Write all variable values to a table - r

Question

I'm a total R-newbie and I have a simple question which might be hilarious but I could not find a answer even though I searched for 4 hours. I might miss the concept.
I write a Monte-Carlo script with a lot of variables stored in differnet environments. At the end of every iteration I want to write all variables (the ones which are listed when typing ls()) to a table.
This would be a working example (without the item I ask for) of what I want to do. (Thank you for your help sofar, it helped me to build that example!)
#input data (data will be manipulated for mc later on)
ha<-5
w_eff<-1.9
v_T1<-8
n<-1000 #number of iterations
#function
T1_func <- function(ha_mc, w_eff_mc, v_T1_mc){
T1_result <- ((ha*10)/(w_eff*v_T1));
return(T1_result)
}
for(i in 1:n){ #number of iterations
#MC maipulation (illustrative)
ha_mc<-rnorm(1, ha, sd=1)
w_eff_mc<-rnorm(1, w_eff, sd=1)
v_T1_mc<-rnorm(1, v_T1, sd=1)
#calculation
T1_mc<-T1_func(ha_mc, w_eff_mc, v_T1_mc)
#now I want to write all variables to a table
df<-data.frame(ha, w_eff, v_T1, ha_mc, w_eff_mc, v_T1_mc, T1_mc)
write.table(df, file = "result.txt", append = TRUE, quote = TRUE, sep = " ",
eol = "\n", na = "NA", dec = ".", row.names = FALSE,
col.names = !file.exists("result.txt"), qmethod = c("escape", "double"))
}
My question would be: how do I get that:
df<-data.frame(ha, w_eff, v_T1, ha_mc, w_eff_mc, v_T1_mc, T1_mc)
without writing down all the variables (ha, w_eff, v_T1, ha_mc, w_eff_mc, v_T1_mc, T1_mc) but with something like "ls()". And how do I get that for the variables in the different environments so that I will have a column named "my.env$w_eff".
Thank you very much!

Answer 1

I woud suggest not using ls() and instead making a data.frame which contains the variables you want to store. Here I firstly create the file "results.txt" with the correct column headers (I'm storing values of a, b, and c) and then in each iteration I append the corresponding values to the file. Hope this helps:
n <- 10L
write.table(data.frame("a", "b", "c"), file = "result.txt",
col.names = FALSE, row.names = FALSE)
for (i in seq_len(n)) {
#do MC
a <- rnorm(1L)
b <- exp(a)
c <- a + b
write.table(data.frame(a, b, c), file = "result.txt",
append = TRUE, row.names = i, col.names = FALSE)
}

Answer 2

Thats the solution I found with your help, thx!
write_table_func <- function(env_name, file_part_name, dir_name){
#write input to table
df_input<-data.frame(as.list(get(env_name), all.names=TRUE))
sort.df_input <- df_input[,order(names(df_input))]
filename<-(paste(sep="", dir_name, "/", "tabl_", process_n, "_", process_step_n, file_part_name, ".txt"));
suppressWarnings(write.table(sort.df_input, file = paste(filename), append = TRUE, quote = TRUE, sep = " ",
eol = "\n", na = "NA", dec = ".", row.names = FALSE,
col.names = !file.exists(paste(filename)), qmethod = c("escape", "double")));
rm(df_input);
rm(sort.df_input);
}