Problems Dating....

[StatBat2]

I'm trying to convert a column in a data frame with dates from a
"Factor" type to a "Date Object" but I am encountering and error. (I am
having trouble plotting an x,y scatter and I suspect it's something with
my data format). I have a table with two columns and 8,000 rows.

> dsort=read.delim("C:\\Documents and Settings\\E066582\\My
Documents\\R\\R-2.13.0\\bin\\dsort.txt")

 

"dsort"                                                #name of
data.frame

> colnames(dsort)[1]                     #name of column 1

[1] "Date"

> colnames(dsort)[2]                     #name of column 2

[1] "Qty"

> class(dsort$Date)                         #checked data type of column
"Date" and it came back as a factor

[1] "factor"

> Date2=as.Date(dsort$Date)    #attempt at changing the data type from a
factor to a date object (see error below).

Error in charToDate(x) :

  character string is not in a standard unambiguous format

 

Dates in my table are listed in "3/4/2007" format.

StatBat2

 


        [[alternative HTML version deleted]]

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[Stephan Kolassa]

Hi Nat,

I guess something like
as.Date(as.character("3/4/2007"),format="%d/%m/%Y")
should work - as.character() coerces the factors to characters, which
the as.Date() function can work with, given the right format argument.

HTH
Stephan


Am 01.06.2011 22:59, schrieb Struckmeier, Nathanael:

> I'm trying to convert a column in a data frame with dates from a
> "Factor" type to a "Date Object" but I am encountering and error. (I am
> having trouble plotting an x,y scatter and I suspect it's something with
> my data format). I have a table with two columns and 8,000 rows.
>
>> dsort=read.delim("C:\\Documents and Settings\\E066582\\My
> Documents\\R\\R-2.13.0\\bin\\dsort.txt")
>
>
>
> "dsort"                                                #name of
> data.frame
>
>> colnames(dsort)[1]                     #name of column 1
>
> [1] "Date"
>
>> colnames(dsort)[2]                     #name of column 2
>
> [1] "Qty"
>
>> class(dsort$Date)                         #checked data type of column
> "Date" and it came back as a factor
>
> [1] "factor"
>
>> Date2=as.Date(dsort$Date)    #attempt at changing the data type from a
> factor to a date object (see error below).
>
> Error in charToDate(x) :
>
>    character string is not in a standard unambiguous format
>
>
>
> Dates in my table are listed in "3/4/2007" format.
>
> StatBat2
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> 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.
>

______________________________________________
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and provide commented, minimal, self-contained, reproducible code.

[Marc Schwartz-3]

On Jun 1, 2011, at 3:59 PM, Struckmeier, Nathanael wrote:

> I'm trying to convert a column in a data frame with dates from a
> "Factor" type to a "Date Object" but I am encountering and error. (I am
> having trouble plotting an x,y scatter and I suspect it's something with
> my data format). I have a table with two columns and 8,000 rows.
>
>> dsort=read.delim("C:\\Documents and Settings\\E066582\\My
> Documents\\R\\R-2.13.0\\bin\\dsort.txt")
>
>
>
> "dsort"                                                #name of
> data.frame
>
>> colnames(dsort)[1]                     #name of column 1
>
> [1] "Date"
>
>> colnames(dsort)[2]                     #name of column 2
>
> [1] "Qty"
>
>> class(dsort$Date)                         #checked data type of column
> "Date" and it came back as a factor
>
> [1] "factor"
>
>> Date2=as.Date(dsort$Date)    #attempt at changing the data type from a
> factor to a date object (see error below).
>
> Error in charToDate(x) :
>
>  character string is not in a standard unambiguous format
>
>
>
> Dates in my table are listed in "3/4/2007" format.
>
> StatBat2

After seeing your subject line and your e-mail address, I was going to suggest a dozen roses and some Moose Munch...  ;-)

When you convert a character/factor to a Date, you need to specify the format of the object to be converted:

> as.Date("3/4/2007", format = "%m/%d/%Y")
[1] "2007-03-04"

See ?as.Date and ?strptime for more information and format specifications.

HTH,

Marc Schwartz

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[StatBat2]

I'll give this a try and mess with what format to convert it to. Thanks
again!




-----Original Message-----
From: Stephan Kolassa [mailto:[hidden email]]
Sent: Wednesday, June 01, 2011 2:10 PM
To: Struckmeier, Nathanael
Cc: [hidden email]
Subject: Re: [R] Problems Dating....

Hi Nat,

I guess something like
as.Date(as.character("3/4/2007"),format="%d/%m/%Y")
should work - as.character() coerces the factors to characters, which
the as.Date() function can work with, given the right format argument.

HTH
Stephan


Am 01.06.2011 22:59, schrieb Struckmeier, Nathanael:
> I'm trying to convert a column in a data frame with dates from a
> "Factor" type to a "Date Object" but I am encountering and error. (I
am
> having trouble plotting an x,y scatter and I suspect it's something
with

> my data format). I have a table with two columns and 8,000 rows.
>
>> dsort=read.delim("C:\\Documents and Settings\\E066582\\My
> Documents\\R\\R-2.13.0\\bin\\dsort.txt")
>
>
>
> "dsort"                                                #name of
> data.frame
>
>> colnames(dsort)[1]                     #name of column 1
>
> [1] "Date"
>
>> colnames(dsort)[2]                     #name of column 2
>
> [1] "Qty"
>
>> class(dsort$Date)                         #checked data type of

column
> "Date" and it came back as a factor
>
> [1] "factor"
>
>> Date2=as.Date(dsort$Date)    #attempt at changing the data type from
a

> factor to a date object (see error below).
>
> Error in charToDate(x) :
>
>    character string is not in a standard unambiguous format
>
>
>
> Dates in my table are listed in "3/4/2007" format.
>
> StatBat2
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] mailing list
> 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.
>

______________________________________________
[hidden email] mailing list
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.

[David Winsemius]

On Jun 1, 2011, at 5:14 PM, Struckmeier, Nathanael wrote:

> I'll give this a try and mess with what format to convert it to.  
> Thanks
> again!
>
You need to decide whether to use "%d/%m/%Y" or "%m/%d/%" , since the  
information you provided so far leaves that undetermined.

--
David.

>
>
> Hi Nat,
>
> I guess something like
> as.Date(as.character("3/4/2007"),format="%d/%m/%Y")
> should work - as.character() coerces the factors to characters, which
> the as.Date() function can work with, given the right format argument.
>
> HTH
> Stephan
>
>
> Am 01.06.2011 22:59, schrieb Struckmeier, Nathanael:
>> I'm trying to convert a column in a data frame with dates from a
>> "Factor" type to a "Date Object" but I am encountering and error. (I
> am
>> having trouble plotting an x,y scatter and I suspect it's something
> with
>> my data format). I have a table with two columns and 8,000 rows.
>>
>>> dsort=read.delim("C:\\Documents and Settings\\E066582\\My
>> Documents\\R\\R-2.13.0\\bin\\dsort.txt")
>>
>>
>>
>> "dsort"                                                #name of
>> data.frame
>>
>>> colnames(dsort)[1]                     #name of column 1
>>
>> [1] "Date"
>>
>>> colnames(dsort)[2]                     #name of column 2
>>
>> [1] "Qty"
>>
>>> class(dsort$Date)                         #checked data type of
> column
>> "Date" and it came back as a factor
>>
>> [1] "factor"
>>
>>> Date2=as.Date(dsort$Date)    #attempt at changing the data type from
> a
>> factor to a date object (see error below).
>>
>> Error in charToDate(x) :
>>
>>   character string is not in a standard unambiguous format
>>
>>
>>
>> Dates in my table are listed in "3/4/2007" format.
>>
>> StatBat2
>>
>>
>>
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> [hidden email] mailing list
>> 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.
>>
>
> ______________________________________________
> [hidden email] mailing list
> 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.

David Winsemius, MD
West Hartford, CT

______________________________________________
[hidden email] mailing list
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.