How can i set the sampling rate for Arduino analogRead in matlab code?

I want to use current sensor ACS712 to read the real time value for of 50Hz line current with the following code I found on the internet, but it not given the real-time signal. How can I set the sampling rate?

if true
  % code
end
a = arduino(); % Create a figure window to monitor the live data
tmax = 10; % Total time for data collection in seconds
figure(1),
grid on,
xlabel ('Time (s)'), ylabel('Voltage');
axis([0 tmax -2.5 2.5]); % set initial index value, starting value
k = 0;  %index
v = 0;  %voltage
t = 0;  %time
tic % Start timer
while toc <= tmax
  k = k + 1;
  v(k) = readVoltage(a,'A0')-1.47; %maximum value=3.935
  t(k) = toc;
      % Now plot the data
  if k > 1
      line([t(k-1) t(k)],[v(k-1) v(k)]);
      drawnow;
  end
end

Answer 1

[Sadam Hussain]

Hello, friend, I have the same problem I can not get accurate data did you get correct once