dplyr::mutate() not working as expected

[tlg265]

Loading some necessary libraries:

library("dplyr")

printf = function(...) cat(sprintf(...))

myeval = function(code, envir = NULL) {
  eval(parse(text = code), envir = envir)
}

Running a very simple experiment:

dataset = data.frame(
  altitude = as.double(c(18.172164, 23.217744, 26.650505, 37.851856, 26.627905)),
  x1 = as.integer(c(15, 39, 1, 73, 8)),
  x2 = as.integer(c(35, 52, 65, 60, 51)),
  zip = as.factor(c("10204", "10406", "10107", "10807", "10106"))
)
dataset

##   altitude x1 x2   zip
## 1 18.17216 15 35 10204
## 2 23.21774 39 52 10406
## 3 26.65050  1 65 10107
## 4 37.85186 73 60 10807
## 5 26.62790  8 51 10106

encoding = data.frame(
  encoding = c(39.1, 38.2, 37.3, 36.4, 35.5),
  row.names = c("10204", "10406", "10107", "10807", "10106")
)
encoding

##       encoding
## 10204     39.1
## 10406     38.2
## 10107     37.3
## 10807     36.4
## 10106     35.5

I think something is wrong here:

varname = "zip" # it is a requirement that this value gets passed as a string
dataset_encoded = myeval(
  sprintf('dataset %%>%% mutate(%s_encoded = encoding[%s, "encoding"])', varname, varname),
  envir = environment()
)
printf("After running the code above, I get the follwoing:\n")

## After running the code above, I get the follwoing:

dataset_encoded

##   altitude x1 x2   zip zip_encoded
## 1 18.17216 15 35 10204        37.3
## 2 23.21774 39 52 10406        36.4
## 3 26.65050  1 65 10107        38.2
## 4 37.85186 73 60 10807        35.5
## 5 26.62790  8 51 10106        39.1

Expected result: (according to the encoding we got earlier)

##   altitude x1 x2   zip zip_encoded
## 1 18.17216 15 35 10204        39.1
## 2 23.21774 39 52 10406        38.2
## 3 26.65050  1 65 10107        37.3
## 4 37.85186 73 60 10807        36.4
## 5 26.62790  8 51 10106        35.5

My Question:

Do you know what is wrong on the mutate sentence above?

Thanks!

[tlg265]

Just found the solution. Had to add as.character(...) as follows:

from:

sprintf('dataset %%>%% mutate(%s_encoded = encoding[%s, "encoding"])', varname, varname)

to:

sprintf('dataset %%>%% mutate(%s_encoded = encoding[as.character(%s), "encoding"])', varname, varname),

Thanks!