[R] dplyr's arrange function

[Jim Lemon]

Hi Pradip,
I'll assume that you are reading the data from a file:

pm.df<-read.csv("pmdat.txt",stringsAsFactors=FALSE)
# create a vector of numeric values of prevalence
numprev<-as.numeric(sapply(strsplit(trimws(pm.df$prevalence)," "),"[",1))
# order the data frame by that vector
pm.df[order(numprev),]

Jim


On Thu, Jun 16, 2016 at 7:08 AM, Muhuri, Pradip (AHRQ/CFACT)
<Pradip.Muhuri at ahrq.hhs.gov> wrote:
> Hello,
>
> I am using the dplyr's arrange() function to sort  one of the  many data frames  on a character variable (named "prevalence").
>
> Issue: I am not getting the desired output  (line 7 is the problem, which should be the very last line in the sorted data frame) because the sorted field is character, not numeric.
>
> The reproducible example and the output are appended below.
>
> Is there any work-around  to convert/treat  this character variable (named "prevalence" in the data frame below)  as numeric before using the arrange() function within the dplyr package?
>
> Any hints will be appreciated.
>
> Thanks,
>
> Pradip Muhuri
>
> # Reproducible Example
>
> library("readr")
> testdata <- read_csv(
> "indicator,  prevalence
> 1. Health check-up, 77.2 (1.19)
> 2. Blood cholesterol checked,  84.5 (1.14)
> 3. Recieved flu vaccine, 50.0 (1.33)
> 4. Blood pressure checked, 88.7 (0.88)
> 5. Aspirin use-problems, 11.7 (1.02)
> 6.Colonoscopy, 60.2 (1.41)
> 7. Sigmoidoscopy,  6.1 (0.61)
> 8. Blood stool test, 14.6 (1.00)
> 9.Mammogram,  72.6 (1.82)
> 10. Pap Smear test, 73.3 (2.37)")
>
> # Sort on the character variable in descending order
> arrange(testdata, desc(prevalence))
>
> # Results from Console
>
>                       indicator  prevalence
>                           (chr)       (chr)
> 1     4. Blood pressure checked 88.7 (0.88)
> 2  2. Blood cholesterol checked 84.5 (1.14)
> 3            1. Health check-up 77.2 (1.19)
> 4            10. Pap Smear test 73.3 (2.37)
> 5                   9.Mammogram 72.6 (1.82)
> 6                 6.Colonoscopy 60.2 (1.41)
> 7              7. Sigmoidoscopy  6.1 (0.61)
> 8       3. Recieved flu vaccine 50.0 (1.33)
> 9           8. Blood stool test 14.6 (1.00)
> 10      5. Aspirin use-problems 11.7 (1.02)
>
>
> Pradip K. Muhuri,  AHRQ/CFACT
>  5600 Fishers Lane # 7N142A, Rockville, MD 20857
> Tel: 301-427-1564
>
>
>
>
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