On Dec 3, 2014, at 7:43 PM, Muhuri, Pradip (SAMHSA/CBHSQ) wrote:
> Hello Chel and David,
>
> Thank you very much for providing new insights into this issue. Here is one
> more question. Why does the mutate () give incorrect results here?
>
> # The following gives INCORRECT results - mutated()ed object
> na.date.cases = ifelse(!is.na(oiddate),1,0)
>
> # The following gives CORRECT results
> new2$na.date.cases = ifelse(!is.na(new2$oiddate),1,0)
>
> ############################### reproducible example - slightly
> revised/modified ###############
> library(dplyr)
> # data object - description
>
> temp <- "id mrjdate cocdate inhdate haldate
> 1 2004-11-04 2008-07-18 2005-07-07 2007-11-07
> 2 NA NA NA NA
> 3 2009-10-24 NA 2011-10-13 NA
> 4 2007-10-10 NA NA NA
> 5 2006-09-01 2005-08-10 NA NA
> 6 2007-09-04 2011-10-05 NA NA
> 7 2005-10-25 NA NA 2011-11-04"
>
> # read the data object
>
> example.data <- read.table(textConnection(temp),
> colClasses=c("character", "Date", "Date", "Date", "Date"),
>
> header=TRUE, as.is=TRUE
> )
>
>
> # create a new column -dplyr solution (Acknowledgement: Arun)
>
> new1 <- example.data %>%
> rowwise() %>%
> mutate(oiddate=as.Date(max(mrjdate,cocdate, inhdate, haldate,
> na.rm=TRUE), origin='1970-01-01'),
> na.date.cases = ifelse(!is.na(oiddate),1,0)
> )
>
It would have been polite to include the warning printed to the console after
this line of code. It seems to me that this highlights the fact that you used
different logic in the two methods and got, therefore, different answers.
--
David.
> # create a new column - Base R solution (Acknowlegement: Mark Sharp)
>
> new2 <- example.data
> new2$oiddate <- as.Date(sapply(seq_along(new2$id), function(row) {
> if (all(is.na(unlist(example.data[row, c('mrjdate','cocdate', 'inhdate',
> 'haldate')])))) {
> max_d <- NA
> } else {
> max_d <- max(unlist(example.data[row, c('mrjdate','cocdate', 'inhdate',
> 'haldate')]), na.rm = TRUE)
> }
> max_d}),
> origin = "1970-01-01")
>
> new2$na.date.cases = ifelse(!is.na(new2$oiddate),1,0)
>
>
> identical(new1, new2)
>
> table(new1$oiddate)
> table(new2$oiddate)
>
> # print records
>
> print (new1); print(new2)
>
> Pradip K. Muhuri, PhD
> SAMHSA/CBHSQ
> 1 Choke Cherry Road, Room 2-1071
> Rockville, MD 20857
> Tel: 240-276-1070
> Fax: 240-276-1260
>
> -----Original Message-----
> From: Chel Hee Lee [mailto:chl...@mail.usask.ca]
> Sent: Wednesday, December 03, 2014 8:48 PM
> To: Muhuri, Pradip (SAMHSA/CBHSQ); r-help@r-project.org
> Subject: Re: [R] Getting the most recent dates in a new column from dates in
> four columns using the dplyr package (mutate verb)
>
> The output in the object 'new1' are apparently same the output in the object
> 'new2'. Are you trying to compare the entries of two outputs 'new1' and
> 'new2'? If so, the function 'all()' would be useful:
>
>> all(new1 == new2, na.rm=TRUE)
> [1] TRUE
>
> If you are interested in the comparison of two objects in terms of class,
> then the function 'identical()' is useful:
>
>> attributes(new1)
> $names
> [1] "id" "mrjdate" "cocdate" "inhdate" "haldate" "oldflag"
>
> $class
> [1] "rowwise_df" "tbl_df" "tbl" "data.frame"
>
> $row.names
> [1] 1 2 3 4 5 6 7
>
>> attributes(new2)
> $names
> [1] "id" "mrjdate" "cocdate" "inhdate" "haldate" "oiddate"
>
> $row.names
> [1] 1 2 3 4 5 6 7
>
> $class
> [1] "data.frame"
>
> I hope this helps.
>
> Chel Hee Lee
>
> On 12/03/2014 04:10 PM, Muhuri, Pradip (SAMHSA/CBHSQ) wrote:
>> Hello,
>>
>> Two alternative approaches - mutate() vs. sapply() - were used to get the
>> desired results (i.e., creating a new column of the most recent date from 4
>> dates ) with help from Arun and Mark on this forum. I now find that the two
>> data objects (created using two different approaches) are not identical
>> although results are exactly the same.
>>
>> identical(new1, new2)
>> [1] FALSE
>>
>> Please see the reproducible example below.
>>
>> I don't understand why the code returns FALSE here. Any hints/comments
>> will be appreciated.
>>
>> Thanks,
>>
>> Pradip
>>
>> ############################################# reproducible example
>> ########################################
>> library(dplyr)
>> # data object - description
>>
>> temp <- "id mrjdate cocdate inhdate haldate
>> 1 2004-11-04 2008-07-18 2005-07-07 2007-11-07
>> 2 NA NA NA NA
>> 3 2009-10-24 NA 2011-10-13 NA
>> 4 2007-10-10 NA NA NA
>> 5 2006-09-01 2005-08-10 NA NA
>> 6 2007-09-04 2011-10-05 NA NA
>> 7 2005-10-25 NA NA 2011-11-04"
>>
>> # read the data object
>>
>> example.data <- read.table(textConnection(temp),
>> colClasses=c("character", "Date", "Date", "Date",
>> "Date"),
>> header=TRUE, as.is=TRUE
>> )
>>
>>
>> # create a new column -dplyr solution (Acknowledgement: Arun)
>>
>> new1 <- example.data %>%
>> rowwise() %>%
>> mutate(oldflag=as.Date(max(mrjdate,cocdate, inhdate, haldate,
>>
>> na.rm=TRUE), origin='1970-01-01'))
>>
>> # create a new column - Base R solution (Acknowlegement: Mark Sharp)
>>
>> new2 <- example.data
>> new2$oiddate <- as.Date(sapply(seq_along(new2$id), function(row) {
>> if (all(is.na(unlist(example.data[row, c('mrjdate','cocdate', 'inhdate',
>> 'haldate')])))) {
>> max_d <- NA
>> } else {
>> max_d <- max(unlist(example.data[row, c('mrjdate','cocdate', 'inhdate',
>> 'haldate')]), na.rm = TRUE)
>> }
>> max_d}),
>> origin = "1970-01-01")
>>
>> identical(new1, new2)
>>
>> # print records
>>
>> print (new1); print(new2)
>>
>> Pradip K. Muhuri
>> SAMHSA/CBHSQ
>> 1 Choke Cherry Road, Room 2-1071
>> Rockville, MD 20857
>> Tel: 240-276-1070
>> Fax: 240-276-1260
>>
>> -----Original Message-----
>> From: r-help-boun...@r-project.org
>> [mailto:r-help-boun...@r-project.org] On Behalf Of Muhuri, Pradip
>> (SAMHSA/CBHSQ)
>> Sent: Sunday, November 09, 2014 6:11 AM
>> To: 'Mark Sharp'
>> Cc: r-help@r-project.org
>> Subject: Re: [R] Getting the most recent dates in a new column from
>> dates in four columns using the dplyr package (mutate verb)
>>
>> Hi Mark,
>>
>> Your code has also given me the results I expected. Thank you so much for
>> your help.
>>
>> Regards,
>>
>> Pradip
>>
>> Pradip K. Muhuri, PhD
>> SAMHSA/CBHSQ
>> 1 Choke Cherry Road, Room 2-1071
>> Rockville, MD 20857
>> Tel: 240-276-1070
>> Fax: 240-276-1260
>>
>>
>> -----Original Message-----
>> From: Mark Sharp [mailto:msh...@txbiomed.org]
>> Sent: Sunday, November 09, 2014 3:01 AM
>> To: Muhuri, Pradip (SAMHSA/CBHSQ)
>> Cc: r-help@r-project.org
>> Subject: Re: [R] Getting the most recent dates in a new column from
>> dates in four columns using the dplyr package (mutate verb)
>>
>> Pradip,
>>
>> mutate() works on the entire column as a vector so that you find the maximum
>> of the entire data set.
>>
>> I am almost certain there is some nice way to handle this, but the sapply()
>> function is a standard approach.
>>
>> max() does not want a dataframe thus the use of unlist().
>>
>> Using your definition of data1:
>>
>> data3 <- data1
>> data3$oidflag <- as.Date(sapply(seq_along(data3$id), function(row) {
>> if (all(is.na(unlist(data1[row, -1])))) {
>> max_d <- NA
>> } else {
>> max_d <- max(unlist(data1[row, -1]), na.rm = TRUE)
>> }
>> max_d}),
>> origin = "1970-01-01")
>>
>> data3
>> id mrjdate cocdate inhdate haldate oidflag
>> 1 1 2004-11-04 2008-07-18 2005-07-07 2007-11-07 2008-07-18
>> 2 2 <NA> <NA> <NA> <NA> <NA>
>> 3 3 2009-10-24 <NA> 2011-10-13 <NA> 2011-10-13
>> 4 4 2007-10-10 <NA> <NA> <NA> 2007-10-10
>> 5 5 2006-09-01 2005-08-10 <NA> <NA> 2006-09-01
>> 6 6 2007-09-04 2011-10-05 <NA> <NA> 2011-10-05
>> 7 7 2005-10-25 <NA> <NA> 2011-11-04 2011-11-04
>>
>>
>>
>> R. Mark Sharp, Ph.D.
>> Director of Primate Records Database
>> Southwest National Primate Research Center Texas Biomedical Research
>> Institute P.O. Box 760549 San Antonio, TX 78245-0549
>> Telephone: (210)258-9476
>> e-mail: msh...@txbiomed.org
>>
>>
>>
>>
>>
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>> PLEASE do read the posting guide
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>>
>> ______________________________________________
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>> PLEASE do read the posting guide
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>>
David Winsemius
Alameda, CA, USA
______________________________________________
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