void grafic(String myDato, int x, int y){
  fill(0);
  line(x,y,x,y-200);
  line(x,y,x+400,y);
 
  float[] dato=float(split(myDato,':');

  for(int i=1;i<=a;i++) {
    line(x,y-map(dato[i-1],0,1,0,200),x+4,y-map(dato[i],0,1,0,200));
  }
}

this is a part of a program i made to draw with processing a grafic of distance acquired with the ARDUINO board.

to send the data to the function grafic i need to join the array in the main with the function join and then i have to split it in the function but in the 5th line processing found an error:
expecting DOT found 'dato'

can someone help me?