Creating a subset of a data frame with specific years

Question

I am using a data frame from WDI and am attempting to clean a merged dataset.

One of the two merged datasets only has values at 2000,2005,2010, and so I would like to have a subsetted data frame that only includes those years (for each country etc).

My code is as follows:

WB_Merge1 = subset(WB_Merge, select = c(year==2000 | year==2005 | year==2010))

However, when I run it in R it creates a data frame that now has all 5502 observations but no variables?

Could anyone help? Many thanks.

See the posts up top for how to do this generally. In your specific case, it seems like you misread the `subset` docs: "select: expression, indicating columns to select from a data frame." — camille, Mar 02 '22 at 23:35

jay.sf · Accepted Answer · 2022-03-01T15:18:26.540

You just used the wrong argument, to select rows you want subset=.

subset(dat, subset=c(year == 2000 | year == 2005 | year == 2010))

Or more concise:

subset(dat, subset=year %in% c(2000, 2005, 2010))
#    year          x          z
# 1  2000 -0.4703161 0.62147778
# 6  2005 -0.6667708 0.03479132
# 11 2010 -0.8059292 0.43732005

select= is for the columns.

subset(dat, subset=year %in% c(2000, 2005, 2010), select=c(year, z))
#    year          z
# 1  2000 0.62147778
# 6  2005 0.03479132
# 11 2010 0.43732005

Note, that if you provide the arguments in the right order, you may leave out the argument names and just do:

subset(dat, year %in% c(2000, 2005, 2010), c(year, z))

Data:

set.seed(42)
dat <- data.frame(year=2000:2022, x=rnorm(23), z=runif(23))

score 0 · Answer 2 · answered Mar 01 '22 at 14:50

0

try:

require(dplyr)
WB_Merge1 <- filter(WB_Merge, year %in% c(2000, 2005, 2010)

answered Mar 01 '22 at 14:50

Tur

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score 0 · Answer 3 · answered Mar 01 '22 at 15:19

Another solution with which()

Sample data:

set.seed(42)
data <- data.frame(year=2000:2022, x=rnorm(23), z=runif(23))

Sample code:

new.data <- data[ which( data$year == 2000 | data$year == 2005 | data$year == 2010) , ]

Output:

   year          x         z
1  2000  1.3709584 0.8877549
6  2005 -0.1061245 0.3467482
11 2010  1.3048697 0.6772768

Creating a subset of a data frame with specific years

3 Answers3