How do I recode multiple variables from string to numeric?-CodePudding

I am trying to recode multiple columns of data from string variables (e.g. "None of the time", "Some of the time", "Often"...) to numeric values (e.g. "None of the time" = 0). I have seen a number of different responses to similar questions but when I have tried these they seem to remove all of the data and replace it with NA.

For_Analysis <- data.frame(Q11_1=c("None of the time", "Often", "Sometimes"),
 Q11_2=c("Sometimes", "Often", "Never"), Q11_3=c("Never", "Never", "Often"))

For_Analysis <- For_Analysis%>% 
  mutate_at(c("Q11_1", "Q11_2", "Q11_3"), 
            funs(recode(., "None of the time"=1,  "Rarely"=2,
                        "Some of the time"=3, "Often"=4, "All of the time"=5)))

When I run this second bit of code I get the following output

## There were 14 warnings (use warnings() to see them)

And all of the data within the dataframe is recoded to NA instead of the numeric values I want.

CodePudding user response：

You are getting an error because there are some values which do not match. Also you can replace mutate_at with across.

library(dplyr)

For_Analysis <- For_Analysis%>% 
  mutate(across(starts_with('Q11'), ~recode(., "None of the time"=1,  "Rarely"=2,
                        "Sometimes"=3, "Often"=4, "All of the time"=5, "Never" = 1)))

For_Analysis

#  Q11_1 Q11_2 Q11_3
#1     1     3     1
#2     4     4     1
#3     3     1     4

I have taken the liberty to assume "Never" is same as "None of the time" and coded as 1.

CodePudding user response：

The following method seems to have worked for my issue (recoding string variables to numeric in multiple columns):

For_Analysis <- data.frame(Q11_1=c("Never", "Often", "Sometimes"),
 Q11_2=c("Sometimes", "Often", "Never"), Q11_3=c("Never", "Never", "Often"))

New_Values <- c(1, 2, 3, 4, 5)
Old_Values <- unique(For_Analysis$Q11_1)

For_Analysis[1:3] <- as.data.frame(sapply(For_Analysis[1:3],
                     mapvalues, from = Old_Values, to = New_Values))

Thanks for the help!

CodePudding user response：

The easiest way to convert it to a variable of type factor and then to numeric.

library(tidyverse)

For_Analysis <- data.frame(Q11_1=c("None of the time", "Often", "Sometimes"),
                           Q11_2=c("Sometimes", "Often", "Never"), Q11_3=c("Never", "Never", "Often"))

fRecode = function(x) x %>% fct_inorder() %>% as.numeric()
For_Analysis %>% mutate_all(fRecode)

output

  Q11_1 Q11_2 Q11_3
1     1     1     1
2     2     2     1
3     3     3     2