data frame manipulation with condition

TY Uwe,

So I will have to write a line for each condition? Right?

In fact I was trying to do something with apply in one line, but couldn't achieve any result. In fact, all my transformation will be multiplying one object by a specific number according to the value of df$x.

Arnaud Gaboury
?
A2CT2 Ltd.


-----Original Message-----
From: Uwe Ligges [mailto:ligges at statistik.tu-dortmund.de] 
Sent: vendredi 24 f?vrier 2012 16:33
To: Arnaud Gaboury
Cc: r-help at r-project.org
Subject: Re: [R] data frame manipulation with condition

Dear list,

n00b question, but still can't find any easy answer.

Here is a df:

Change

df<-data.frame(cbind(x=c("AA","BB","CC","AA"),y=1:4))

to

  df <- data.frame(x = c("AA","BB","CC","AA"), y = 1:4)

to make your object a sensible data.frame.

df

    x y
1 AA 1
2 BB 2
3 CC 3
4 AA 4


I want to modify this df this way :
  if df$x=="AA" then df$y=df$y*10

df$y[df$x=="AA"] <- df$y[df$x=="AA"] * 25

...


Uwe Ligges

  if df$x=="BB" then df$y=df$y*25

and so on with other conditions.

TY for any help.

Trading

A2CT2 Ltd.


Arnaud Gaboury

A2CT2 Ltd.

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