how to get probability data (y values) from probplot?

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Hello dear.
I want to manage and work on probability data produced by a probplot function.
I have my dataset (data) which is a vector of something like thermal index.
I apply the probplot Matlab command with an exponentialpr distribution, and I would like to find the intercept points between the exponential function (black dashed line) and my data, in terms of y-values so the probability.
figure,probplot('exponential',data)
untitled.jpg
I know that the equation of the black dashed shold be
y=f(x|mu)=1/mu*exp^(-x/mu)
where mu (μ) is the mean of the function and could be calculted as
pd=fitdist(data,'exponential');
mu=pd.mu;
Now, I have to find a certain threshold for a probability value which corresponds to the first intercept of the black dashed line with my probability exponential distribution, but at the moment I don't know how to act on the Y_data from probplot function.
Any helps?
Thank you!
  3 Comments
fransec
fransec on 4 Jun 2019
I am not able to have access on the properties and object of the graphic array.
Could you explain with a mroe detail, please? Thank you.
fransec
fransec on 4 Jun 2019
I got in the h = probplot('exponential',data) which is a graphic primitive data of matlab
h =
2x1 graphics array:
Line (data)
FunctionLine
and I extracted the value of x and y from probplot, both for my dataset (Line) and for the black line of the function (FunctionLine).
xdata=h(1,1).XData;
ydata=h(1,1).YData;
xfunction=h(2,1).XData;
yfunction=h(2,1).YData;
The problem is that for the y data( ydata and yfunction), the values have completely a different range and they don't go from 0 to 1 as expressed in the probplot graph. It seems that they have been converted to be plotted in the range between 0 and 1 as the probabilty, but really they don't have those values (for example max of ydata is 7.9)...

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