arduino matlab plotting problem

hi,

I have used my ultrasonic sensor with arduino to display the distance now I want to plot these data in matlab the code I used for arduino is

#define ECHOPIN 3
#define TRIGPIN 2

void setup()
{
Serial.begin(9600);
pinMode(ECHOPIN,INPUT);
pinMode(TRIGPIN,OUTPUT);
}

void loop()
{
  // Start Ranging -Generating a trigger og 10us burst
digitalWrite(TRIGPIN ,LOW);
delayMicroseconds(2);
digitalWrite(TRIGPIN,HIGH);
delayMicroseconds(10);
digitalWrite(TRIGPIN,LOW);

float distance =pulseIn(ECHOPIN,HIGH);
distance=distance/58;
Serial.print(distance);
Serial.print("cm");
delay(200);
  // put your main code here, to run repeatedly:

}

and the code I used for matlab is

close all
clc
arduino=serial('COM3','BaudRate',9600);
fopen(arduino); % initiate arduino communication
CM(1)=0;
time(1)=0;
i=1;
tic;
while (toc<=20)
   CM(2)=fscanf(arduino,'%f');
   time(2)=toc;
   figure(1);
   grid on;
   axis([toc-10, toc+10, 0, 35])
   h(i)=plot(time,CM,'b','LineWidth',4);
   hold on
   CM(1)=CM(2);
   time(1)=time(2);
 if(i >= 300)
   delete(h(i-299));
   end
i=i+1;
end 
fclose(arduino); % end communication with arduino

the problem is that the plot i got is not a real time plot ,it does not display the continous data of the ultrasonic senor

I want to know if my matlab code is correct ?

Im new to matlab and i want a help plz