r - Splitting a dataframe by column name indices -

this variation of earlier question.

df <- data.frame(matrix(rnorm(9*9), ncol=9)) names(df) <- c("c_1", "d_1", "e_1", "a_p", "b_p", "c_p", "1_o1", "2_o1", "3_o1") 

i want split dataframe index given in column.names after underscore "_". (the indices can character/number in different lengths; these random examples).

indx <- gsub(".*_", "", names(df)) 

and name resulting dataframes accordingly n end 3 dataframes, called:

• df_1
• df_p
• df_o1

thank you!

here, can split column names indx, subset of data within list using lapply , [, set names of list elements using setnames, , use list2env if need them individual datasets (not recommended of operations can done within list , later if want, can saved using write.table lapply.

 list2env(      setnames(        lapply(split(colnames(df), indx), function(x) df[x]),                 paste('df', sort(unique(indx)), sep="_")),                                                envir=.globalenv)   head(df_1,2) #      c_1        d_1        e_1 #1  1.0085829 -0.7219199  0.3502958 #2 -0.9069805 -0.7043354 -1.1974415   head(df_o1,2) #     1_o1      2_o1       3_o1 #1 0.7924930  0.434396  1.7388130 #2 0.9202404 -2.079311 -0.6567794  head(df_p,2) #      a_p       b_p        c_p #1 -0.12392272 -1.183582  0.8176486 #2  0.06330595 -0.659597 -0.6350215 

or using map. similar above approach ie. split column names indx , use [ extract columns, , rest above.

list2env(setnames(map(`[` ,         list(df), split(colnames(df), indx)),           paste('df',unique(sort(indx)), sep="_")), envir=.globalenv) 

update

you can do:

 indx1 <- factor(indx, levels=unique(indx))  split(colnames(df), indx1)