R help - Jan 2014 - calculate an value in dependence of another column

Hello together,

i have a little problem, to create a new column, in a data.frame.
I know i can calculate one column with as a example 2 like this:
ORDER$WEIGHT <- ORDER$VALUE * 2

But how can i create the ORDER$WEIGHT with different numbers, like this one.

I have a data.frame like this one:

ORDER   DESTINY    VALUE
A         NY          100
B         BER          10
C         FRA         100
D         WAS         50

I want now the column ORDER$WEIGHT in dependence of "DESTINY". NY
should be
*3, BER *2, FRA*1 and WAS * 4.

The solution look like this one:

ORDER   DESTINY    VALUE   WEIGHT
A         NY          100          300
B         BER          10             20
C         FRA         100            100
D         WAS         50             200

Maybe anyone can help me, how i can do this?

Thank you.



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Hi, Mat,

e. g., try something like

ORDER$VALUE * c( NY = 3, BER = 2, FRA = 1, WAS = 4)[ ORDER$DESTINY]

  Hth  --  Gerrit

On Fri, 17 Jan 2014, Mat wrote:
> Hello together,
>
> i have a little problem, to create a new column, in a data.frame.
> I know i can calculate one column with as a example 2 like this:
> ORDER$WEIGHT <- ORDER$VALUE * 2
>
> But how can i create the ORDER$WEIGHT with different numbers, like this
one.
>
> I have a data.frame like this one:
>
> ORDER   DESTINY    VALUE
> A         NY          100
> B         BER          10
> C         FRA         100
> D         WAS         50
>
> I want now the column ORDER$WEIGHT in dependence of "DESTINY". NY
should be
> *3, BER *2, FRA*1 and WAS * 4.
>
> The solution look like this one:
>
> ORDER   DESTINY    VALUE   WEIGHT
> A         NY          100          300
> B         BER          10             20
> C         FRA         100            100
> D         WAS         50             200
>
> Maybe anyone can help me, how i can do this?
>
> Thank you.

Hi,

You could try:
dat1 <- read.table(text="ORDER? DESTINY??? VALUE
A??????? NY????????? 100
B??????? BER????????? 10
C??????? FRA??????? 100
D??????? WAS??????? 50
E??????? BER????????
20",sep="",header=TRUE,stringsAsFactors=FALSE)
?within(dat1,WEIGHT <-
as.numeric(factor(DESTINY,levels=c("FRA","BER","NY","WAS")))*VALUE)


A.K.




On Friday, January 17, 2014 4:15 AM, Mat <matthias.weber at fnt.de> wrote:
Hello together,

i have a little problem, to create a new column, in a data.frame.
I know i can calculate one column with as a example 2 like this:
ORDER$WEIGHT <- ORDER$VALUE * 2

But how can i create the ORDER$WEIGHT with different numbers, like this one.

I have a data.frame like this one:

ORDER?  DESTINY? ? VALUE
A? ? ? ?  NY? ? ? ? ? 100
B? ? ? ?  BER? ? ? ? ? 10
C? ? ? ?  FRA? ? ? ?  100
D? ? ? ?  WAS? ? ? ?  50

I want now the column ORDER$WEIGHT in dependence of "DESTINY". NY
should be
*3, BER *2, FRA*1 and WAS * 4.

The solution look like this one:

ORDER?  DESTINY? ? VALUE?  WEIGHT
A? ? ? ?  NY? ? ? ? ? 100? ? ? ? ? 300
B? ? ? ?  BER? ? ? ? ? 10? ? ? ? ? ?  20
C? ? ? ?  FRA? ? ? ?  100? ? ? ? ? ? 100
D? ? ? ?  WAS? ? ? ?  50? ? ? ? ? ?  200

Maybe anyone can help me, how i can do this?

Thank you.



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View this message in context:
http://r.789695.n4.nabble.com/calculate-an-value-in-dependence-of-another-column-tp4683727.html
Sent from the R help mailing list archive at Nabble.com.

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