[R] working on a vector with named elements - unname

[Petr PIKAL]

Hi

 
> Hi, I am working under R2.11.1 Windows.

Rather old one, consider upgrading

> I work with a set of parameters which is save under a vector. I think it 
is
> easier to understand, which parameter is called in the vector by naming 
all
> vector elements. For example, we have a vector which the parameters 
a,b,c,d.
> Is it normal to allow, that there are two elements with the same name? I
> think for lists, it is also possible. If I want to regroup the elements 
and
> work on them, they always keep their old name. Event if I attribute to a 
new
> name, the new name and the old name merge (lign3)
> 
> v<-c("a"=3,"a"=4,"c"=5,"d"=6)
> v["a"] #output 3
> c("n"=v["a"]+v["c"],"n1"=v["d"]*3) # "n.a"=8 "n1.d"=18
> 
> Is there any better solution/datatype to this ?

I am not at all an expert in such things but named vector seems to me 
rather strange solution.

compare

v<-c("a"=3,"a"=4,"c"=5,"d"=6)

vl<-list("a"=c(3,4),"c"=5,"d"=6)

> v["a"]
a 
3 
> vl["a"]
$a
[1] 3 4

> vl[["a"]]
[1] 3 4
>

This seems to me not correct
> c("n"=v["a"]+v["c"])
n.a 
  8 

as there are two values named "a", why only first shall be used?

while this seems to me correct
> c("n"=vl[["a"]]+vl[["c"]])
n1 n2 
 8  9 

both "a" values are included in computation

> 
> c("n"=unname(v["a"])+unname(v["c"]),"n1"=unname(v["d"])*3) # "n"=8 
"n1"=18

Instead of
c("n"=unname(v["a"])+unname(v["c"]),"n1"=unname(v["d"])*3)
 n n1 
 8 18 

or
c("n"=vl[["a"]]+vl[["c"]],"n1"=vl[["d"]]*3)
n1 n2 n1 
 8  9 18 

I would use list which again seems to get more reasonable result.

list("n"=vl[["a"]]+vl[["c"]],"n1"=vl[["d"]]*3)
$n
[1] 8 9

$n1
[1] 18

Lists are not as complicated as they seems to be when you start with them. 
You can imagine them as a chest of drawers and you can store any kind of 
information in it. You can easily access only one ore some set of drawers.

Regards
Petr

> 
> Thanks a lot
> 
> 
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