saving data of loop iteration

Hi every one

I have read data from arduino to matlab through serial port. I nead the data to sent from sensor to matlab at every half second but I want the data to be saved each iteration of the for loop. here is the code I have used

% clear all
instrreset
clc
n=1000;
arduino=serial('COM6','BaudRate',250000);
fopen(arduino);tic
for j=1:4
 for i=1:n  
 d =fscanf(arduino,'%c');
     IncomingString = char(d);
     IncomingString = regexp(IncomingString, '\s*', 'split');
     mic1(i,1)= str2double(IncomingString(1,1));
     mic2(i,1)=str2double(IncomingString(1,2)); 
     mic3(i,1)=str2double (IncomingString(1,3)); 
     mic4(i,1)=str2double (IncomingString(1,4));
     mic5(i,1)= str2double(IncomingString(1,5));
     mic6(i,1)=str2double(IncomingString(1,6));     
 end
 data=[mic1 mic2 mic3 mic4 mic5 mic6];
data(isnan(data))=500;data(data > 700) = 500;toc
plot(data)
end