New data frame after function is empty - r

Question

I prepare a function to have a temporary dataframe, but whent i apply this function on my old dataframe , the temporary dataframe is empty. How can i solve this ?
I tried this code :
data_a <- as.data.frame(cbind(pop=c("a1","b2","c3","d4","d5"),
PA1=c(1,40,430,4330,43330),
PA2=c(2,50,530,5330,53330)))
perm_all <- function(dat,vname,loc1, loc2){
popu <- dat["vname"]
locci_1 <- sample(dat["loc1"], replace = F)
locci_2 <- sample(dat["loc2"], replace = F)
data_a_1 <- as.data.frame(cbind(popu, locci_1, locci_2))
return(data_a_1)
}
data_3 <- perm_all(dat= "data_a",vname="pop",loc1="PA1",loc2="PA2")
I've tried to convert the data_a with
data_a <- as.matrix(data_a)
and
popu <- sample(dat[,1], replace = F)
but they didn't work too
Thank's :)

Answer 1

There are maybe multiple issues. First, when you have created your data frame, be aware that data.frame function family treat string as a factor by default. It may be not what you want.
Then #NURAIMIAZIMAH is right, your function needs a data frame to work properly, so :
data_3 <- perm_all(dat= data_a,vname="pop",loc1="PA1",loc2="PA2")
is a good start.
Moreover, you give value to vector like vname, loc1 and loc2. But you only use the name of these objects in your function, because you forgot to remove quotation mark.
perm_all <- function(dat,vname,loc1, loc2){
popu <- dat[vname]
locci_1 <- sample(dat[loc1], replace = F)
locci_2 <- sample(dat[loc2], replace = F)
data_a_1 <- as.data.frame(cbind(popu, locci_1, locci_2))
return(data_a_1)
}
Now your function should work, but maybe not in the way you would like to. Because there won't be any permutations in your data_3 table. If you look carefully, the type of return of this part of the code dat[loc1] is a data frame. You certainly want a vector to permute your data, so you have to subset your data frame like this : dat[,loc1].
This code below should do what you expect.
data_a <- as.data.frame(cbind(pop=c("a1","b2","c3","d4","d5"),
PA1=c(1,40,430,4330,43330),
PA2=c(2,50,530,5330,53330)))
perm_all <- function(dat,vname,loc1, loc2){
popu <- dat[vname]
locci_1 <- sample(dat[,loc1], replace = F)
locci_2 <- sample(dat[,loc2], replace = F)
data_a_1 <- as.data.frame(cbind(popu, locci_1, locci_2))
return(data_a_1)
}
data_3 <- perm_all(dat= data_a,vname="pop",loc1="PA1",loc2="PA2")
See you.