dplyr's arrange function - 3 solutions received - 1 New Question
Hello, I got 3 solutions to my earlier code. Thanks to the contributors. May I bring your attention to a new question below (with respect to David's solution)? 1) Thanks to Daniel Nordlund for the tips - replacing leading space with a 0 in the data. 2) Thanks to David Winsemius for his solution with the gtools::mixedorder function. I have added an argument to his. mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE), ] 3) Thanks to Jim Lemon's for his solution. I have prepended a minus sign to reverse the order. numprev<-as.numeric(sapply(strsplit(trimws(mydata$prevalence_c)," "),"[",1)) mydata[order(-numprev), ] (New)Question for solution 2: I want to keep only 2 variables (say, indicator and prevalence_c) in the output. Where to insert the additional code? Why does the following code fail?
mydata[ mixedorder(mydata$prevalence_c, decreasing=TRUE), c(mydata$indicator, mydata$prevalence_c) ]
Error in `[.data.frame`(mydata, mixedorder(mydata$prevalence_c, decreasing = TRUE), : undefined columns selected ********************
str(mydata)
Classes 'tbl_df', 'tbl' and 'data.frame': 10 obs. of 10 variables: $ indicator : chr "1. Health check-up" "2. Blood cholesterol checked " "3. Recieved flu vaccine" "4. Blood pressure checked" ... $ subgroup : chr "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ "Both sexes, ages =35 yrs""| __truncated__ ... $ n : num 2117 2127 2124 2135 1027 ... $ prevalence_c: chr "74.7 (1.20)" "90.3 (0.89)" "51.7 (1.35)" "93.2 (0.70)" ... $ prevalence_p: chr "77.2 (1.19)" "84.5 (1.14)" "50.0 (1.33)" "88.7 (0.88)" ... $ sensitivity : chr "87.4 (1.10)" "99.2 (0.27)" "97.0 (0.62)" "99.0 (0.27)" ... $ specificity : chr "68.3 (2.80)" "58.2 (3.72)" "93.5 (0.90)" "52.7 (3.90)" ... $ ppv : chr "90.4 (0.94)" "92.8 (0.85)" "93.7 (0.87)" "94.3 (0.63)" ... $ npv : chr "61.5 (3.00)" "92.8 (2.27)" "96.9 (0.63)" "87.5 (3.27)" ... $ kappa : chr "0.536 (0.029)" "0.676 (0.032)" "0.905 (0.011)" "0.626 (0.035)" ... Pradip K. Muhuri, AHRQ/CFACT 5600 Fishers Lane # 7N142A, Rockville, MD 20857 Tel: 301-427-1564 -----Original Message----- From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Daniel Nordlund Sent: Wednesday, June 15, 2016 6:37 PM To: r-help at r-project.org Subject: Re: [R] dplyr's arrange function
On 6/15/2016 2:08 PM, Muhuri, Pradip (AHRQ/CFACT) 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
The problem is that you are sorting a character variable.
testdata$prevalence
[1] "77.2 (1.19)" "84.5 (1.14)" "50.0 (1.33)" "88.7 (0.88)" "11.7 (1.02)" [6] "60.2 (1.41)" "6.1 (0.61)" "14.6 (1.00)" "72.6 (1.82)" "73.3 (2.37)"
Notice that the 7th element is "6.1 (0.61)". The first CHARACTER is a "6", so it is going to sort BEFORE the "50.0 (1.33)" (in descending order). If you want the character value of line 7 to sort last, it would need to be "06.1 (0.61)" or " 6.1 (0.61)" (notice the leading space). Hope this is helpful, Dan Daniel Nordlund Port Townsend, WA USA ______________________________________________ R-help at 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.