How can plot the residuals as vertical distances from the data point to the fitted curve

How to plot the results like the 1st image ?

Answer 1

[dpb]

If your data are x,y and yh the predicted values, then

scatter(x,y)   % the data circles
hold on
plot(x,yh,':')  % the regression line
arrayfun(@(x,y,yh) line([x x],[y yh],'linestyle','-'),x,y,yh)  % the stem lines

NB: the x,y,yh in the @(x,y,yh) portion of the anonymous function are dummy arguments substituted into the function definition by reference; the actual data are the three arrays as given as the arguments to arrayfun.

doc arrayfun  % for more details and anonymous functions.

Takes same number of plotting commands as S-Strider's solution but dispenses with the duplicated data for the lines data array at the expense of a little complexity in arrayfun

[dpb]

Seems like a good request for enhancement to stem, though...I couldn't figure out any way to fool it and its source code is quite complex enough didn't care to try to mung on it for just this ???

Answer 2

[Jack]

Thank your all guys, either way is to construct those lines and plot them separately, I thought there are build-in function.

[dpb]

For many things there are but not this particular one. stem only works from the baseline; won't take an arbitrary reference. Which is why I suggested file an enhancement request.