Dear Greg,
There is no variable named Y_Var in your data set. I suspect that it's
intended to be a generic specification in the recipe you were apparently
given. In fact, there appears to be only one variable in myDat and
that's datetime. What is it that you're trying to do?
A more general comment: If I'm correct and you're just following a
recipe, that's a recipe for problems. You'd probably be more successful
if you tried to learn how ggplot(), etc., work. My apologies if I'm
misinterpreting the source of your difficulties.
I hope this helps,
John
John Fox, Professor Emeritus
McMaster University
Hamilton, Ontario, Canada
web: https://socialsciences.mcmaster.ca/jfox/
On 2021-03-16 12:21 p.m., Gregory Coats via R-help wrote:
Sarah, Thank you. Yes, now as.POSIXct works.
But the ggplot command I was told to use yields an Error message, and there is
no output plot.
Please help me. Greg
library(ggplot2)
myDat <- read.table(text =
+ "datetime
+ 2021-03-11 10:00:00
+ 2021-03-11 14:17:00
+ 2021-03-12 05:16:46
+ 2021-03-12 09:17:02
+ 2021-03-12 13:31:43
+ 2021-03-12 22:00:32
+ 2021-03-13 09:21:43",
+ sep = ",", header = TRUE)
head(myDat)
datetime
1 2021-03-11 10:00:00
2 2021-03-11 14:17
3 2021-03-12 05:16:46
4 2021-03-12 09:17:02
5 2021-03-12 13:31:43
6 2021-03-12 22:00:32
myDat$datetime <- as.POSIXct(myDat$datetime, tz = "", format ="%Y-%M-%d
%H:%M:%OS”)
ggplot(myDat, aes(x=datetime, y = Y_Var)) + geom_point()
Error in FUN(X[[i]], ...) : object 'Y_Var' not found
On Mar 16, 2021, at 9:36 AM, Sarah Goslee <sarah.gos...@gmail.com> wrote:
Hi,
It doesn't have anything to do with having a Mac - you have POSIX.
It's because something is wrong with your data import. Looking at the
head() output you provided, it looks like your data file does NOT have
a header, because there's no datetime column, and the column name is
actually X2021.03.11.10.00.0
So you specified a nonexistent column, and got a zero-length answer.
With correct specification, the as.POSIXct function works as expected on Mac:
myDat <- read.table(text =
"datetime
2021-03-11 10:00:00
2021-03-11 14:17:00
2021-03-12 05:16:46
2021-03-12 09:17:02
2021-03-12 13:31:43
2021-03-12 22:00:32
2021-03-13 09:21:43",
sep = ",", header = TRUE)
myDat$datetime <- as.POSIXct(myDat$datetime, tz = "", format =
"%Y-%M-%d %H:%M:%OS")
Sarah
On Tue, Mar 16, 2021 at 9:26 AM Gregory Coats via R-help
<r-help@r-project.org> wrote:
My computer is an Apple MacBook. I do not have POSIX.
The command
myDat$datetime <- as.POSIXct(myDat$datetime, tz = "", format = "%Y-%M-%d
%H:%M:%OS")
yields the error
Error in `$<-.data.frame`(`*tmp*`, datetime, value = numeric(0)) :
replacement has 0 rows, data has 13
Please advise, How to proceed?
Greg Coats
library(ggplot2)
# Read a txt file on the Desktop, named "myDat.txt"
myDat <- read.delim("~/Desktop/myDat.txt", header = TRUE, sep = ",")
head(myDat)
X2021.03.11.10.00.00
1 2021-03-11 14:17:00
2 2021-03-12 05:16:46
3 2021-03-12 09:17:02
4 2021-03-12 13:31:43
5 2021-03-12 22:00:32
6 2021-03-13 09:21:43
# convert data to date time object
myDat$datetime <- as.POSIXct(myDat$datetime, tz = "", format = "%Y-%M-%d
%H:%M:%OS")
Error in `$<-.data.frame`(`*tmp*`, datetime, value = numeric(0)) :
replacement has 0 rows, data has 13
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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--
Sarah Goslee (she/her)
http://www.numberwright.com
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______________________________________________
R-help@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@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.
