clear
X1=10+0.5*randn([6,3]); X2=10.8+0.4*randn([6,4]); X3=10+randn([6,3]);
X=[X1,X2,X3];
x=mean(X); R=max(X)-min(X);
D=1; A2=0.483; D3=0; D4=2.004; d2=2.534; Rh=d2*D/3;
m=10; KVx=m, VYx=m+A2*Rh, VAx=m-A2*Rh
KVR=Rh, VYR=D4*Rh, VAR=D3*Rh
k=1:10;
plot(k,VAx*ones([1,10])), grid
figure(4), plot(k,x,'k',k,KVx*ones([1,10]),'k--',k,VYx*ones([1,10]),'k',k,VAx*ones([1,10]),'k')