How can I easily compute the integral of a hypergeometric function?

In summary, The conversation discusses the use of special functions, specifically the Gaussian Hypergeometric function and incomplete Beta function, in solving an indefinite integral with constant values. It is noted that the integral cannot be expressed with a finite number of elementary functions and must be solved using numerical methods. The conversation also mentions different software options, such as Mathematica and WolframAlpha, that can be used to calculate the area under the curve.
  • #1
giuseppesk82
3
0
I am trying to solve the integral of the following equation:

y= a + (b/(1+(x/c)^d)

with a,b,c,d as constant

I will apprecciate your help

Thanks
 
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  • #2
This indefinite integral cannot be expressed with a combination of a finite number of elementary functions. It requires special functions, namely the Gaussian Hypergeometric function (2F1), or another special function of lower level namely the incomplete Beta function (but in complex domain).
 

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  • #3
JJacquelin said:
This indefinite integral cannot be expressed with a combination of a finite number of elementary functions. It requires special functions, namely the Gaussian Hypergeometric function (2F1), or another special function of lower level namely the incomplete Beta function (but in complex domain).

Thank you Jacqueline,
I am trying to calculate the area under the curve but I do not know how to arrange the Gaussian Hypergeometric function or the Beta function.

Can you help me, please? Can you explain the procedure to reach my goal?

For example:
a= 2,43; b= 6; c= 2.5; δ= 9.68 with interval: x1=2.5 and x2=7.5

it is not a question of result, but I would like to understand the porcedure.

Thank you in advance
 
  • #4
It is possible to compute the numerical value of an hypergeometric function "by hand", thanks to series expansion. But it would be awfully boring and time consuming. That was the way to do it in the good old days, before the age of computers.
If you have "Mathematica" or any other math. package, certainly, the hypergeometric function is included, allowing to compute numerical values.
But the most simple way is to use a numerical integrator. Even some pocket calculator can do that. Just program the function to integrate (no need for hypergeometric function). Also more advanced softwares are very simple to use, for example MatCad (screen copy below)
Some calculators are on free access on the web., for example WolframAlpha (screen copy below), use Google to find them.
 

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  • #5
JJacquelin said:
It is possible to compute the numerical value of an hypergeometric function "by hand", thanks to series expansion. But it would be awfully boring and time consuming. That was the way to do it in the good old days, before the age of computers.
If you have "Mathematica" or any other math. package, certainly, the hypergeometric function is included, allowing to compute numerical values.
But the most simple way is to use a numerical integrator. Even some pocket calculator can do that. Just program the function to integrate (no need for hypergeometric function). Also more advanced softwares are very simple to use, for example MatCad (screen copy below)
Some calculators are on free access on the web., for example WolframAlpha (screen copy below), use Google to find them.

Thank you Jacquelin!
You solved my doubts, I will use WolframAlpha to calculate the area.
 

1. What is a logistic curve integral?

A logistic curve integral is a mathematical calculation that represents the area under a logistic curve, which is a sigmoidal (S-shaped) curve commonly used to model population growth or saturation in various fields such as biology and economics.

2. How is a logistic curve integral calculated?

A logistic curve integral is typically calculated using calculus, specifically by taking the definite integral of the logistic function over a given range of values. This can be done using numerical methods or by hand using integration techniques.

3. What is the purpose of a logistic curve integral?

The purpose of a logistic curve integral is to quantify the amount of growth or saturation that occurs within a specific range of values. This can be useful in predicting future trends or analyzing past data in fields such as population dynamics and market trends.

4. Are there any real-world applications of logistic curve integrals?

Yes, logistic curve integrals have many real-world applications. They are commonly used in fields such as biology to model population growth and in economics to analyze market trends. They are also used in statistics and data analysis to fit curves to data sets.

5. What are some limitations of logistic curve integrals?

One limitation of logistic curve integrals is that they assume a constant growth rate, which may not always be the case in real-world situations. They also rely on the accuracy of the data and the assumptions made in the model. Additionally, logistic curve integrals may not be appropriate for all types of data and may require additional statistical analysis to be fully useful.

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