Arduino OLED Voltmeter

//Arduino OLED Voltmeter
#include <Wire.h>
#include "U8glib.h"
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE|U8G_I2C_OPT_DEV_0);

int analogInput = 0;
float vout = 0.0;
float vin = 0.0;
float R1 = 100000.0;
float R2 = 10000.0;
int value = 0;
void draw(void)
{
  u8g.setFont(u8g_font_profont17r);
  u8g.drawStr(18, 12, "VOLTAGE");
  u8g.setPrintPos(33,40);
  u8g.drawRFrame(15, 20, 100, 30, 10);
  u8g.println(vin);
  u8g.println("V");
}
void setup(){
   pinMode(analogInput, INPUT);
}
void loop(){
   value = analogRead(analogInput);
   vout = (value * 5.0) / 1024.0;
   vin = vout / (R2/(R1+R2));
   if (vin<0.09) {
   vin=0.0;
}
  u8g.firstPage();
  do
    {
     draw();
    }
  while( u8g.nextPage() );
delay(500);
}