Matlab reading from serial port at specific sampli

I am trying to read values from two sensors (on my arduino) that are being sent to the serial port, with the matlab code below. However, it errors saying ??? Attempted to access sensor1(1); index out of bounds because numel(sensor1)=0 and if the error does not occur the results are not accurate. I know this because I simply sent 1 and 2 as the sensor values to the com port and the resulting two arrays contained some zeros too (when one should be all 1's and the other all 2's). Thanks any help will be greatly appreciated.

Here is my matlab code:

close all;
clc;

fs = 1000;  % sampling frequency (samplings per second)
mt = 20;  % time for measurements

ind = 1;
nind = 1;

%Open serial port
delete(instrfind({'Port'},{'/dev/tty.usbmodem641'}));
serial_port=serial('/dev/tty.usbmodem641');
serial_port.BaudRate=115200;
warning('off','MATLAB:serial:fscanf:unsuccessfulRead');

%Open serial port
fopen(serial_port); 

pause(2);

%Declare sample count
sample_count=1;


tic;
while toc < mt

    time(ind) = toc;

    sensor1=fscanf(serial_port,'%d')';
    sensor2=fscanf(serial_port,'%d')';

    channel1(ind) = (sensor1(1));
    channel2(ind) = (sensor2(1));

    % wait for appropriate time for next measurement
    while( nind == ind )
        nind = floor(toc*fs) + 1;
    end
    ind = nind;


end 

%close connection
 fclose(serial_port); 
 delete(serial_port);

this is my sending arduino code:

int sensor1=0;
int sensor2= 0;

void setup(){

  Serial.begin(115200);

}

void loop(){

  sensor1= 1;
  sensor2= 2;

  Serial.println(sensor1);
  Serial.println(sensor2);


}

You could try using this before your fscanf statements:

while(get(serial_port,'BytesToRead')<2) ; end

This will wait until there are two bytes in the serial buffer before you read them.

PS: If you are sending numbers you would be better off sending them as numbers rather than as a string - you will need to send three bytes to represent 101 - one for each digit - while this can be sent as a single byte. Use fwrite and fread to do this in Matlab, Serial.write and Serial.read on Arduino.