Calculating value y for each XI and XII in MATLAB:

Question

I am currently working in matlab to design a way to reconstruct 3D data. For this I have two pictures with black points. The difference in the amount of points per frame is key for the reconstruction, but MATLAB gives an error when matrixes are not equal. This is happening becaus the code is not doing what I want it to do, so can anyone hel me with the following?

I have two columns of Xdata: XLI and XRI

What matlab does when I do XLI-XRI is substracting the pairs i.e XLI(1)-XRI(1) etc, but I want to substract each value of XRI of every value of XLI. i.e

XLI(1)-XRI(1,2,3,4 etc)
XLI(2)-XRI(1 2 3 4 etc)

and so on

Can anyone help?

Dennis Jaheruddin · Answer 1 · 2016-02-02T10:55:04.657

2

I think you are looking for a way to deduct all combinations from eachother. Here is an example of how you can do that with bsxfun:

 xLI = [1 2 3]
 xRI = [1 2]
 bsxfun(@minus,xLI ,xRI')

edited Feb 02 '16 at 10:55

answered May 14 '14 at 10:47

Dennis Jaheruddin

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You might want to transpose one of the vectors to ensure this code runs... At least in more recent versions of MATLAB. – rayryeng Jan 31 '16 at 02:25
@rayryeng Not in the opportunity to test, but I will take your word for it. Have updated the answer. – Dennis Jaheruddin Feb 02 '16 at 10:55

score 0 · Answer 2 · answered May 14 '14 at 13:48

I cannot comment on Dennis's post (not enough points on this website) : his solution should work, but depending on your version of Matlab you might get a "Error using ==> bsxfun" and need to transpose either xLI or xRI for that to work :

bsxfun(@minus,xLI' ,xRI)

Best,

Tepp

Calculating value y for each XI and XII in MATLAB:

2 Answers2