Combine/merge multiple data frames by element names

Question

I have data frames generated by lapply with distinct element names.

head(df1)

$Sample1

     G1         G2      Group
1 1.016673 -1.04402692   1
2 1.019958 -0.86763046   1
3 1.033050 -1.09717438   1
4 1.036969  0.26971351   1
5 1.044059  1.73402959   1

$Sample2

     G1         G2      Group
1 1.413218  0.22466456   1
2 1.413339 -0.91755436   1
3 1.415782 -0.23471118   1
4 1.434750 -0.77498973   1
5 1.436905  0.76642626   1

Another set is similar in format, specified by 2 under Group

head(df2)

$Sample1

     G1         G2      Group
1 1.053269 -1.04460950   2
2 1.059461 -0.86711232   2
3 1.072446 -1.09748431   2
4 1.078763  0.26785751   2
5 1.038325  1.73818175   2

$Sample2

     G1         G2      Group
1 1.438067  0.22933986   2
2 1.856085 -0.91988726   2
3 1.415782 -0.23405677   2
4 1.434750 -0.77406530   2
5 1.436905  0.76078091   2

My goal is to combine/merge them together by element names, for example Sample1 and Sample2.

$Sample1

     G1         G2      Group
1 1.016673 -1.04402692   1
2 1.019958 -0.86763046   1
3 1.033050 -1.09717438   1
4 1.036969  0.26971351   1
5 1.044059  1.73402959   1
1 1.053269 -1.04460950   2
2 1.059461 -0.86711232   2
3 1.072446 -1.09748431   2
4 1.078763  0.26785751   2
5 1.038325  1.73818175   2

$Sample2

     G1         G2      Group
1 1.413218  0.22466456   1
2 1.413339 -0.91755436   1
3 1.415782 -0.23471118   1
4 1.434750 -0.77498973   1
5 1.436905  0.76642626   1
1 1.438067  0.22933986   2
2 1.856085 -0.91988726   2
3 1.415782 -0.23405677   2
4 1.434750 -0.77406530   2
5 1.436905  0.76078091   2

I could not figure out how to do this. Could someone help me? Thanks!

Answer 1

Maybe try mapply and rbind:

a1 <- list(mtcars[1:5,],mtcars[6:10,])
a2 <- list(mtcars[11:15,],mtcars[16:20,])
> mapply(FUN = rbind,a1,a2,SIMPLIFY = FALSE)
[[1]]
                    mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Mazda RX4          21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
Mazda RX4 Wag      21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
Datsun 710         22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
Hornet 4 Drive     21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
Hornet Sportabout  18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
Merc 280C          17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
Merc 450SE         16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
Merc 450SL         17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
Merc 450SLC        15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
Cadillac Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4

[[2]]
                     mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1

Equivalently (I think) in purrr would be map2(a1,a2,rbind).