[R] dplyr's arrange function

[Muhuri, Pradip (AHRQ/CFACT)]

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