MATLAB Sum Y Values for Repeating X Values to Plot 0-Crossing Point

[DariusZizys]

Hello guys,

Have an issue here.
I have a large array of numbers, X and Y values.These are coordinates of 9 curves on the same x-axis , so the X values are repeating (433 X values repeating 9 times), what I need to do is to sum Y values for each X value separately. and then plot it (bar plot would be great), I need to see at which place the sum ofY values cross he 0 axis ( the Y values are both possitive an negative).

Thanks in advance!

 

[kreil]

Hi Darius,

Can you show some code that you've written to try to solve this? I think that what you need to use is the accumarray function, which can sum all of the Y values that have the same X value.

http://www.mathworks.com/help/matlab/ref/accumarray.html