Compare 2 or more lines
Do they have the same
intercept (one line) or different intercepts (different
parallel lines)?
Parametric Approach: Analysis of
Covariance. See chapter 11.
Nonparametric Approach. A rank-sum test on
residuals from a Theil-Sen line of Y vs. X. See chapter 12.
Do the lines
have the same slope? (Are they parallel?)
Parametric Approach: Analysis of
Covariance. See chapter 11
Nonparametric Approach. Do confidence
intervals on the Sen slope overlap? See chapter 10.
Chapter references are to the course textbook Statistical Methods in Water
Resources.