R help - Jun 2009 - how to use "lapplyBy" function of "doBy" package

Dear Ruser's

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" in the dummy dataframe.

I have ever tried to solve this problem by using doBy package. But, I
failed. I ask for the advice on how to use "lapplyBy" function of
"doBy"
package.

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'.

dummy dataframe:
> 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

Thanks in advance.

Sincerely,

Mao J-F

	[[alternative HTML version deleted]]

Here are four ways:


# using lapplyBy - DF is already sorted by group
library(doBy)
f <- function(x) {
	x$traits[is.na(x$traits)] <- mean(x$traits, na.rm = TRUE)
	x
}
do.call(rbind, lapplyBy(~ group, DF, f))

# using by - same f as before
do.call(rbind, by(DF, DF$group, f))

# using ave - nondestructive
g <- function(x) {
	x[is.na(x)] <- mean(x, na.rm = TRUE)
	x
}
transform(DF, traits = ave(DF$traits, DF$group, FUN = g))

# using ave - same but modifies DF - same g as before
DF$traits <- ave(DF$traits, DF$group, FUN = mean.na)


On Mon, Jun 8, 2009 at 10:01 PM, Mao Jianfeng<jianfeng.mao at gmail.com>
wrote:
> Dear Ruser's
>
> 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" in the dummy dataframe.
>
> I have ever tried to solve this problem by using doBy package. But, I
> failed. I ask for the advice on how to use "lapplyBy" function of
"doBy"
> package.
>
> 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'.
>
> dummy dataframe:
>> 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
>
> Thanks in advance.
>
> Sincerely,
>
> Mao J-F
>
> ? ? ? ?[[alternative HTML version deleted]]
>
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