I wrote this code to process data from a serial port. It could run normally for the first iteration, but after that an error shows "NullPointerException". I searched and found this is sometimes associated with problems in initialization. But I still can't fix this... I have just started to learn coding.

 I would appreciate it if anyone could help me out here. Thank you for your time!

here is the code:

import processing.serial.*;

String rawData =null ;

String[] data = null;

float[] num = null;

Serial myport;

void setup(){

myport = new Serial(this,Serial.list()[0],9600);

}

void draw(){

if(myport.available()>0){

  rawData = myport.readStringUntil(' ');

  data =  split(rawData,',');

  num = float(data);       // this is where the error highlights

  println(num);  

}

}