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

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fransec 2019-6-4

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评论： fransec 2019-6-4

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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)

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!

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fransec 2019-6-4

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 2019-6-4

在 MATLAB Online 中打开

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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