rem Geometric Regression
cls
print
print "Geometric Regression"
print

j=0
k=0
l=0
m=0
r2=0

rem data entry
input "number of known points? ";n
for i=1 to n
 print
 print "x(";i;")= ";
 input " ";x
 print "y(";i;")= ";
 input " ";y

 y=log(y)
 x=log(x)
 j=j+x
 k=k+y
 l=l+x^2
 m=m+y^2
 r2=r2+x*y
next i

b=(n*r2-k*j)/(n*l-j^2)
a=(k-b*j)/n
print
print "f(x)=";exp(a);"*x^";b
print
j=b*(r2-j*k/n)
m=m-k^2/n
k=m-j
r2=j/m
print "Coeff. of Determination (r^2) = ";r2
print "Coeff. of Correlation (r2)^.5 = ";r2^.5
print "Standard error (k/(n-2))^.5 = ";(k/(n-2))^.5
print

rem "estimate y coordinate"
[again]
print
print "Interpolation (enter x=q to end program) ";
input "x= ";x$
if x$="q" then
 end
end if
x=val(x$)
print "y= ";exp(a)*x^b
goto [again]