Hello,I am trying to read a data frame column named DateTimeStamp. The time is
in GMT in this format: 1/4/2013 23:30
require(xlsx)
df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1")
It's good to that line. But these three lines, which makes the dataframe,
converts the column's values to NA:df2_TZ$DateTimeStamp =
as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S",
tz="GMT")
and...?df2_TZ$DateTimeStamp = as.POSIXct(as.character(df2_TZ$DateTimeStamp),
format = "%m/%d/%Y %H:%M:%S")
and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format =
"%m/%d/%Y %H:%M:%S")
This line returns and error...df2_TZ$DateTimeStamp =
as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y
%H:%M:%S")
"Error in charToDate(x) :?? character string is not in a standard
unambiguous format"
Additionally, I need to convert from GMT to North American time zones, and I
think the advice on this page would be good for
that:?http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html
My ultimate goal is to write an R program that finds data in another variable in
df2_TZ that corresponds to a date and time that match up with the date and time
in another data frame. For now, any help reading the column would be much
appreciated.
Thank You,Doug
[[alternative HTML version deleted]]
You are being rather scattershot in your explanation, so I suspect you are not being systematic in your troubleshooting. Use the str function to examine the data column after you pull it in from excel. It may be numeric, factor, or character, and the approach depends on which that function returns. -- Sent from my phone. Please excuse my brevity. On February 18, 2016 1:12:40 PM PST, D Wolf via R-help <r-help at r-project.org> wrote:>Hello,I am trying to read a data frame column named DateTimeStamp. The >time is in GMT in this format: 1/4/2013 23:30 >require(xlsx) >df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1") > >It's good to that line. But these three lines, which makes the >dataframe, converts the column's values to NA:df2_TZ$DateTimeStamp >as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S", tz="GMT") > >and...?df2_TZ$DateTimeStamp >as.POSIXct(as.character(df2_TZ$DateTimeStamp), format = "%m/%d/%Y >%H:%M:%S") > >and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format >"%m/%d/%Y %H:%M:%S") > >This line returns and error...df2_TZ$DateTimeStamp >as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y %H:%M:%S") >"Error in charToDate(x) :?? character string is not in a standard >unambiguous format" >Additionally, I need to convert from GMT to North American time zones, >and I think the advice on this page would be good for >that:?http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html >My ultimate goal is to write an R program that finds data in another >variable in df2_TZ that corresponds to a date and time that match up >with the date and time in another data frame. For now, any help reading >the column would be much appreciated. >Thank You,Doug > [[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.[[alternative HTML version deleted]]
Hi Doug, For one thing, you may be using the wrong format. Your example format has no seconds field. The other thing to watch is whether the data are in %m/%d/%Y or %d/%m/%Y date format. If the latter, you would probably get that error on dates like 19/02/2016. Jim On Fri, Feb 19, 2016 at 8:12 AM, D Wolf via R-help <r-help at r-project.org> wrote:> Hello,I am trying to read a data frame column named DateTimeStamp. The > time is in GMT in this format: 1/4/2013 23:30 > require(xlsx) > df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1") > > It's good to that line. But these three lines, which makes the dataframe, > converts the column's values to NA:df2_TZ$DateTimeStamp > as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S", tz="GMT") > > and... df2_TZ$DateTimeStamp > as.POSIXct(as.character(df2_TZ$DateTimeStamp), format = "%m/%d/%Y %H:%M:%S") > > and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format > "%m/%d/%Y %H:%M:%S") > > This line returns and error...df2_TZ$DateTimeStamp > as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y %H:%M:%S") > "Error in charToDate(x) : character string is not in a standard > unambiguous format" > Additionally, I need to convert from GMT to North American time zones, and > I think the advice on this page would be good for that: > http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html > My ultimate goal is to write an R program that finds data in another > variable in df2_TZ that corresponds to a date and time that match up with > the date and time in another data frame. For now, any help reading the > column would be much appreciated. > Thank You,Doug > [[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.[[alternative HTML version deleted]]
Hello Jim,
I ran str() on the vector and it returned
character:str("DF_exp.xlsx")?chr "DF_exp.xlsx"
I tried?df2_TZ$DateTimeStamp <-
strptime(as.Date(as.character(df2_TZ$DateTimeStamp, format = "%m/%d/%Y
%H:%M", tz = "GMT"))), which produced an error:?Error in
charToDate(x) :?? character string is not in a standard unambiguous formatIn
Excel, the column is formatted to m/d/yyyy h:mm
Removing %S from these linesdf2_TZ$DateTimeStamp =
as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M",
tz="GMT")?df2_TZ$DateTimeStamp =
as.POSIXct(as.character(df2_TZ$DateTimeStamp), format = "%m/%d/%Y
%H:%M")
made the column NA
Thank You,Doug Wolfinger
On Friday, February 19, 2016 1:35 AM, Jim Lemon <drjimlemon at
gmail.com> wrote:
Hi Doug,For one thing, you may be using the wrong format. Your example format
has no seconds field. The other thing to watch is whether the data are in
%m/%d/%Y or %d/%m/%Y date format. If the latter, you would probably get that
error on dates like 19/02/2016.
Jim
On Fri, Feb 19, 2016 at 8:12 AM, D Wolf via R-help <r-help at
r-project.org> wrote:
Hello,I am trying to read a data frame column named DateTimeStamp. The time is
in GMT in this format: 1/4/2013 23:30
require(xlsx)
df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1")
It's good to that line. But these three lines, which makes the dataframe,
converts the column's values to NA:df2_TZ$DateTimeStamp =
as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S",
tz="GMT")
and...?df2_TZ$DateTimeStamp = as.POSIXct(as.character(df2_TZ$DateTimeStamp),
format = "%m/%d/%Y %H:%M:%S")
and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format =
"%m/%d/%Y %H:%M:%S")
This line returns and error...df2_TZ$DateTimeStamp =
as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y
%H:%M:%S")
"Error in charToDate(x) :?? character string is not in a standard
unambiguous format"
Additionally, I need to convert from GMT to North American time zones, and I
think the advice on this page would be good for
that:?http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html
My ultimate goal is to write an R program that finds data in another variable in
df2_TZ that corresponds to a date and time that match up with the date and time
in another data frame. For now, any help reading the column would be much
appreciated.
Thank You,Doug
? ? ? ? [[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.
[[alternative HTML version deleted]]
This is a mailing list. I don't know how you are interacting with it... using a website rather than an email program can lead to some confusion since there can be many ways to accomplish the task of interacting with the mailing list. My email program has a "reply-all" button when I am looking at an email. It also has an option to write the email in plain text, which often prevents the message from getting corrupted (recipient not seeing what you sent to the list). Using the str function on a literal string (the name of a file) will indeed tell you that you gave it a character string. Specifying a column in your data might tell you something more interesting... e.g. str( df2_TZ$DateTimeStamp ) If that says you have character data then Jim Lemon's suggestion would be a good next thing to look at. If it is factor data then you should use the as.character function on the data column and then follow Jim's suggestion. If it is numeric then you probably need to convert it using an appropriate origin (e.g. as described at [1] or [2]). I have had best luck setting the default timezone string when converting to POSIXt types... e.g. # specify timezone assumed by input data Sys.setenv( TZ="GMT" ) testdtm <- as.POSIXct( "1/1/2016 00:00", format = "%m/%d/%Y %H:%M" ) # inspect the result testdtm str( testdtm ) # view data from a different timezone Sys.setenv( TZ="Etc/GMT+8" ) # no change to the underlying data, but it prints out differently now because the tz attribute is "" which implies using the default TZ testdtm [1] http://blog.mollietaylor.com/2013/08/date-formats-in-r.html [2] https://www.r-project.org/doc/Rnews/Rnews_2004-1.pdf -- Sent from my phone. Please excuse my brevity. On February 19, 2016 7:48:31 AM PST, D Wolf <doug45290 at yahoo.com> wrote:>Hello Jeff, >I ran str() on the vector and it returned character.> >str("DF_exp.xlsx")?chr "DF_exp.xlsx" >This is my first thread on this forum, and I'm not sure how to reply to >the thread instead of just sending the reply to your email account; I >don't see a 'reply' link in the thread.I've read this page and I don't >think it advises on how to reply in the thread:?R: Posting Guide: How >to ask good questions that prompt useful answers > >| ? | >| ? | | ? | ? | ? | ? | ? | >| R: Posting Guide: How to ask good questions that prompt ...Posting >Guide: How to ask good questions that prompt useful answers This guide >is intended to help you get the most out of the R mailing lists, and to >avoid embarra... | >| | >| View on www.r-project.org | Preview by Yahoo | >| | >| ? | > > >Thank You,Doug Wolfinger > > >On Friday, February 19, 2016 12:51 AM, Jeff Newmiller ><jdnewmil at dcn.davis.ca.us> wrote: > > >You are being rather scattershot in your explanation, so I suspect you >are not being systematic in your troubleshooting. Use the str function >to examine the data column after you pull it in from excel. It may be >numeric, factor, or character, and the approach depends on which that >function returns. >-- >Sent from my phone. Please excuse my brevity. > >On February 18, 2016 1:12:40 PM PST, D Wolf via R-help ><r-help at r-project.org> wrote: >Hello,I am trying to read a data frame column named DateTimeStamp. The >time is in GMT in this format: 1/4/2013 23:30 >require(xlsx) >df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1") > >It's good to that line. But these three lines, which makes the >dataframe, converts the column's values to NA:df2_TZ$DateTimeStamp >as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S", tz="GMT") > >and...?df2_TZ$DateTimeStamp >as.POSIXct(as.character(df2_TZ$DateTimeStamp), format = "%m/%d/%Y >%H:%M:%S") > >and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format >"%m/%d/%Y %H:%M:%S") > >This line returns and error...df2_TZ$DateTimeStamp >as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y %H:%M:%S") >"Error in charToDate(x) :?? character string is not in a standard >unambiguous format" >Additionally, I need to convert from GMT to North American time zones, >and I think the advice on this page would >be good for >that:?http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html >My ultimate goal is to write an R program that finds data in another >variable in df2_TZ that corresponds to a date and time that match up >with the date and time in another data frame. For now, any help reading >the column would be much appreciated. >Thank You,Doug > [[alternative HTML version deleted]] > > >R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code.[[alternative HTML version deleted]]
Hello Everyone,?
The column begins populated with integers as so:1/1/2013 0:00 in the spreadsheet
equals 41257 in R's dataframe1/1/2013 0:15 in the spreadsheet equals
41257.010416666664 in R's dataframe...41257 must be in minutes since
1440min/day * .010416666664 day = 15 minutes. 41257 minutes is about 29 days:
41257 min / 1440 min/day = 28.65 days. So I don't know why the dataframe is
showing 41257 for 1/12013 0:00.?
Oddly, R sees the vector as NULL despite the fact it has integers in each record
in the column:data_type = str(df2_TZ$DateTimeStamp) produces a NULL (empty)
variable.?
I tried:
df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName =
"Sheet1")Sys.setenv(TZ = "GMT")testdtm <-
as.POSIXct(df2_TZ$DateTimeStamp, format = "%m/%d/%Y %H:%M")# Inspect
the resulttestdtmstr(testdtm)
testdtm is a vector filled with NA values, which figures since DateTimeStamp is
NULL.?
I noticed in the table on page 32 of the R Help Desk pdf you linked to that
dp-as.POSIXct(format(dp, tz="GMT")) is the only option listed for time
zone difference. So I tried:df2_TZ = read.xlsx2("DF_exp.xlsx",
sheetName = "Sheet1")df2_TZ_seq <- as.POSIXct(format(dt2_TZ,
tz="GMT"))
and got:?Error in format(dt2_TZ, tz = "GMT") : object 'dt2_TZ'
not found
Is the vector neither character nor factor, since it's NULL? Where do I go
from here??
Thank You,Doug
Hi Doug,What you have done is to ask whether the character string
"DF_exp.xlsx" is a character string. I think Yogi Berra, were he still
around, could have told you that. What will give you some useful information is:
str(DF_exp.xlsx)
which asks for information about the object, not its name.
Jim
On Friday, February 19, 2016 12:41 PM, Jeff Newmiller <jdnewmil at
dcn.davis.ca.us> wrote:
This is a mailing list. I don't know how you are interacting with it...
using a website rather than an email program can lead to some confusion since
there can be many ways to accomplish the task of interacting with the mailing
list. My email program has a "reply-all" button when I am looking at
an email. It also has an option to write the email in plain text, which often
prevents the message from getting corrupted (recipient not seeing what you sent
to the list).
Using the str function on a literal string (the name of a file) will indeed tell
you that you gave it a character string. Specifying a column in your data might
tell you something more interesting... e.g.
str( df2_TZ$DateTimeStamp )
If that says you have character data then Jim Lemon's suggestion would be a
good next thing to look at. If it is factor data then you should use the
as.character function on the data column and then follow Jim's suggestion.
If it is numeric then you probably need to convert it using an appropriate
origin (e.g. as described at [1] or [2]).
I have had best luck setting the default timezone string when converting to
POSIXt types... e.g.
# specify timezone assumed by input data
Sys.setenv( TZ="GMT" )
testdtm <- as.POSIXct( "1/1/2016 00:00", format = "%m/%d/%Y
%H:%M" )
# inspect the result
testdtm
str( testdtm )
# view data from a different timezone
Sys.setenv( TZ="Etc/GMT+8" )
# no change to the underlying data, but it prints out differently now because
the tz attribute is "" which implies using the default TZ
testdtm
[1] http://blog.mollietaylor.com/2013/08/date-formats-in-r.html
[2] https://www.r-project.org/doc/Rnews/Rnews_2004-1.pdf
--
Sent from my phone. Please excuse my brevity.
On February 19, 2016 7:48:31 AM PST, D Wolf <doug45290 at yahoo.com>
wrote:
Hello Jeff,
I ran str() on the vector and it returned character.>
str("DF_exp.xlsx")?chr "DF_exp.xlsx"
This is my first thread on this forum, and I'm not sure how to reply to the
thread instead of just sending the reply to your email account; I don't see
a 'reply' link in the thread.I've read this page and I don't
think it advises on how to reply in the thread:?R: Posting Guide: How to ask
good questions that prompt useful answers
| ? |
| ? | | ? | ? | ? | ? | ? |
| R: Posting Guide: How to ask good questions that prompt ...Posting Guide: How
to ask good questions that prompt useful answers This guide is intended to help
you get the most out of the R mailing lists, and to avoid embarra... |
| |
| View on www.r-project.org | Preview by Yahoo |
| |
| ? |
Thank You,Doug Wolfinger
On Friday, February 19, 2016 12:51 AM, Jeff Newmiller <jdnewmil at
dcn.davis.ca.us> wrote:
You are being rather scattershot in your explanation, so I suspect you are not
being systematic in your troubleshooting. Use the str function to examine the
data column after you pull it in from excel. It may be numeric, factor, or
character, and the approach depends on which that function returns.
--
Sent from my phone. Please excuse my brevity.
On February 18, 2016 1:12:40 PM PST, D Wolf via R-help <r-help at
r-project.org> wrote:
Hello,I am trying to read a data frame column named DateTimeStamp. The time is
in GMT in this format: 1/4/2013 23:30
require(xlsx)
df2_TZ = read.xlsx2("DF_exp.xlsx", sheetName = "Sheet1")
It's good to that line. But these three lines, which makes the dataframe,
converts the column's values to NA:df2_TZ$DateTimeStamp =
as.POSIXct(df2_TZ$DateTimeStamp, format="%m/%d/%Y %H:%M:%S",
tz="GMT")
and...?df2_TZ$DateTimeStamp = as.POSIXct(as.character(df2_TZ$DateTimeStamp),
format = "%m/%d/%Y %H:%M:%S")
and...df2_TZ$DateTimeStamp = as.Date(df2_TZ$DateTimeStamp, format =
"%m/%d/%Y %H:%M:%S")
This line returns and error...df2_TZ$DateTimeStamp =
as.POSIXct(as.Date(df2_TZ$DateTimeStamp), format = "%m/%d/%Y
%H:%M:%S")
"Error in charToDate(x) :??
character string is not in a standard unambiguous format"
Additionally, I need to convert from GMT to North American time zones, and I
think the advice on this page would
be good for
that:?http://blog.revolutionanalytics.com/2009/06/converting-time-zones.html
My ultimate goal is to write an R program that finds data in another variable in
df2_TZ that corresponds to a date and time that match up with the date and time
in another data frame. For now, any help reading the column would be much
appreciated.
Thank You,Doug
[[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.
[[alternative HTML version deleted]]