[R] How do I "teach" R that columns 1, 2, and 3 are the Year-Month-Day

[Jeff Newmiller]

Reprex:

dta <- read.table( text =
"Yr  Mo Dy   Fuel
2021  7 25   50.45  
2021  8 27   61.48  
2021  9 26   59.07 
2021 11  4   55.40  
2021 11 22   30.63 
2021 11 26   41.35  
2021 12  6   32.81  
2022  1 14   49.86  
2022  4 29   62.99  
2022  6 11   89.37
", header=TRUE )
dta$Dtm <- with( dta, as.Date( ISOdate( Yr, Mo, Dy ) ) )
with( dta, plot( Dtm, Fuel ) )

The ISOdate function returns a POSIXct which includes time-of-day. Analyses that don't need time can instead rely on the Date type to avoid issues with timezones.

On June 14, 2022 6:08:17 PM PDT, Gregory Coats via R-help <r-help using r-project.org> wrote:
># Column 1 is the Year
># Column 2 is the Month
># Column 3 is the Day
># Column 4 is the Fuel
>Fuel <- c(50.45, 61.48, 59.07, 55.40, 30.63, 41.35, 32.81, 49.86, 62.99, 89.37)
>plot (Fuel)
>
>2021  7 25   50.45  
>2021  8 27   61.48  
>2021  9 26   59.07 
>2021 11  4   55.40  
>2021 11 22   30.63 
>2021 11 26   41.35  
>2021 12  6   32.81  
>2022  1 14   49.86  
>2022  4 29   62.99  
>2022  6 11   89.37  
>
>How do I "teach" R that columns 1, 2, and 3 are the Year-Month-Day?
>Greg Coats
>	[[alternative HTML version deleted]]
>
>______________________________________________
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>and provide commented, minimal, self-contained, reproducible code.

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