save data and use it back in the loop with condition

a=abs(randn(1,100));

for n=1:10

count=0;
for angle=0:360
   count=count+1;

Xd=(D*cos(angle*pi/180));
Yd=(D*sin(angle*pi/180));
d1(n,count)= sqrt((Yd-y(n))^2+(Xd-x(n))^2);%distance between destination and sensor for 0 to 360 degree.
k(n,count)=((2*pi)/lambda)*(d1(n,count)); %phase lag for each sensor.
yy(n,count)=(exp(-i*k(n,count))*c(n)*a(n)); %weight multiplication to correct the phase lag.

end
end

Y=sum(yy);
YY=abs(Y);
p=20*log10(YY/max(YY));%normalized power in dB;

in the code above, i am creating an array (a) with random values. then i use the array of data to calculate (yy). i test the (yy) value, if the value of (yy) is better than the previous (yy) value, i will use the current (a) array of data to calculate the (yy) value for the next loop. If not i will use the previous (a) value to calculate the next (yy) value. Now the question is, how can I save the (a) value to use it back for the calculation for the next loop. i mean, how can I use the previous (a) value to calculate the (yy) value for the next loop? And, how can I replace the saved (a) value with another new array of (a) values?