I have no idea what the author is trying to do or why.
Why do you want to do a linear regression on random segments?
Author talks about reasoning, but I think it would make the point clearer if there was a section that reasoned about the result on FTE.
Why are there a white upward segment and a white downward segment? Inside the blue segment there is a clear downward segment, about the size of the red downward segment. Why did it not get its own color?
>Why do you want to do a linear regression on random segments?
It may be worth reading the article fully -- why random segments and the logic of it is explained fairly well I think.
>Author talks about reasoning, but I think it would make the point clearer if there was a section that reasoned about the result on FTE.
Same as above. Have a read of the comments around the implementation.
>Why are there a white upward segment and a white downward segment?
There are no white segments -- those are gaps.
> Inside the blue segment there is a clear downward segment, about the size of the red downward segment.
I guess you mean the last graph? I think if the isotonic regression was plotted on the graphs, it'd be clearer why that segmentation makes sense. But in brief it is about how well an isotonic regression fits in the segments as opposed to how it may visually seem -- the two can come apart.
Why do you want to do a linear regression on random segments?
Author talks about reasoning, but I think it would make the point clearer if there was a section that reasoned about the result on FTE.
Why are there a white upward segment and a white downward segment? Inside the blue segment there is a clear downward segment, about the size of the red downward segment. Why did it not get its own color?