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How to combine lists of data frames in R?
If we have a list of data frames and the size of those data frames is same then we might want to combine the lists so that the data frames can be combined. This can be done by using mapply function along with cbind. For example, if we have two lists of data frames defined as List1 and List2 then we can combine them using the command −
mapply(cbind,List1,List2,SIMPLIFY=FALSE).
Example
Consider the below data frame −
> x1<-rnorm(10) > x2<-rnorm(10) > df1<-data.frame(x1,x2) > df1
Output
x1 x2 1 0.2378371 0.51433808 2 0.0638975 -1.66077353 3 0.3987209 0.68480587 4 -1.1321073 0.29528261 5 -0.5603269 1.14556819 6 2.2072545 -1.20718355 7 0.8196423 0.38380242 8 -2.2394064 0.06741712 9 -0.7356725 -1.46968026 10 -1.4642820 -1.39423679
Example
> y1<-rnorm(10) > y2<-rnorm(10) > df2<-data.frame(y1,y2) > df2
Output
y1 y2 1 2.2307515 0.375538934 2 -1.3539616 -0.169574915 3 -0.1332480 -0.788416414 4 1.3181498 1.887995737 5 -1.4384012 1.261034365 6 0.3725585 -0.493219141 7 -0.7806511 -1.177616450 8 -0.4772392 0.250962895 9 -0.8932982 -0.004567268 10 0.2224190 -0.203232106
Example
> List1<-list(df1,df2) > List1
Output
[[1]] x1 x2 1 0.2378371 0.51433808 2 0.0638975 -1.66077353 3 0.3987209 0.68480587 4 -1.1321073 0.29528261 5 -0.5603269 1.14556819 6 2.2072545 -1.20718355 7 0.8196423 0.38380242 8 -2.2394064 0.06741712 9 -0.7356725 -1.46968026 10 -1.4642820 -1.39423679 [[2]] y1 y2 1 2.2307515 0.375538934 2 -1.3539616 -0.169574915 3 -0.1332480 -0.788416414 4 1.3181498 1.887995737 5 -1.4384012 1.261034365 6 0.3725585 -0.493219141 7 -0.7806511 -1.177616450 8 -0.4772392 0.250962895 9 -0.8932982 -0.004567268 10 0.2224190 -0.203232106
List2
Example
> a1<-rnorm(10) > a2<-rnorm(10) > df3<-data.frame(a1,a2) > df3
Output
a1 a2 1 1.5711728 0.2861241 2 0.8062374 0.9469154 3 1.1505496 -0.5894829 4 0.9164866 -0.3137043 5 -1.3424446 -1.2921698 6 -0.1499540 -0.8940665 7 -0.1498557 -1.1361156 8 0.9299988 0.7679135 9 -1.7079005 -0.7099908 10 0.8146867 1.3921303
Example
> b1<-rnorm(10) > b2<-rnorm(10) > df4<-data.frame(b1,b2) > df4
Output
b1 b2 1 -1.7113866 1.7014637 2 -0.0202485 1.2428109 3 -0.3892979 -1.5831333 4 0.2127277 -0.4943695 5 -0.4846616 1.0283278 6 -1.4116239 -1.4882983 7 -0.1737286 -0.1101114 8 1.4613389 0.1531942 9 -0.1573986 0.3431330 10 -0.2782074 0.5439397
Example
> List2<-list(df3,df4) > List2
Output
[[1]] a1 a2 1 1.5711728 0.2861241 2 0.8062374 0.9469154 3 1.1505496 -0.5894829 4 0.9164866 -0.3137043 5 -1.3424446 -1.2921698 6 -0.1499540 -0.8940665 7 -0.1498557 -1.1361156 8 0.9299988 0.7679135 9 -1.7079005 -0.7099908 10 0.8146867 1.3921303 [[2]] b1 b2 1 -1.7113866 1.7014637 2 -0.0202485 1.2428109 3 -0.3892979 -1.5831333 4 0.2127277 -0.4943695 5 -0.4846616 1.0283278 6 -1.4116239 -1.4882983 7 -0.1737286 -0.1101114 8 1.4613389 0.1531942 9 -0.1573986 0.3431330 10 -0.2782074 0.5439397
Combining the list of data frames −
Example
> mapply(cbind,List1,List2,SIMPLIFY=FALSE)
Output
[[1]] x1 x2 a1 a2 1 0.2378371 0.51433808 1.5711728 0.2861241 2 0.0638975 -1.66077353 0.8062374 0.9469154 3 0.3987209 0.68480587 1.1505496 -0.5894829 4 -1.1321073 0.29528261 0.9164866 -0.3137043 5 -0.5603269 1.14556819 -1.3424446 -1.2921698 6 2.2072545 -1.20718355 -0.1499540 -0.8940665 7 0.8196423 0.38380242 -0.1498557 -1.1361156 8 -2.2394064 0.06741712 0.9299988 0.7679135 9 -0.7356725 -1.46968026 -1.7079005 -0.7099908 10 -1.4642820 -1.39423679 0.8146867 1.3921303 [[2]] y1 y2 b1 b2 1 2.2307515 0.375538934 -1.7113866 1.7014637 2 -1.3539616 -0.169574915 -0.0202485 1.2428109 3 -0.1332480 -0.788416414 -0.3892979 -1.5831333 4 1.3181498 1.887995737 0.2127277 -0.4943695 5 -1.4384012 1.261034365 -0.4846616 1.0283278 6 0.3725585 -0.493219141 -1.4116239 -1.4882983 7 -0.7806511 -1.177616450 -0.1737286 -0.1101114 8 -0.4772392 0.250962895 1.4613389 0.1531942 9 -0.8932982 -0.004567268 -0.1573986 0.3431330 10 0.2224190 -0.203232106 -0.2782074 0.5439397
Updated on: 02-Jan-2021
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