with(data.frame,ifelse(___,___,___))

-----Original Message-----
From: r-help-bounces at r-project.org 
[mailto:r-help-bounces at r-project.org] On Behalf Of Jim Moon
Sent: Wednesday, December 22, 2010 5:05 PM
To: R-help at r-project.org
Subject: [R] with(data.frame,ifelse(___,___,___))

Hello, All,

Mac OS 10.6.5
R64 2.11.1

This works as expected:

f1 = c(0.084, 0.099, 0)
data= data.frame(f1)
data$f1=with(data,ifelse(f1==0, 0.0001, f1))
data

     f1
1 0.0840
2 0.0990
3 0.0001

Substituting 'f1==0' with 'T' produces the expected result:

f1 = c(0.084, 0.099, 0)
data= data.frame(f1)
data$f1=with(data,ifelse(T, 0.0001, f1))

data

     f1
1 1e-04
2 1e-04
3 1e-04

But, substituting 'f1==0'  or 'T' with 'F' does not produce 
the expected result:

f1 = c(0.084, 0.099, 0)
data= data.frame(f1)
data$f1=with(data,ifelse(F, 0.0001, f1))
data

     f1
1 0.084
2 0.084
3 0.084

I would expect this:
     f1
1 0.084
2 0.099
3 0

Is with(data.frame,ifelse(___,___,___)) broken, or does my 
interpretation of it need fixing?

Thank you for your time.

Jim

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