After the varibles as $alldata; I wrote this for call an R script called rCommands

echo "<p><pre>".print_r($allData, true)."</pre></p>";
echo "<p>Saving the received json into file dataReceived/input_".$timeStamp.".json</p>"; 
file_put_contents("dataReceived/input_".$timeStamp.".json", json_encode($allData)); 
echo "<p>Calling R code to compute min, mean, and max values</p>";
exec("Rscript rCommands.txt ".$timeStamp);
echo "<p>Parsing the result dataReceived/output_".$timeStamp.".json of the R code</p>";
$result = json_decode(file_get_contents("dataReceived/output_".$timeStamp.".json"), true);
echo "<p>Result: ".print_r($result, true)."</p>";```

Here the R code in which I want to obtain a data.frame, and then use for the statistical analysis

library("RJSONIO")
args = commandArgs(trailingOnly=TRUE)
if (length(args) != 1) {
  stop("Exactly one argument must be supplied (timestamp).n", call.=FALSE)
}
allData<- fromJSON(paste("dataReceived/input_", args[1], ".json", sep = ""))
data= as.data.frame(allData)
x <- toJSON(data)
fileConn<-file(paste("dataReceived/output_", args[1], ".json", sep = ""))
writeLines(x, fileConn)
close(fileConn)