Dear Ruser's

I ask for helps on how to substitute missing values (NAs) by mean of the
group it is belonging to.

my dummy dataframe is:

> df
       group traits
1  BSPy01-10     NA
2  BSPy01-10    7.3
3  BSPy01-10    7.3
4  BSPy01-11    5.3
5  BSPy01-11    5.4
6  BSPy01-11    5.6
7  BSPy01-11     NA
8  BSPy01-11     NA
9  BSPy01-11    4.8
10 BSPy01-12    8.1
11 BSPy01-12    6.0
12 BSPy01-12    6.0
13 BSPy01-13    6.1


I want to substitute each "NA" by the group mean of which the "NA" is
belonging to. For example, substitute the first record of traits "NA" by the
mean of "BSPy01-10".

I have ever tried to solve this problem by using doBy package. But, I
failed. I ask for the right solutions by using doBy package or not.

The commands used and the output I got are as followed:

library(doBy)
df<-orderBy(~group,data=df)   # succeeded
f1<-function(x){m<-mean(x, na.ram=TRUE); x[is.na(x)]<-m; x} # succeeded
datatraits<-lapplyBy(traits~group,data=df, FUN=f1(traits)) # failed
errors: mean(x, na.ram = TRUE), can not find 'traits'.

Thanks in advance.

Sincerely,

Mao J-F

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