R help - Sep 2013 - change specific factor level values to NA in data frame

Dear R-users

I am trying to replace specific factor level values in a data frame
with NAs. The data frame includes different kind of variables (e.g,
characters, numbers, and factors). I'd like to replace all 'Not
applicable', 'Invalid', 'and Missing' for NA.

For example:

f.level <- c('Yes', 'No', 'Not applicable',
'Invalid', 'Missing')
df <- data.frame(x1=runif(100), x2=sample(f.level, 100, replace=T),
x3=sample(f.level, 100, replace=T))

I try changing the values by
df[df %in% c('Not applicable', 'Invalid', 'Missing'), ]
<- NA

but nothing seems to change
summary(df)

My data frame has many more factors. Any advice?

Thank you,
Daniel

Hello,

A possibility is the following.



icol <- sapply(df, is.factor)
df[icol] <- lapply(df[icol], function(x){
	x[as.character(x)  %in% c('Not applicable', 'Invalid',
'Missing')] <- NA
	x})


Hope this helps,

Rui Barradas

Em 30-09-2013 10:42, Daniel Caro escreveu:
> Dear R-users
>
> I am trying to replace specific factor level values in a data frame
> with NAs. The data frame includes different kind of variables (e.g,
> characters, numbers, and factors). I'd like to replace all 'Not
> applicable', 'Invalid', 'and Missing' for NA.
>
> For example:
>
> f.level <- c('Yes', 'No', 'Not applicable',
'Invalid', 'Missing')
> df <- data.frame(x1=runif(100), x2=sample(f.level, 100, replace=T),
> x3=sample(f.level, 100, replace=T))
>
> I try changing the values by
> df[df %in% c('Not applicable', 'Invalid',
'Missing'), ] <- NA
>
> but nothing seems to change
> summary(df)
>
> My data frame has many more factors. Any advice?
>
> Thank you,
> Daniel
>
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