founding and extracting critical point of increasing graph.

Hey, I have 2 vectors, one for voltage called V and one for the current called I,

the voltage I recieving from the graph is need theoraticlly be on the zero till the critic point when it start increasing, but in fact the voltage is near zero doing small flactuations so using find() function would not help this time to extract the critic point of increasing from zero

for example:

in this graph we see that the critic point is somwhere around I_c ~~ 2 A

but i want some script code that can help me extract the most close value of the critical current, with a good criterion

thanks.

[Alex Mcaulley]

Probably you need a combination of smooth function and diff function

[Shayan Sepahvand]

Cause your graph look likes a 2nd order polynomial, i think smooth(y,'lowess') and next trying to find the crossing point with a significantly small point (e.g. 1e-4) will solve the problem.