function  gmcal=huise(x)
sizexd2 = size(x,2);
k=0;
for y1=x
    k=k+1;
    if k>1
        x1(k)=x1(k-1)+x(k);
        z1(k-1)=-0.5*(x1(k)+x1(k-1));   
        yn1(k-1)=x(k);
    else
        x1(k)=x(k);
    end
end
sizez1=size(z1,2);
z2 = z1';
z3 = ones(1,sizez1)';
YN = yn1';   
B=[z2 z3];
au0=inv(B'*B)*B'*YN;
au = au0';
afor = au(1);
ufor = au(2);
ua = au(2)./au(1);
constant1 = x(1)-ua;
afor1 = -afor;
x1t1 = 'x1(t+1)';
estr = 'exp';
tstr = 't';
leftbra = '(';
rightbra = ')';
strcat(x1t1,'=',num2str(constant1),estr,leftbra,num2str(afor1),tstr,rightbra,'+',leftbra,num2str(ua),rightbra)
k2 = 0;
for y2 = x1
    k2 = k2 + 1;
    if k2 > k  
    else
        ze1(k2) = exp(-(k2-1)*afor);  
    end
end
sizeze1 = size(ze1,2);
z4 = ones(1,sizeze1)';
G=[ze1' z4];
X1 = x1';
au20=inv(G'*G)*G'*X1;
au2 = au20';
Aval = au2(1);
Bval = au2(2);
strcat(x1t1,'=',num2str(Aval),estr,leftbra,num2str(afor1),tstr,rightbra,'+',leftbra,num2str(Bval),rightbra)
nfinal = sizexd2-1 + 1;
for  k3=1:nfinal
    x3fcast(k3) = constant1*exp(afor1*k3)+ua;
end
for  k31=nfinal:-1:0
    if k31>1
        x31fcast(k31+1) = x3fcast(k31)-x3fcast(k31-1);
    else
        if k31>0
            x31fcast(k31+1) = x3fcast(k31)-x(1);
        else
            x31fcast(k31+1) = x(1);
        end
    end 
end
x31fcast
for  k4=1:nfinal
    x4fcast(k4) = Aval*exp(afor1*k4)+Bval;
end
for  k41=nfinal:-1:0
    if k41>1
        x41fcast(k41+1) = x4fcast(k41)-x4fcast(k41-1);
    else
        if k41>0
            x41fcast(k41+1) = x4fcast(k41)-x(1);
        else
            x41fcast(k41+1) = x(1);
        end
    end
   
end
x41fcast,x
k5 = 0;
for y5 = x
    k5 = k5 + 1;
    if k5 > sizexd2  
    else
        err1(k5) = x(k5) - x41fcast(k5);  
    end
end
xavg = mean(x);
err1avg = mean(err1);
k5 = 0;
s1total = 0 ;
for y5 = x
    k5 = k5 + 1;
    if k5 > sizexd2  
    else
        s1total = s1total + (x(k5) - xavg)^2;  
    end
end
s1suqare = s1total ./ sizexd2;
s1sqrt = sqrt(s1suqare);
k5 = 0;
s2total = 0 ;
for y5 = x
    k5 = k5 + 1;
    if k5 > sizexd2  
    else
        s2total = s2total + (err1(k5) - err1avg)^2;  
    end
end
s2suqare = s2total ./ sizexd2;

Cval = sqrt(s2suqare ./ s1suqare);
Cval
k5 = 0;
pnum = 0 ;
for y5 = x
    k5 = k5 + 1;
    if abs( err1(k5) - err1avg ) < 0.6745 * s1sqrt
        pnum = pnum + 1;
   
    else
    end
end
pval = pnum ./ sizexd2;
pval