[R] data frame manipulation with condition

Fri Feb 24 18:52:55 CET 2012

In fact I need to use William tip: Use mult[as.character(df$x)] instead of mult[df$x].

Let's try again with a shorter df as example:

The rule: if AA, then multiply y by 2, if BB multiply y by 5, if CC do nothing, if DD multiply by 2.

Let's say day 1 I have df1:

df1 <-
structure(list(x = structure(c(1L, 2L, 2L, 3L), .Label = c("AA", 
"BB", "CC"), class = "factor"), y = 1:4), .Names = c("x", "y"
), row.names = c(NA, -4L), class = "data.frame")

> df1
   x y
1 AA 1
2 BB 2
3 BB 3
4 CC 4

>mult <- c("AA"=2,"BB"=5,"CC"=1,"DD"=2)
>df1$y <- df1$y * mult[as.character(df1$x)]
> df1
   x  y
1 AA  2
2 BB 10
3 BB 15
4 CC  4

WORKING

Now day 2 with df2:

>df2 <- data.frame(x = c("AA","AA","BB","BB","BB","CC","DD","DD"), y = 1:8)
>df2$y <- df2$y * mult[as.character(df2$x)]
> df2
   x  y
1 AA  2
2 AA  4
3 BB 15
4 BB 20
5 BB 25
6 CC  6
7 DD 14
8 DD 16

WORKING

Ty both of you and have a good weekend.

Arnaud Gaboury

A2CT2 Ltd.

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Arnaud Gaboury
Sent: vendredi 24 février 2012 18:17
To: Sarah Goslee
Cc: r-help at r-project.org
Subject: Re: [R] data frame manipulation with condition

TY very much Sarah: your tip is doing the job:

reported <-
structure(list(Product = structure(c(1L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 5L, 5L, 5L, 6L, 7L, 7L, 8L, 8L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 10L, 10L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 12L, 12L, 13L, 14L, 14L), .Label = c("CL", "Cocoa", "Coffee C", "GC", "HG", "HO", "NG", "PL", "RB", "SI", "Sugar No 11", "ZC", "ZL", "ZW"), class = "factor"), reported.Price = c(105.35, 2380, 2407, 2408, 202.35, 202.8, 202.95, 205.85, 206.05, 206.1, 206.2, 1748, 378.8, 379.25, 379.5, 320.61, 2.538, 2.543, 1669, 1678.5, 304.49, 321.39, 321.6, 321.65, 322.5, 322.55, 322.8, 323.04, 3390, 3397.5, 24.16, 24.2, 24.22, 24.23, 24.54, 25.5, 25.55, 631.75, 638, 53.77, 630.75, 633), reported.Nbr.Lots = c(6L, 3L, -1L, -2L, -40L, -1L, -1L, 10L, 5L, 6L, 19L, 17L, 23L, 12L, 35L, 11L, -54L, -52L, 26L, 26L, 10L, -10L, 1L, 4L, 4L, 1L, 5L, 5L, 17L, 17L, 114L, 71L, 16L, 27L, -3L, 3L, -3L, -89L, -1L, -1L, -51L, -51L)), .Names = c("Product", "reported.Price", "reported.Nbr.Lots"
), row.names = c(7L, 4L, 5L, 6L, 13L, 14L, 15L, 16L, 17L, 18L, 19L, 8L, 9L, 10L, 11L, 12L, 20L, 21L, 22L, 23L, 35L, 36L, 37L, 38L, 39L, 40L, 41L, 42L, 31L, 32L, 24L, 25L, 26L, 27L, 28L, 29L, 30L, 2L, 3L, 1L, 33L, 34L), class = "data.frame")

> mult<-c(CL=100,GC=10,HG=10,NG=1000,PL=10,RB=100,SI=10,ZL=100,HO=100,KC
> =1,CC=1,SB=1,ZC=1,ZW=1) reported$reported.Price <- 
> reported$reported.Price * mult[reported$Product]

reported <-
structure(list(Product = structure(c(1L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 5L, 5L, 5L, 6L, 7L, 7L, 8L, 8L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 9L, 10L, 10L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 12L, 12L, 13L, 14L, 14L), .Label = c("CL", "Cocoa", "Coffee C", "GC", "HG", "HO", "NG", "PL", "RB", "SI", "Sugar No 11", "ZC", "ZL", "ZW"), class = "factor"), reported.Price = c(10535, 23800, 24070, 24080, 2023.5, 2028, 2029.5, 2058.5, 2060.5, 2061, 2062, 1748000, 3788, 3792.5, 3795, 32061, 25.38, 25.43, 166900, 167850, 30449, 32139, 32160, 32165, 32250, 32255, 32280, 32304, 3390, 3397.5, 24.16, 24.2, 24.22, 24.23, 24.54, 25.5, 25.55, 631.75, 638, 53.77, 630.75, 633), reported.Nbr.Lots = c(6L, 3L, -1L, -2L, -40L, -1L, -1L, 10L, 5L, 6L, 19L, 17L, 23L, 12L, 35L, 11L, -54L, -52L, 26L, 26L, 10L, -10L, 1L, 4L, 4L, 1L, 5L, 5L, 17L, 17L, 114L, 71L, 16L, 27L, -3L, 3L, -3L, -89L, -1L, -1L, -51L, -51L)), .Names = c("Product", "reported.Price", "reported.Nbr.Lots"
), row.names = c(7L, 4L, 5L, 6L, 13L, 14L, 15L, 16L, 17L, 18L, 19L, 8L, 9L, 10L, 11L, 12L, 20L, 21L, 22L, 23L, 35L, 36L, 37L, 38L, 39L, 40L, 41L, 42L, 31L, 32L, 24L, 25L, 26L, 27L, 28L, 29L, 30L, 2L, 3L, 1L, 33L, 34L), class = "data.frame")

Have a good weekend.

Arnaud Gaboury

A2CT2 Ltd.
Trade: +41 22 849 88 63
Fax:   +41 22 849 88 66
arnaud.gaboury at a2ct2.com 

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-----Original Message-----
From: Sarah Goslee [mailto:sarah.goslee at gmail.com]
Sent: vendredi 24 février 2012 17:54
To: Arnaud Gaboury
Cc: r-help at r-project.org
Subject: Re: [R] data frame manipulation with condition

You need, as I already suggested, to use a value of 1 for levels you don't want to change.

> mult <- c(AA = 10, BB = 25, CC=1, DD=15) mult[df$x]
AA BB CC AA DD DD
10 25  1 10 15 15
> df$y * mult[df$x]
AA BB CC AA DD DD
10 50  3 40 75 90

On Fri, Feb 24, 2012 at 11:36 AM, Arnaud Gaboury <arnaud.gaboury at a2ct2.com> wrote:
>> df<- data.frame(x = c("AA","BB","CC","AA","DD","DD"), y = 1:6) mult
>> <- c(AA = 10, BB = 25,DD=15) df$y <- df$y * mult[df$x] df
>   x  y
> 1 AA 10
> 2 BB 50
> 3 CC 45
> 4 AA 40
> 5 DD NA
> 6 DD NA
>
> My df is in fact much more longer than the chosen example shown here. It seems your tip didn't do the job.
> I am expecting this as result :
>
>> df
>   x  y
> 1 AA 10  ----> if df$x==AA, df$y<-1*10
> 2 BB 50   ----> if df$x==BB, df$y<-2*25
> 3 CC 3         NOTHING
> 4 AA 40    ----> if df$x==AA, df$y<-4*10
> 5 DD 75   ----> if df$x==DD, df$y<-5*15
> 6 DD 90   ----> if df$x==DD, df$y<-6*15
>
> Arnaud Gaboury
>
> A2CT2 Ltd.
>
> -----Original Message-----
> From: Uwe Ligges [mailto:ligges at statistik.tu-dortmund.de]
> Sent: vendredi 24 février 2012 17:07
> To: Arnaud Gaboury
> Cc: r-help at r-project.org
> Subject: Re: [R] data frame manipulation with condition
>
>
>
> On 24.02.2012 16:59, Arnaud Gaboury wrote:
>> TY Uwe,
>>
>> So I will have to write a line for each condition? Right?
>>
>> In fact I was trying to do something with apply in one line, but couldn't achieve any result. In fact, all my transformation will be multiplying one object by a specific number according to the value of df$x.
>
> In that case:
>
> mult <- c(AA = 10, BB = 25)
>
> Then:
>
>
> df$y <- df$y * mult[df$x]
>
>
> Uwe Ligges
>
>
>>
>> Arnaud Gaboury
>>
>> A2CT2 Ltd.
>>
>>
>> -----Original Message-----
>> From: Uwe Ligges [mailto:ligges at statistik.tu-dortmund.de]
>> Sent: vendredi 24 février 2012 16:33
>> To: Arnaud Gaboury
>> Cc: r-help at r-project.org
>> Subject: Re: [R] data frame manipulation with condition
>>
>>
>>
>> On 24.02.2012 16:25, Arnaud Gaboury wrote:
>>> Dear list,
>>>
>>> n00b question, but still can't find any easy answer.
>>>
>>> Here is a df:
>>
>>
>> Change
>>
>>>> df<-data.frame(cbind(x=c("AA","BB","CC","AA"),y=1:4))
>>
>> to
>>
>>    df<- data.frame(x = c("AA","BB","CC","AA"), y = 1:4)
>>
>> to make your object a sensible data.frame.
>>
>>
>>
>>>> df
>>>      x y
>>> 1 AA 1
>>> 2 BB 2
>>> 3 CC 3
>>> 4 AA 4
>>>
>>>
>>> I want to modify this df this way :
>>>    if df$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
>>
>>
--
Sarah Goslee
http://www.functionaldiversity.org

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