[R] re move row if the column "date_abandoned" has a date in it

frenchcr frenchcr at btinternet.com
Sun Nov 15 17:00:30 CET 2009



Yes they are not in date format, theyre just characters.

the earliest date is 16010000 i originally had one of  0101 00 00 (101 years
BC)...this was a software problem.

> table(nchar(new_data4$date_abandoned))

     2      8 
315732    263 

The 315732 are empty fields i thought.
The 263 are dates, i want to remove their rows.



David Winsemius wrote:
> 
> 
> On Nov 14, 2009, at 8:43 PM, frenchcr wrote:
> 
>>
>> sorry David,
>>
>> im really new to R (my first week) and appreciate your help. Also I  
>> dont
>> always know what info to give people on the forum (although im  
>> starting to
>> catch the drift).
>>
>> heres what i get...
>>
>> summary(new_data4$date_abandoned)
>> Min.        1st Qu.    Median     Mean      3rd Qu.      
>> Max.          NA's
>> 16010000 19980000 20010000 19930000 20040000  20090000   315732
> 
> So new_data4$data_abandoned is not of type "Date" and is instead a  
> character vector.
> 
> If you are resisting turning it into a date and want to work with  
> characters, you can, you just need to deal somehow with the items that  
> are not 8 characters wide. What does 315732 represent? How were we  
> supposed to interpret the starting "date" you gave of "01010000"?
> 
>  > nchar("1010000")
> [1] 7
> 
> What does table(nchar(new_data4$date_abandoned)) give you?
>>
>>> ls()
>> [1] "data"      "new_data"  "new_data2" "new_data3" "new_data4"
>>> small <- head(new_data4, 20)
>>> dump("small", 20)
>> Error in dump("small", 20) : cannot write to this connection
> 
> 
> Well, sorry, I meant to type dump("small", stdout())   ... As per the  
> Posting Guide.
> 
> -- 
> David.
>>
>> David Winsemius wrote:
>>>
>>>
>>> On Nov 14, 2009, at 5:24 PM, frenchcr wrote:
>>>
>>>>
>>>>
>>>> I tried the following but it does the opposite of what i want:
>>>>
>>>> new_data5 <- subset(new_data4, date_abandoned > "01010000")
>>>>
>>>> I want to remove the rows with dates and leave just the rows without
>>>> a date.
>>>>
>>>> This removes all the rows that dont have a date in the
>>>> date_abandoned column
>>>>
>>>> ...on a positive note, as i did this next...
>>>>
>>>> dim(new_data5)
>>>> [1] 263  80
>>>>
>>>> ....i now know that i have 263 dates in that column :)
>>>>
>>>> I want to remove the 263 rows with dates and leave just the rows
>>>> without a
>>>> date.
>>>
>>> Con=me on frenchcr. Stop making us guess. Give us enough information
>>> to work with. You asked for something which I construed as saying you
>>> wanted dates greater than the the first day of the year 101. You did
>>> not address this question.
>>>
>>> What do you get with str(new_data4) and
>>> summary(new_data4$date_abandoned) ? In order to know what sort of
>>> comparison to use we need to know what the data looks like.
>>>
>>> Even better if you offered the output from:
>>>
>>> small <- head(new_data4, 20)
>>> dump("small", 20),
>>>
>>> -- 
>>> David
>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> David Winsemius wrote:
>>>>>
>>>>>
>>>>> On Nov 14, 2009, at 1:21 PM, frenchcr wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> I want to go through a column in data called
>>>>>
>>>>> Bad name for a data.frame. Fortunes, "dog" and all that.
>>>>>
>>>>>> date_abandoned....data["date_abandoned"]....and remove all the  
>>>>>> rows
>>>>>> that
>>>>>> have numbers greater than 1,010,000.
>>>>>
>>>>> Are you doing archeology? Given what you say next I wondered what
>>>>> range you were really asking for.
>>>>>
>>>>>>
>>>>>> The dates are in the format 20091114 so i'm just going to treat  
>>>>>> them
>>>>>> as
>>>>>> numbers for clean up purposes.
>>>>>>
>>>>>>
>>>>>> I know that i use subset but not sure how to proceed from there.
>>>>>
>>>>> subdata <- subset(data, date_abandoned > "01010000"()
>>>>>
>>>>>
>>>>> The problem with > "1010000" is that your specified minimum point  
>>>>> had
>>>>> an insufficient number of "places" to be in YYYYMMDD format.
>>>>>
>>>>> --
>>>>>
>>>>> David Winsemius, MD
>>>>> Heritage Laboratories
>>>>> West Hartford, CT
>>>>>
>>>>> ______________________________________________
>>>>> R-help at r-project.org 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.
>>>>>
>>>>>
>>>>
>>>> -- 
>>>> View this message in context:
>>>> http://old.nabble.com/remove-row-if-the-column-%22date_abandoned%22-has-a-date-in-it-tp26352457p26354446.html
>>>> Sent from the R help mailing list archive at Nabble.com.
>>>>
>>>> ______________________________________________
>>>> R-help at r-project.org 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
>>> Heritage Laboratories
>>> West Hartford, CT
>>>
>>> ______________________________________________
>>> R-help at r-project.org 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.
>>>
>>>
>>
>> -- 
>> View this message in context:
>> http://old.nabble.com/remove-row-if-the-column-%22date_abandoned%22-has-a-date-in-it-tp26352457p26355689.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org 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
> Heritage Laboratories
> West Hartford, CT
> 
> ______________________________________________
> R-help at r-project.org 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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