How to Add Linear Trendline that Considers Errorbars
26 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
x = [662 1173 1332];
y = [654.3724 1124.827 1271.512];
yneg = [0.089207 0.799102 0.799102];
ypos = [0.089207 0.799102 0.799102];
xneg = [0.174485 1.796169 1.672245];
xpos = [0.174485 1.796169 1.672245];
errorbar(x,y,yneg,ypos,xneg,xpos)
Above is my code. I have three data points with errorbars. How can I add a special linear trendline (if there is such option for me) for the three points that takes into account the errorbars? In other words, it will be different from a regular trendline for the points without errorbars.
2 Kommentare
Rik
am 31 Mär. 2017
I think you will either need the original dataset or you need to generate a dataset. But more important is the question what you mean with taking into account the errorbars.
Antworten (3)
Joseph Cheng
am 31 Mär. 2017
Bearbeitet: Joseph Cheng
am 31 Mär. 2017
so if you want to take in the span of the error bars why not take into account the error bar points:
clf;
x = [1 2 3]';
y = [1 2 3]';
yneg = [.25 .1 .01];
ypos = [.15 .05 .01];
errorbar(x,y,yneg,ypos)
Ofitline = polyfit(x,y,1);
hold on, plot(x,polyval(Ofitline,x),'--b')
Errx = repmat(x,3,1);
Erry = [y; y-yneg';y+ypos'];
Efitline = polyfit(Errx,Erry,1);
hold on, plot(x,polyval(Efitline,x),'--r')
i did it in one position as i don't yet have the both direction error bars. but just fit a line with points at the bounds of the error bar. I did not include the original data as it can weight the answer in the positive or error bar.
0 Kommentare
DS
am 1 Okt. 2018
Bearbeitet: DS
am 1 Okt. 2018
The error bars of your dataset represents a distribution of the data. I would suggest use the original data to fit the line. If you generate a set of data using your error bar, make sure that this new set of data represent the correct distribution of the original data. For example, if you just linspace(mean-error, mean+error, 100), these 100 points distribute evenly from mean-error to mean+error. But the thing is that, if your data follow a normal distribution (there are more data points close to the mean value), the evenly distributed data points from linspace() are NOT useful in the fitting.
0 Kommentare
Isabel Allegro
am 17 Mär. 2023
Bearbeitet: Isabel Allegro
am 4 Apr. 2023
You should be able to use this function https://de.mathworks.com/matlabcentral/fileexchange/26586-linear-regression-with-errors-in-x-and-y
0 Kommentare
Siehe auch
Kategorien
Mehr zu Errorbars finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!