Attempt to set "sep" / "dec" ignored: Error in write.csv format - R

Question

There are similar posts, but none of them actually explained what is this error cause by?

I would like to obtain input in this .csv format: separator ";" and decimal "."

Parameter;Intensitaet;Wert
se;1;0.027
se;1;0.024
se;1;0.021
se;1;0.018
se;1;0.015
se;1;0.012

What I get is:

Parameter;Intensitaet;Wert
se;2;0,0572
se;2;0,2
se;2;0,1
se;2;0,4
se;2;0,0795

The have tried various versions of this code:

> write.csv(final, "SEmurgang.csv", row.names = F, quote = F, sep = ";")
Warning message:
In write.csv(final, "SEmurgang.csv", row.names = F, quote = F, sep = ";") :
  Versuch ignoriert 'sep' zu setzen

> write.csv2(final, "SEmurgang.csv", row.names = F, quote = F, dec=".")
Warning message:
In write.csv2(final, "SEmurgang.csv", row.names = F, quote = F,  :
  Versuch ignoriert 'dec' zu setzen

However, I always get the same error. How can I fix it?

Answer 1

Decimal and separator are hard coded in write.csv2.

write.csv2 uses a comma for the decimal point and a semicolon for the separator, the Excel convention for CSV files in some Western European locales.

If they do not suit you, you are better of using write.table.

write.table is the basic method and write.csv and kin are just a handy wrappers.

Using write.table works for me.

 xy <- data.frame(Parameter = rep("se", 5),
                 Intensitaet = rep(1, 5),
                 Wert = rnorm(5))
 xy
  Parameter Intensitaet         Wert
1        se           1 -1.014570811
2        se           1 -0.680449323
3        se           1 -0.223736133
4        se           1  0.004270224
5        se           1  0.607427274

 write.table(xy, file = "test.txt", row.names = FALSE, dec = ".", sep = ";", 
              quote = FALSE)
 
system("cat test.txt")
Parameter;Intensitaet;Wert
se;1;-1.01457081089331
se;1;-0.68044932280397
se;1;-0.223736133320336
se;1;0.0042702235293986
se;1;0.607427274081342