计算不包括R中某些列的行的平均值

Question

I am totally new to R and Stack Overflow so sorry if I ask this question in a weird way.

I have a dataset which was obtained through surveys. In this survey there is a subset of variables that are grouped together and I would like to get the mean of a subset of these variables.

So for example: I want the averages of columns 18-22 of respondent/row 138 with na.rm=TRUE

Is that possible?

Answer 1

Can easily be done with dplyr . In the example df is the dataset name and columavg will be the column to store the new value in.

library(dplyr)

df = df %>%
     mutate(columavg = case_when(row_number() == 138 ~ rowMeans(.[18:22], na.rm=TRUE),
                                 TRUE ~ 0))

or if you want just that single value

rowMeans(df[138,18:22], na.rm=TRUE)[[1]]