[R] odd feature

[Frank E Harrell Jr]

ivo welch wrote:
> Dear R wizards:
> 
> I just got stung by the ifelse() feature.
> 
> 
>>a <- 10:15
>>b <- 20:300
>>test <- 1
>>ifelse(test,a,b)
> 
> [1] 10
> 
> I had not realized that this was the default behavior---I had expected
> 10:15.  mea culpa.  however, I wonder whether it would make sense to
> replace ifelse with a different semantic, where if test is a single
> scalar, it means what a stupid user like me would imagine.
> 
> Aside, I like the flexibility of R, but I am not thrilled by all the
> recycling rules.  I either mean I want a scalar or a vector of
> equal/appropriate dimension.  I never want a recycle of a smaller
> vector.  (I do often use a recycle of a scalar.)
> 
> regards,
> 
> /iaw

The current behavior is logical to me.  Are you looking for if(test) a 
else b?
Frank
-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University