Interpolation in negative axis?

I have fitted my data with a gaussion function. the curve is basically lying in first coordinate and not starting from zero. I want to calculate the value of x for y=0 (x would then definitely come in 2nd coordinate). How to find this value of x. In figure, the first fitted curve (not starting from zero)

fun1 = @(p,xdata) p(1).*(1-exp(-xdata./p(2)))+5000;

I want to a value of x for y=0 (when curve touches x axis). How to find it. Any lead will be appricated.

Answer 1

[Star Strider]

Once you have your fitted ‘p’ values, you can find the x value at y=0 with the fzero function.

Try this:

fun1 = @(p,xdata) p(1).*(1-exp(-xdata./p(2)))+5000;

x_intercept = fzero(@(xdata) fun1(p,xdata), -1);

[Raju]

Thank you so much for your answer. It's working.

[Star Strider]

As always, my pleasure.

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