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Replace values ​​in data.frame with values ​​from another data.frame

So I have this data.frame, call it df1, which looks like this:

   r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12
1   1  2  2  2  0  2  1  2  0   2   1   2
2   0  2  2  2  2  2  0  2  0   2   2   2
3   1  2  2  2  0  2  2  2  2   1   2   2
4   1  2  2  2  2  1  2  2  2   1   2   2
5   0  1  2  2  0  2  1  0  0   1   1   0
6   0  2  0  2  0  2  2  0  0   2   2   2
7   1  2  2  2  2  2  2  0  0   1   2   2
8   0  2  2  2  2  2  2  2  2   2   2   2
9   0  2  2  2  2  2  1  1  1   1   1   2

and one, let's call it df2, which looks like this:

         r1         r2             r3             r4            r5 ...
1 arp1_base melo1_base      son_clave     melo2_base   melo3_major ...
2   arp1_v1   melo1_v1    rumba_clave melo2_staccato   melo3_minor ...
3   arp1_v2   melo1_v2 rumba_clave_v1  melo2_contour melo3_contour ...

I am not inserting all columns here, but you get the idea (and yes, the number of rows is different).

Now I need to replace the numbers in each column of the first data.frame with the value from the second data.frame corresponding to the column and using the numbers in the first data.frame as the row index for the second data. Frame. I would like to have a new data.frame that looks like this:

         r1         r2             r3 ...
1   arp1_v1   melo1_v2 rumba_clave_v1 ...
2 arp1_base   melo1_v2 rumba_clave_v1 ...
3   arp1_v1   melo1_v2 rumba_clave_v1 ...
.         .          .              .
.         .          .              .
.         .          .              .

How should I do it? Ideally, each new column will be a factor that stores the three names as levels.

And by the way, I feel like this is sort of an FAQ, but I ran into the usual n00b problem with no idea what to do with Google. Is there some magic around this?

EDIT As suggested by @akrun below I can do df1[] <- Map(function(x, y) factor(y[x+1]), df1, df2)

and I get almost what I want in the sense that the columns df1

are now factors with substituted values, but I need each of these factors to have as levels all the values ​​from corresponding column in df2

.

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1 answer


Try

  df1[] <- Map(function(x, y) y[x+1], df1, df2)
  df1
  #       r1       r2             r3            r4            r5
  #1   arp1_v1 melo1_v2 rumba_clave_v1 melo2_contour   melo3_major
  #2 arp1_base melo1_v2 rumba_clave_v1 melo2_contour melo3_contour
  #3   arp1_v1 melo1_v2 rumba_clave_v1 melo2_contour   melo3_major
  #4   arp1_v1 melo1_v2 rumba_clave_v1 melo2_contour melo3_contour
  #5 arp1_base melo1_v1 rumba_clave_v1 melo2_contour   melo3_major
  #6 arp1_base melo1_v2      son_clave melo2_contour   melo3_major
  #7   arp1_v1 melo1_v2 rumba_clave_v1 melo2_contour melo3_contour
  #8 arp1_base melo1_v2 rumba_clave_v1 melo2_contour melo3_contour
  #9 arp1_base melo1_v2 rumba_clave_v1 melo2_contour melo3_contour

Update

To create columns as factor

with levels equal to the levels

corresponding columnsdf2 



  df1[] <-  Map(function(x, y) factor(y[x+1], levels=unique(y)), df1, df2)
  levels(df1[,1])
  #[1] "arp1_base" "arp1_v1"   "arp1_v2"

data

 df1 <- structure(list(r1 = c(1L, 0L, 1L, 1L, 0L, 0L, 1L, 0L, 0L), r2 = c(2L, 
 2L, 2L, 2L, 1L, 2L, 2L, 2L, 2L), r3 = c(2L, 2L, 2L, 2L, 2L, 0L, 
 2L, 2L, 2L), r4 = c(2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), r5 = c(0L, 
 2L, 0L, 2L, 0L, 0L, 2L, 2L, 2L)), .Names = c("r1", "r2", "r3", 
 "r4", "r5"), class = "data.frame", row.names = c("1", "2", "3", 
 "4", "5", "6", "7", "8", "9"))

 df2 <- structure(list(r1 = c("arp1_base", "arp1_v1", "arp1_v2"), 
  r2 = c("melo1_base", "melo1_v1", "melo1_v2"), r3 = c("son_clave",
  "rumba_clave", "rumba_clave_v1"), r4 = c("melo2_base", "melo2_staccato",
  "melo2_contour"), r5 = c("melo3_major","melo3_minor", "melo3_contour")),
 .Names = c("r1", "r2", "r3", "r4", "r5"), class = "data.frame", 
 row.names = c("1", "2", "3"))
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