R help - Sep 2011 - Problem with converting factors to numbers

Hi all,
I have a very simple problem, but i cant find a solution probably because i
search for the wrong keywords.

I have coordinates x and y. They look like this:
> str(data)
'data.frame':   13979 obs. of  2 variables:
 $ x               : Factor w/ 3815 levels
"","186011.4971280",..: 1528 1524
1524 1524 1524 ...
 $ y               : Factor w/ 3792 levels
"","449372.9599780",..: 1333 1116
1116 1116 1116 ...

> data$x[1:10]
 [1] 186843.8131840 186842.6156650 186842.6156650 186842.6156650
186842.6156650 186842.6156650 186842.6156650 186842.6156650
 [9] 186842.6156650 186842.6156650
3815 Levels:  186011.4971280 186021.0356270 186048.6246680 186051.3570180
186052.7204140 186052.9162970 ... 188132.9056840


I want them in *numbers*, so i run:
data$x2 <- as.numeric(data$x)

But what it did is this:
> data$x2[1:10]
 [1] 1528 1524 1524 1524 1524 1524 1524 1524 1524 1524

I tried converting it via character and then to numeric, but also that didnt
work.

Anyone ideas?






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this is an FAQ (forget which one), but the solution is:

as.numeric(as.character(data$x))

Sent from my iPad

On Sep 20, 2011, at 3:40, _Luc_ <l.temarvelde at nioo.knaw.nl> wrote:
> Hi all,
> I have a very simple problem, but i cant find a solution probably because i
> search for the wrong keywords.
> 
> I have coordinates x and y. They look like this:
> 
>> str(data)
> 'data.frame':   13979 obs. of  2 variables:
> $ x               : Factor w/ 3815 levels
"","186011.4971280",..: 1528 1524
> 1524 1524 1524 ...
> $ y               : Factor w/ 3792 levels
"","449372.9599780",..: 1333 1116
> 1116 1116 1116 ...
> 
> 
>> data$x[1:10]
> [1] 186843.8131840 186842.6156650 186842.6156650 186842.6156650
> 186842.6156650 186842.6156650 186842.6156650 186842.6156650
> [9] 186842.6156650 186842.6156650
> 3815 Levels:  186011.4971280 186021.0356270 186048.6246680 186051.3570180
> 186052.7204140 186052.9162970 ... 188132.9056840
> 
> 
> I want them in *numbers*, so i run:
> data$x2 <- as.numeric(data$x)
> 
> But what it did is this:
>> data$x2[1:10]
> [1] 1528 1524 1524 1524 1524 1524 1524 1524 1524 1524
> 
> I tried converting it via character and then to numeric, but also that
didnt
> work.
> 
> Anyone ideas?
> 
> 
> 
> 
> 
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/Problem-with-converting-factors-to-numbers-tp3826061p3826061.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Hi
> 
> [R] Problem with converting factors to numbers
> 
> Hi all,
> I have a very simple problem, but i cant find a solution probably 
because i
> search for the wrong keywords.
> 
> I have coordinates x and y. They look like this:
> 
> > str(data)
> 'data.frame':   13979 obs. of  2 variables:
>  $ x               : Factor w/ 3815 levels
"","186011.4971280",..: 1528
1524
> 1524 1524 1524 ...
>  $ y               : Factor w/ 3792 levels
"","449372.9599780",..: 1333
1116
> 1116 1116 1116 ...
> 
> 
> > data$x[1:10]
>  [1] 186843.8131840 186842.6156650 186842.6156650 186842.6156650
> 186842.6156650 186842.6156650 186842.6156650 186842.6156650
>  [9] 186842.6156650 186842.6156650
> 3815 Levels:  186011.4971280 186021.0356270 186048.6246680 
186051.3570180
> 186052.7204140 186052.9162970 ... 188132.9056840
> 
> 
> I want them in *numbers*, so i run:
> data$x2 <- as.numeric(data$x)
> 
> But what it did is this:
> > data$x2[1:10]
>  [1] 1528 1524 1524 1524 1524 1524 1524 1524 1524 1524
> 
> I tried converting it via character and then to numeric, but also that 
didnt
> work.
It shall work. However nobody knows how did you apply converting via 
character and numeric until you post the code you actually used.
>From str it seems to me that either your data are from beginning non 
numeric or you have some non numeric characters in your input data.

Regards
Petr
> 
> Anyone ideas?
> 
> 
> 
> 
> 
> 
> --
> View this message in context: 
http://r.789695.n4.nabble.com/Problem-with-
> converting-factors-to-numbers-tp3826061p3826061.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

ok great, as.numeric(as.character(data$x)) works perfectly.

I am sorry that i did not find this before making this post. 


@ peter
what did not work was:
data$x2 <- as.character(data$x) 
data$x3 <- as.numeric(data$x2) 

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