Re: [R] Query - Merging and conditional replacement of values in a data frame

[MacQueen, Don]

How about this?

foo <- merge(df1, df2, all=TRUE)

is.new <- !is.na(foo$v11)
foo$v1[is.new] <- foo$v11[is.new]

foo <- foo[, names(df1)]

> foo
  time  v1 v2 v3
11   2  3  4
22   5  6  4
33 112  3  4
44 112  3  4
55   2  3  4
66   2  3  4


-- 
Don MacQueen

Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062


On 2/11/17, 4:13 PM, "R-help on behalf of Bhaskar Mitra" 
 wrote:

Hello Everyone,

I have two data frames df1 and df2 as shown below. They
are of different length. However, they have one common column - time.

df1 <-
time v1  v2 v3
1 2   3  4
2 5   6  4
3 1   3  4
4 1   3  4
5 2   3  4
6 2   3  4


df2 <-
time v11  v12 v13
3 112   3  4
4 112   3  4

By matching the 'time' column in df1 and df2, I am trying to modify column
'v1' in df1 by replacing it
with values in column 'v11' in df2. The modified df1 should look something
like this:

df1 <-
time v1   v2 v3
1 2   3  4
2 5   6  4
3 112 3  4
4 112 3  4
5 2   3  4
6 2   3  4

I tried to use the 'merge' function to combine df1 and df2 followed by
the conditional 'ifelse' statement. However, that doesn't seem to work.

Can I replace the values in df1 by not merging the two data frames?

Thanks for your help,

Regards,
Bhaskar

[[alternative HTML version deleted]]

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Re: [R] Query - Merging and conditional replacement of values in a data frame

[Bhaskar Mitra]

Thanks for all your help. This is helpful.

Best,
Bhaskar

On Sun, Feb 12, 2017 at 4:35 AM, Jim Lemon  wrote:

> Hi Bhaskar,
> Maybe:
>
> df1 <-read.table(text="time v1  v2 v3
> 1 2   3  4
> 2 5   6  4
> 3 1   3  4
> 4 1   3  4
> 5 2   3  4
> 6 2   3  4",
> header=TRUE)
>
>
> df2 <-read.table(text="time v11  v12 v13
> 3 112   3  4
> 4 112   3  4",
> header=TRUE)
>
> for(time1 in df1$time) {
>  time2<-which(df2$time==time1)
>  if(length(time2)) df1[df1$time==time1,]<-df2[time2,]
> }
>
> Jim
>
>
> On Sun, Feb 12, 2017 at 11:13 AM, Bhaskar Mitra
>  wrote:
> > Hello Everyone,
> >
> > I have two data frames df1 and df2 as shown below. They
> > are of different length. However, they have one common column - time.
> >
> > df1 <-
> > time v1  v2 v3
> > 1 2   3  4
> > 2 5   6  4
> > 3 1   3  4
> > 4 1   3  4
> > 5 2   3  4
> > 6 2   3  4
> >
> >
> > df2 <-
> > time v11  v12 v13
> > 3 112   3  4
> > 4 112   3  4
> >
> > By matching the 'time' column in df1 and df2, I am trying to modify
> column
> > 'v1' in df1 by replacing it
> > with values in column 'v11' in df2. The modified df1 should look
> something
> > like this:
> >
> > df1 <-
> > time v1   v2 v3
> > 1 2   3  4
> > 2 5   6  4
> > 3 112 3  4
> > 4 112 3  4
> > 5 2   3  4
> > 6 2   3  4
> >
> > I tried to use the 'merge' function to combine df1 and df2 followed by
> > the conditional 'ifelse' statement. However, that doesn't seem to work.
> >
> > Can I replace the values in df1 by not merging the two data frames?
> >
> > Thanks for your help,
> >
> > Regards,
> > Bhaskar
> >
> > [[alternative HTML version deleted]]
> >
> > __
> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
>

[[alternative HTML version deleted]]

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Re: [R] Query - Merging and conditional replacement of values in a data frame

[Jim Lemon]

Hi Bhaskar,
Maybe:

df1 <-read.table(text="time v1  v2 v3
1 2   3  4
2 5   6  4
3 1   3  4
4 1   3  4
5 2   3  4
6 2   3  4",
header=TRUE)


df2 <-read.table(text="time v11  v12 v13
3 112   3  4
4 112   3  4",
header=TRUE)

for(time1 in df1$time) {
 time2<-which(df2$time==time1)
 if(length(time2)) df1[df1$time==time1,]<-df2[time2,]
}

Jim


On Sun, Feb 12, 2017 at 11:13 AM, Bhaskar Mitra
 wrote:
> Hello Everyone,
>
> I have two data frames df1 and df2 as shown below. They
> are of different length. However, they have one common column - time.
>
> df1 <-
> time v1  v2 v3
> 1 2   3  4
> 2 5   6  4
> 3 1   3  4
> 4 1   3  4
> 5 2   3  4
> 6 2   3  4
>
>
> df2 <-
> time v11  v12 v13
> 3 112   3  4
> 4 112   3  4
>
> By matching the 'time' column in df1 and df2, I am trying to modify column
> 'v1' in df1 by replacing it
> with values in column 'v11' in df2. The modified df1 should look something
> like this:
>
> df1 <-
> time v1   v2 v3
> 1 2   3  4
> 2 5   6  4
> 3 112 3  4
> 4 112 3  4
> 5 2   3  4
> 6 2   3  4
>
> I tried to use the 'merge' function to combine df1 and df2 followed by
> the conditional 'ifelse' statement. However, that doesn't seem to work.
>
> Can I replace the values in df1 by not merging the two data frames?
>
> Thanks for your help,
>
> Regards,
> Bhaskar
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

__
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and provide commented, minimal, self-contained, reproducible code.

Re: [R] Query - Merging and conditional replacement of values in a data frame

[Jeff Newmiller]

Or use rownames and subscripting?

df1 <- read.table( text=
"time v1  v2 v3
1 2   3  4
2 5   6  4
3 1   3  4
4 1   3  4
5 2   3  4
6 2   3  4
",header=TRUE)

df2 <- read.table( text=
"time v11  v12 v13
3 112   3  4
4 112   3  4
",header=TRUE)

df3 <- df1
rownames( df3 ) <- df3$time
df3[ as.character( df2$time ), "v1" ] <- df2[ , "v11" ]
df3
df3[ "7", c( "time", "v1" ) ] <- data.frame( time=7, v1=2 )
df3
df2b <- data.frame( time=c(7,8), v2=c(4,5), v3=c(6,7) )
df2b
df3[ df2b$time, c( "time", "v2", "v3" ) ] <- df2b
df3

On Sat, 11 Feb 2017, Bert Gunter wrote:


Your "assignments" (<-) are not legitimate R code that can be cut and
pasted. Learn to use dput() to provide examples that we can use.

You fail to say whether the time column of df2 is a proper subset of
df1 or may contain times not in df1. I shall assume the latter. You
also did not say whether the time values occur in order in both data
frames. I shall assume they do not.

If I understand correctly,then,  match and subscripting will do it,
something like



df1 <-data.frame(time = 1:6, v1 = c(2,5,1,1,2,2))
df2 <- data.frame(time = 4:3,v11 = c(112,113))



wm <- match(df1$time,df2$time)
df1[!is.na(wm),"v1"] <- df2[na.omit(wm),"v11"]



df1


 time  v1
11   2
22   5
33 113
44 112
55   2
66   2

Cheers,
Bert





Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Sat, Feb 11, 2017 at 4:13 PM, Bhaskar Mitra
 wrote:

Hello Everyone,

I have two data frames df1 and df2 as shown below. They
are of different length. However, they have one common column - time.

df1 <-
time v1  v2 v3
1 2   3  4
2 5   6  4
3 1   3  4
4 1   3  4
5 2   3  4
6 2   3  4


df2 <-
time v11  v12 v13
3 112   3  4
4 112   3  4

By matching the 'time' column in df1 and df2, I am trying to modify column
'v1' in df1 by replacing it
with values in column 'v11' in df2. The modified df1 should look something
like this:

df1 <-
time v1   v2 v3
1 2   3  4
2 5   6  4
3 112 3  4
4 112 3  4
5 2   3  4
6 2   3  4

I tried to use the 'merge' function to combine df1 and df2 followed by
the conditional 'ifelse' statement. However, that doesn't seem to work.

Can I replace the values in df1 by not merging the two data frames?

Thanks for your help,

Regards,
Bhaskar

[[alternative HTML version deleted]]

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


__
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and provide commented, minimal, self-contained, reproducible code.



---
Jeff NewmillerThe .   .  Go Live...
DCN:Basics: ##.#.   ##.#.  Live Go...
  Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/BatteriesO.O#.   #.O#.  with
/Software/Embedded Controllers)   .OO#.   .OO#.  rocks...1k

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Re: [R] Query - Merging and conditional replacement of values in a data frame

[Bert Gunter]

Your "assignments" (<-) are not legitimate R code that can be cut and
pasted. Learn to use dput() to provide examples that we can use.

You fail to say whether the time column of df2 is a proper subset of
df1 or may contain times not in df1. I shall assume the latter. You
also did not say whether the time values occur in order in both data
frames. I shall assume they do not.

If I understand correctly,then,  match and subscripting will do it,
something like


> df1 <-data.frame(time = 1:6, v1 = c(2,5,1,1,2,2))
> df2 <- data.frame(time = 4:3,v11 = c(112,113))

> wm <- match(df1$time,df2$time)
> df1[!is.na(wm),"v1"] <- df2[na.omit(wm),"v11"]

> df1

  time  v1
11   2
22   5
33 113
44 112
55   2
66   2

Cheers,
Bert





Bert Gunter

"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Sat, Feb 11, 2017 at 4:13 PM, Bhaskar Mitra
 wrote:
> Hello Everyone,
>
> I have two data frames df1 and df2 as shown below. They
> are of different length. However, they have one common column - time.
>
> df1 <-
> time v1  v2 v3
> 1 2   3  4
> 2 5   6  4
> 3 1   3  4
> 4 1   3  4
> 5 2   3  4
> 6 2   3  4
>
>
> df2 <-
> time v11  v12 v13
> 3 112   3  4
> 4 112   3  4
>
> By matching the 'time' column in df1 and df2, I am trying to modify column
> 'v1' in df1 by replacing it
> with values in column 'v11' in df2. The modified df1 should look something
> like this:
>
> df1 <-
> time v1   v2 v3
> 1 2   3  4
> 2 5   6  4
> 3 112 3  4
> 4 112 3  4
> 5 2   3  4
> 6 2   3  4
>
> I tried to use the 'merge' function to combine df1 and df2 followed by
> the conditional 'ifelse' statement. However, that doesn't seem to work.
>
> Can I replace the values in df1 by not merging the two data frames?
>
> Thanks for your help,
>
> Regards,
> Bhaskar
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.

[R] Query - Merging and conditional replacement of values in a data frame

[Bhaskar Mitra]

Hello Everyone,

I have two data frames df1 and df2 as shown below. They
are of different length. However, they have one common column - time.

df1 <-
time v1  v2 v3
1 2   3  4
2 5   6  4
3 1   3  4
4 1   3  4
5 2   3  4
6 2   3  4


df2 <-
time v11  v12 v13
3 112   3  4
4 112   3  4

By matching the 'time' column in df1 and df2, I am trying to modify column
'v1' in df1 by replacing it
with values in column 'v11' in df2. The modified df1 should look something
like this:

df1 <-
time v1   v2 v3
1 2   3  4
2 5   6  4
3 112 3  4
4 112 3  4
5 2   3  4
6 2   3  4

I tried to use the 'merge' function to combine df1 and df2 followed by
the conditional 'ifelse' statement. However, that doesn't seem to work.

Can I replace the values in df1 by not merging the two data frames?

Thanks for your help,

Regards,
Bhaskar

[[alternative HTML version deleted]]

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.