Homework 6

Question 1

coeffs=polyfit (x, y, c)
(c - exponents)

Answer 1

gives you m and b at the c exponent

Question 2

absolute error

Answer 2

abs(y-yfit)
[max_error,max_loc]=max(abs_err)

Question 3

SSE

Answer 3

sum((y-yfit).^2)

Question 4

SST

Answer 4

sum((y-mean(y)).^2)

Question 5

rSquared

Answer 5

1(SSE/SST)

Question 6

polyval(ybestfit,x)

Answer 6

returns the value of ybestfit at x

Question 7

ybestfit(linear) =

Answer 7

coeffs(1)x + coeffs(2)

Question 8

ybestfit(polynomial) =

Answer 8

coeffs=polyfit(x,y,order)
xnew=linspace(min(x),max(x),300)
= polyval (coeffs,xnew)