Hello there,

I'm quite new to Matlab and stuck at a problem for a while and thus this is my first question.

What I have: A (x/y) dataset which is depicted by the blue line in the figure below

What I want:

- Two extrapolating lines (depicted by dotted lines) through the maximum slope of the peak and the "ground" line respectively
- Intersection Point of these lines to retrieve its x-coordinate

What I have tried: I tried using the following line for a first try, just to see what happens, however I am unable to plot the extrapolated line (Error Msg. Vectors must be the same length)

`y1=interp1(t,hf,[2500:2600],'linear','extrap')plot(t,y1)`

As said I have not that much experience yet so I would highly appreciate any helpful input for solving this particular problem.

Best regards

## Best Answer