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Mohammad Tanvir Ahamed

2015-Apr-06 06:05 UTC

[R] Combine list element by column name to make a dataframe

Hi ,?

I have a example list like follow?


############################################

lst<-list(setNames(c(1,10,50,60,70,80),c("id","id1","math","phy","che","bio")),setNames(c(2,20,45),c("id","id1","phy")),setNames(c(3,30,75),c("id","id1","bio")))


My expected outcome :?

---------------------------------------------------------------------

df<-rbind(c(1,10,50,60,70,80),c(2,20,NA,45,NA,NA),c(3,30,NA,NA,NA,75))

colnames(df)<-c("id","id1","math","phy","che","bio")

row.names(df) <- NULL

df

############################################


Any suggestion will be appreciated .?

Thanks in advance.

?

Best regards


...........................?

Tanvir Ahamed

G?teborg, Sweden




	[[alternative HTML version deleted]]

peter dalgaard

2015-Apr-06 08:41 UTC

head link

[R] Combine list element by column name to make a dataframe

> On 06 Apr 2015, at 08:05 , Mohammad Tanvir Ahamed via R-help <r-help at
r-project.org> wrote:
> 
> Hi ,?
> 
> I have a example list like follow?
> 
> 
> ############################################
> 
>
lst<-list(setNames(c(1,10,50,60,70,80),c("id","id1","math","phy","che","bio")),setNames(c(2,20,45),c("id","id1","phy")),setNames(c(3,30,75),c("id","id1","bio")))
> 
> 
> My expected outcome :?
> 
> ---------------------------------------------------------------------
> 
> df<-rbind(c(1,10,50,60,70,80),c(2,20,NA,45,NA,NA),c(3,30,NA,NA,NA,75))
> 
>
colnames(df)<-c("id","id1","math","phy","che","bio")
> 
> row.names(df) <- NULL
> 
> df
> 
> ############################################
> 
> 
> Any suggestion will be appreciated .?
Hmm, in principle this looks like a merge() problem, if you first convert each
list element to a data frame. That could be painful to get right though.

You could try something like this:
> nm <- Reduce(union, lapply(lst, names)) # or just type it in
> nm[1] "id"   "id1"  "math" "phy" 
"che"  "bio" > blank <- setNames(rep(NA_real_, length(nm)), nm)
> fill1 <- function(x, blank) {blank[names(x)] <- x; blank}
> lapply(lst, fill1, blank)[[1]]
  id  id1 math  phy  che  bio 
   1   10   50   60   70   80 

[[2]]
  id  id1 math  phy  che  bio 
   2   20   NA   45   NA   NA 

[[3]]
  id  id1 math  phy  che  bio 
   3   30   NA   NA   NA   75 
> do.call(rbind,lapply(lst, fill1, blank))     id id1 math phy che bio
[1,]  1  10   50  60  70  80
[2,]  2  20   NA  45  NA  NA
[3,]  3  30   NA  NA  NA  75

(NB, this is a matrix, not a data frame, but so is your "df"!)

Notice that this does not do a proper merge on the id fields, i.e. if you have
two different records with different grades (say one with "che" and
another with "phy") on the same id, you get two records, not one.
However, that might well be what you wanted.

(It is tempting to use 
> fill1 <- function(x) `[<-`(blank, names(x), x)
> lapply(lst, fill1)
which does seem to work, but should probably be avoided because of the risk of
destructive modification.)

> 
> Thanks in advance.
> 
> ?
> 
> Best regards
> 
> 
> ...........................?
> 
> Tanvir Ahamed
> 
> G?teborg, Sweden
> 
> 
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at 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.
-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

Michael Hannon

2015-Apr-06 08:43 UTC

head link

[R] Combine list element by column name to make a dataframe

Maybe something like the appended?

-- Mike

lst <- list(setNames(c(1,10,50,60,70,80),
                    
c("id","id1","math","phy","che","bio")),
            setNames(c(2,20,45),
                     c("id","id1","phy")),
            setNames(c(3,30,75),
                     c("id","id1","bio")))

lst


df <- rbind(c(1,10,50,60,70,80),
            c(2,20,NA,45,NA,NA),
            c(3,30,NA,NA,NA,75))

colnames(df)<-c("id","id1","math","phy","che","bio")
row.names(df) <- NULL

df

allNames <- unique(unlist(lapply(lst, names)))
allNames

newLst <- lapply(lst, function(element) {
    element[allNames]
})
newLst

df2 <- do.call(rbind, newLst)
df2

all.equal(df, df2)

On Sun, Apr 5, 2015 at 11:05 PM, Mohammad Tanvir Ahamed via R-help
<r-help at r-project.org> wrote:> Hi ,
>
> I have a example list like follow
>
>
> ############################################
>
>
lst<-list(setNames(c(1,10,50,60,70,80),c("id","id1","math","phy","che","bio")),setNames(c(2,20,45),c("id","id1","phy")),setNames(c(3,30,75),c("id","id1","bio")))
>
>
> My expected outcome :
>
> ---------------------------------------------------------------------
>
> df<-rbind(c(1,10,50,60,70,80),c(2,20,NA,45,NA,NA),c(3,30,NA,NA,NA,75))
>
>
colnames(df)<-c("id","id1","math","phy","che","bio")
>
> row.names(df) <- NULL
>
> df
>
> ############################################
>
>
> Any suggestion will be appreciated .
>
> Thanks in advance.
>
>
>
> Best regards
>
>
> ...........................
>
> Tanvir Ahamed
>
> G?teborg, Sweden
>
>
>
>
>         [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at 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.

Duncan Mackay

2015-Apr-07 03:33 UTC

head link

[R] Combine list element by column name to make a dataframe

forgot to cc to list

have a look at https://stat.ethz.ch/pipermail/r-help/2012-January/300275.html

and other messages in the sequence

if you use Marc Schwartz's list2df you with have to transpose  it with t()

Duncan

Duncan Mackay
Department of Agronomy and Soil Science
University of New England
Armidale NSW 2351
Email: home: mackay at northnet.com.au

-----Original Message-----
From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Mohammad
Tanvir Ahamed via R-help
Sent: Monday, 6 April 2015 16:06
To: r-help at r-project.org
Subject: [R] Combine list element by column name to make a dataframe

Hi ,?

I have a example list like follow?


############################################

lst<-list(setNames(c(1,10,50,60,70,80),c("id","id1","math","phy","che","bio")),setNames(c(2,20,45),c("id","id1","phy")),setNames(c(3,30,75),c("id","id1","bio")))


My expected outcome :?

---------------------------------------------------------------------

df<-rbind(c(1,10,50,60,70,80),c(2,20,NA,45,NA,NA),c(3,30,NA,NA,NA,75))

colnames(df)<-c("id","id1","math","phy","che","bio")

row.names(df) <- NULL

df

############################################


Any suggestion will be appreciated .?

Thanks in advance.

?

Best regards


...........................?

Tanvir Ahamed

G?teborg, Sweden




	[[alternative HTML version deleted]]

R help - Apr 2015 - Combine list element by column name to make a dataframe

[R] Combine list element by column name to make a dataframe

[R] Combine list element by column name to make a dataframe

[R] Combine list element by column name to make a dataframe

[R] Combine list element by column name to make a dataframe