > in_dt <- '2022-01-01' > in_tm <- '7:28:10' > dtm <- strptime(paste(in_dt, in_tm, sep=' '),'%Y-%m-%d %H:%M:%S') Hope this is helpful, Dan -- Daniel Nordlund Port Townsend, WA USA
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An alternative is the lubridate() package if you use tidyverse. Check the data for daylight savings time. Twice per year Virginia changes time where in the Fall clocks are shifted back an hour and in the Spring they jump forwards an hour. -----Original Message----- From: R-help <r-help-bounces at r-project.org> On Behalf Of Jeff Newmiller Sent: Monday, July 18, 2022 12:35 AM To: Greg Comcast Coats <gregcoats at me.com>; Gregory Coats via R-help <r-help at r-project.org> Subject: Re: [R] Date and Time [External Email] Maybe this [1] will help? Or just read ?strptime... You can also calculate sunrise/sunset (crepuscule) using maptools, but you need to be careful with timezones. [1] https://urldefense.proofpoint.com/v2/url?u=https-3A__jdnewmil.github.io_time-2D2018-2D10_MoreDatetimeHowto.html&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRzsn7AkP-g&m=Eym42IWzdKGREg7m9o0QowA8hP-DgHTrlZwDfW5no2rP6ND_uFJKHbJ_Dj3XGPiP&s=O5VruA8vvqyhQngUZ3fuZtnZiYIm9XEscpzxcGKX9AQ&e=
On July 17, 2022 8:47:19 PM PDT, Gregory Coats via R-help <r-help at r-project.org> wrote:
For the year from 2022-01-01 to 2022-12-31, I computed the sunrise and sunset times for Reston, Virginia, USA. I am seeking the syntax to direct R to read in these dates and times, and then graphical plot the sunrise and sunset times for each day in the year 2022. How do I tell R that I store the Sunrise Date and Time like this?
YYYY-mm-dd HH:MM:SS
2022-01-01 7:28:10
2022-01-02 7:28:17
Greg Coats
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailm an_listinfo_r-2Dhelp&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRz sn7AkP-g&m=Eym42IWzdKGREg7m9o0QowA8hP-DgHTrlZwDfW5no2rP6ND_uFJKHbJ_Dj3X GPiP&s=7XAM9jGAgm-2KbQG5x3oKKxrvNESM5DAvl_O3YxSU3Y&e= PLEASE do read the posting guide https://urldefense.proofpoint.com/v2/url?u=http-3A__www.R-2Dproject.org _posting-2Dguide.html&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsR zsn7AkP-g&m=Eym42IWzdKGREg7m9o0QowA8hP-DgHTrlZwDfW5no2rP6ND_uFJKHbJ_Dj3 XGPiP&s=MwaLmYJXfAwQDsHSzq8Atm-QC2YpJYie_L5oNkAJiVg&e= and provide commented, minimal, self-contained, reproducible code.
-- Sent from my phone. Please excuse my brevity. ______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://urldefense.proofpoint.com/v2/url?u=https-3A__stat.ethz.ch_mailman_listinfo_r-2Dhelp&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRzsn7AkP-g&m=Eym42IWzdKGREg7m9o0QowA8hP-DgHTrlZwDfW5no2rP6ND_uFJKHbJ_Dj3XGPiP&s=7XAM9jGAgm-2KbQG5x3oKKxrvNESM5DAvl_O3YxSU3Y&e= PLEASE do read the posting guide https://urldefense.proofpoint.com/v2/url?u=http-3A__www.R-2Dproject.org_posting-2Dguide.html&d=DwICAg&c=sJ6xIWYx-zLMB3EPkvcnVg&r=9PEhQh2kVeAsRzsn7AkP-g&m=Eym42IWzdKGREg7m9o0QowA8hP-DgHTrlZwDfW5no2rP6ND_uFJKHbJ_Dj3XGPiP&s=MwaLmYJXfAwQDsHSzq8Atm-QC2YpJYie_L5oNkAJiVg&e= and provide commented, minimal, self-contained, reproducible code.