I implemented first order deming regression on an array of x
and y
values. I tried to calculate the confidence interval, which in my understanding should be two values (upper and lower) for slope and two values for intercept. When I plot these two values they should be two straight lines too
However, I have seen in few analyses showing confidence for linear regression as a curve? (example in picture below) .
I do not understand where this comes from, what does this represents and how to implement in in a first order regression. So if anyone can guide me a place to start to understand about this would be a great help.