[R] Time intervals is converted into seconds after converting list of dfs into a single Df.

[David Winsemius]

Perhaps some modification of

masterList <- list()

for( dfnum in seq_along(ListOfDFs)){

          masterList <- rbind(masterList, ListOfDFs[[dfnum]])

                                                                }

  masterList

#---------------

    id         dates1          dates2             interaction
1  1 2010-02-04 2010-09-04 2010-09-04 UTC--2011-01-01 UTC
2  1 2011-02-04 2011-01-01 2010-09-04 UTC--2011-01-01 UTC
3  2 2010-02-04 2010-09-04 2010-09-04 UTC--2011-01-01 UTC

4  2 2011-02-04 2011-01-01 2010-09-04 UTC--2011-01-01


You could add features to the for-loop such as printing a message to the 
console every 100 dfs or perhaps garbage collection although that should 
be handled automagically. Messages would probably reassure you that the 
process was not "hanging". (My suspicion is that the process was 
continuing but you were just too impatient.)

Note; you are posting in HTML and including non-printing characters in 
you code.


-- 

David


On 12/24/19 10:53 AM, Allaisone 1 wrote:
> Hi dear Patrick ,
>
> Thanks for your replay. Below is a reproducible example . First,  I generated two  similar Dfs with one column contains the interval. Then, I put the 2 dfs in a list. Now, converting this list into df provides different results depending on the code. See below for more details.
>
>
>   # dataframe 1​
>
> id <- c(1,1)​
>
> dates1 <- c("2010/2/4","2011/2/4")​
>
> dates2 <- c("2010/9/4","2011/1/1")​
>
> df1 <- data.frame(id,dates1,dates2)​
>
> df1[,2] <- as.Date(df1[,2])​
>
> df1[,3] <- as.Date(df1[,3])​
>
> df1$interaction <- intersect(interval(df1[1,2],df1[2,2]),interval(df1[1,3],df1[2,3]))​
>
>    ​
>
>    # Dataframe 2​
>
> id <- c(2,2)​
>
> dates1 <- c("2010/1/4","2011/2/4")​
>
> dates2 <- c("2010/10/4","2011/1/16")​
>
> df2 <- data.frame(id,dates1,dates2)​
>
> df2[,2] <- as.Date(df1[,2])​
>
> df2[,3] <- as.Date(df1[,3])​
>
>
> df2$interaction <- intersect(interval(df1[1,2],df1[2,2]),interval(df1[1,3],df1[2,3]))​
>
>
>
>   # 2 datframes in a list :​
>
>   ListOfDFs <- list(df1,df2)​
>
>   # Convert list of Dfs into a single df :-​
>
>   SingDF <- ldply( ListOfDFs,data.frame)​
>
>         # The interval has been converted into numbers which is not what I want.​
>
>         #​but trying this code :
>   SingDF <- do.call(rbind,ListOfDFs)​
>
>         # It works perfectly but only with this example as​ we have only 2 datframes. Howver, in my actual data I have​ around 8000 datframes. Applying this code to it , make R code​ freezes and I waited for many hours but it still freezes with​ no results generated.​
>
>   Could anyone please suggest any alternative syntax or modifications to the codes above?
>
> Kind Regards
>   ​
>
>
>
> Sent from Outlook
> ________________________________
> From: Patrick (Malone Quantitative) <malone using malonequantitative.com>
> Sent: 24 December 2019 17:01:59
> To: Allaisone 1 <Allaisone1 using hotmail.com>
> Cc: r-help using r-project.org <r-help using r-project.org>
> Subject: Re: [R] Time intervals is converted into seconds after converting list of dfs into a single Df.
>
> You didn't provide a reproducible example for testing (or post in
> plain text), but lubridate has an as.interval() function. You'll need
> to be able to extract the start time, though, for use in the function.
>
> On Tue, Dec 24, 2019 at 11:54 AM Allaisone 1 <Allaisone1 using hotmail.com> wrote:
>>
>> Hi dear group ,
>>
>> I have list of datframes with similar column names. I want to rebind all dataframes so I have a single dataframe. One of the column's in each df is of 'interval' time class which was generated from 'lubridate' package.
>>
>> The problem is that when I convert the list of dfs into a single df using any of the below codes :
>>
>> Library(plyr)
>> MySingleDf <- ldply(MyListOfDfs, data.frame)
>> Or
>> MySingleDf <- ldply(MyListOfDfs, rbind)
>> Or
>> MySingleDf <- rebind. fill (MyListOfDfs)
>>
>> What heppens is that  time intervals which looks like : 2010-4-5 UTC--2011-7-9 UTC is converted into a single numeric value which seems to be the difference between the 2 dates in seconds.
>>
>> When I use :
>> MySingleDf <- do.call ("rbind",MyListOfDfs)
>>
>> The code is freezes and it shows like of the data are being analysed but no result. I have used this code previously for the same purpose but with another datse and it works perfectly.
>>
>> What I want to see is that time intervals are shown as they are but not converted into seconds.
>>
>> Could you please suggest any alternative syntax or modifications to my codes ?
>>
>> Thank you so much in advance
>>
>> Regards
>>
>>
>>
>>          [[alternative HTML version deleted]]
>>
>> ______________________________________________
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> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help using 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.