Recoding Column Numerical Variables

Question

I have a larger dataset where I need to change a column numercal variable to categorical variable. A sample of the data is below:

dat1 <- read.table(header=TRUE, text="
                   ID  Pa  Gu  Ta
                   8645    1  Gel294  Tel452
                   6228    2  Gel294  Tel467
                   5830    3  Gel294  Tel467
                   1844    3  Gel295  Tel467
                   4461    4  Gel295  Tel467
                   2119    5  Gel294  Tel452
                   2119    5  Gel294  Tel452
                   ")
dat1
    ID Pa     Gu     Ta
1 8645  1 Gel294 Tel452
2 6228  2 Gel294 Tel467
3 5830  3 Gel294 Tel467
4 1844  3 Gel295 Tel467
5 4461  4 Gel295 Tel467
6 2119  5 Gel294 Tel452
7 2119  5 Gel294 Tel452

The variables in column Pa needs to be replaced by the following:

dat2 <- read.table(header=TRUE, text="
                   Pa  Abbr  
                   1    MNDF
                   2    CVDE
                   3    EEED
                   4    WERD
                   5    PPOL
                   ")
dat2
  Pa Abbr
1  1 MNDF
2  2 CVDE
3  3 EEED
4  4 WERD
5  5 PPOL

For a smaller dataset, I can do it manually by recode function in car package.

library(car)
dat1$Pa <- recode(dat1$Pa, "1='MNDF'; 2='CVDE'; 3='EEED'; 4='WERD'; 5='PPOL'")
dat1
    ID   Pa     Gu     Ta
1 8645 MNDF Gel294 Tel452
2 6228 CVDE Gel294 Tel467
3 5830 EEED Gel294 Tel467
4 1844 EEED Gel295 Tel467
5 4461 WERD Gel295 Tel467
6 2119 PPOL Gel294 Tel452
7 2119 PPOL Gel294 Tel452

I need a proper function or code that can replace the manual inputting in recode.

akrun · Accepted Answer · 2016-06-28 15:46:43Z

1

We can use match from base R

dat1$Pa <- dat2$Abbr[match(dat1$Pa, dat2$Pa)]
dat1
#    ID   Pa     Gu     Ta
#1 8645 MNDF Gel294 Tel452
#2 6228 CVDE Gel294 Tel467
#3 5830 EEED Gel294 Tel467
#4 1844 EEED Gel295 Tel467
#5 4461 WERD Gel295 Tel467
#6 2119 PPOL Gel294 Tel452
#7 2119 PPOL Gel294 Tel452

answered Jun 28, 2016 at 15:46

akrun

891k38 gold badges590 silver badges700 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Recoding Column Numerical Variables

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related