Merge/Join one data frame (X) to multiple data frames separately

Question

Let us say that we have some data frames named S1,S2,S3... that I want to join independently by column names to dataframe X. This is how they look like:

S1 <- data.frame(
  values = c (1:5), 
  numbers = c(11:15))
S1


S2 <- data.frame(
  values = c (1:5), 
  numbers = c(11:15))
S2


S3 <- data.frame(
  values = c (1:5), 
  numbers = c(16:20))
S3

#Dataframe X

X <- data.frame(
  values = c (26:30), 
  numbers = c(501:505))
X

S1
S2
S3
X

Using rbind, it is really easy to merge/join them according to column names. As below:

S1_X<- rbind(S1,X)

S1_X


S2_X<- rbind(S2,X)

S2_X


S3_X<- rbind(S3,X)

S3_X

Now the problem is that I have 500 plus data frames (S1,S2,S3,S4,S5.....S500) that I want to join to dataframe "X" by any function. For example rbind. Is it possible to use some loop/function for that.

What I have best tried is create a list (nested list of dataframes) that I can later split into individual dataframes:

output = lapply(list(S1=S1,S2=S2,S3=S3),rbind,X)

The output is what I expected. So it works The only problem is, how do I specify S1 to S500?

Thank you in advance!

Answer 1

You can use For Loop here. Here I have created code using your algorithm, first created a list of merged dataframes and then split the list into separate dataframes.

S1 <- data.frame(values = c (1:5), numbers = c(11:15))
S2 <- data.frame(values = c (1:5), numbers = c(11:15))
S3 <- data.frame(values = c (1:5), numbers = c(16:20))
#Dataframe X
X <- data.frame(values = c (26:30), numbers = c(501:505))

#defining a NULL object
S=NULL
#creating a list of merged dataframes
for (i in 1:3){
S[i] = list(rbind(get(paste("S",i,sep='')),X))
names(S)[i] = paste("S",i,"_X",sep='')}

#extracting dataframes
for(i in 1:3){
assign(paste("S",i,"_X",sep = ""),S[[i]])
}