R help - Feb 2009 - parsing problem

Hi all,
I am trying to parse a vector for caliculating minimum in that vector the
vector having values like

1        Kontrolle
2          Placebo
3         125mg/kg
4         250mg/kg
5         500mg/kg
6        1000mg/kg
hear i tries for comverting it into numeric with using  "as.numaric()"
 function
but i got values like
5
6
2
3
4
1

it gives 1000mg/kg is the least one
but i have toget 125mg/kg as the minimum value
for that i have to remove all the strings and spetial charecters from that
for that i used      "parse()"      but i am not able to get the out
put

can anyone suggest how I will solve it


thanks in advance



regards;
kiran

	[[alternative HTML version deleted]]

-----Original Message-----
From: Nutter, Benjamin 
Sent: Monday, February 02, 2009 7:37 AM
To: 'venkata kirankumar'
Subject: RE: [R] parsing problem

This is how I would approach it.  I'd be happy to know if there's a
better way.

#*** Initial Data Frame
x <-
c("Kontrolle","Placebo","125mg/kg","250mg/kg","500mg/kg","1000mg/kg"))
x

#*** Convert alphabetical and punctuation characters to "" (see
?regex)
y <- gsub("[[:alpha:],[:punct:]]","",x)
y

#*** Convert character strings to numeric
z <- as.numeric(y)
z

#*** Calculate minimum
min(df$z,na.rm=TRUE)




-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of venkata kirankumar
Sent: Monday, February 02, 2009 7:18 AM
To: r-help at r-project.org
Subject: [R] parsing problem

Hi all,
I am trying to parse a vector for caliculating minimum in that vector
the
vector having values like

1        Kontrolle
2          Placebo
3         125mg/kg
4         250mg/kg
5         500mg/kg
6        1000mg/kg
hear i tries for comverting it into numeric with using  "as.numaric()"
 function
but i got values like
5
6
2
3
4
1

it gives 1000mg/kg is the least one
but i have toget 125mg/kg as the minimum value
for that i have to remove all the strings and spetial charecters from
that
for that i used      "parse()"      but i am not able to get the out
put

can anyone suggest how I will solve it


thanks in advance



regards;
kiran

	[[alternative HTML version deleted]]

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venkata kirankumar <kiran4u2all <at> gmail.com>
writes:
> I am trying to parse a vector for caliculating minimum in that vector the
> vector having values like
> 
> 1        Kontrolle
> 2          Placebo
> 3         125mg/kg
> 4         250mg/kg
> 5         500mg/kg
> 6        1000mg/kg
> hear i tries for comverting it into numeric with using 
"as.numaric()"
>  function
> but i got values like
> 5
> 6
> 2
> 3
> 4
> 1
> 
> can anyone suggest how I will solve it
> 
> thanks in advance
> 
> regards;
> kiran
> 
Your Kontrolle is being treated as a factor so you
are seeing only the codes of the levels.  There is
probably something more elegant, but you need
something like,

as.numeric(sapply(with(dd, strsplit(levels(Placebo)[Placebo], "m")),
"[[", 1))

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