as.numeric is not working

Question

I am developing code with R and trying to integrate it with PHP. In this code after the as.numeric, values will be output as NA on logs.txt and this N = '"15","20","30","40","50"'; (coming from PHP)

# my_rscript.R

args <- commandArgs(TRUE)
N <- args[1]

N=c(N)

cat(N,file="c:/rlogs.txt",append=TRUE)

N=as.numeric(as.character(N))

cat(N,file="c:/rlogs.txt",append=TRUE)

png(filename="temp.png", width=500, height=500)
hist(N, col="lightblue")
dev.off()

I really appreciate your help on this.

Answer 1

Without more detail, you first need to convert the input from a single string to a vector.

That is, you need to strsplit, and in this case gsub to get rid of the extra quotation marks:

N <- '"15","20","30","40","50"'

as.numeric(N)
# [1] NA
# Warning message:
# NAs introduced by coercion 

N <- strsplit(N, ',')[[1]]
N
# [1] "\"15\"" "\"20\"" "\"30\"" "\"40\"" "\"50\""

N <- gsub('"', '', N)
N
# [1] "15" "20" "30" "40" "50"

N <- as.numeric(N)
N
# [1] 15 20 30 40 50