Singularities at end point in integration

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SUMMARY

The discussion centers on performing integration with singularities at the endpoints using MATLAB. The user seeks a MATLAB routine equivalent to the Fortran routine "dqawse.f" from quadpack, which handles algebraico-logarithmic end point singularities. The user has explored "gausscc.m" for Chebyshev-Curtis quadrature but found it inadequate for singularities. Suggestions include using WolframAlpha for known parameters or approximating the function near the singularity for analytical integration.

PREREQUISITES
  • Understanding of integration techniques involving singularities
  • Familiarity with MATLAB programming and its numerical methods
  • Knowledge of Chebyshev-Curtis quadrature
  • Basic concepts of Taylor expansion for function approximation
NEXT STEPS
  • Research MATLAB's built-in functions for numerical integration, such as "integral" and "integral2"
  • Explore the implementation of "dqawse.f" in MATLAB for custom integration routines
  • Investigate advanced numerical methods for handling singularities, such as adaptive quadrature
  • Learn about function approximation techniques, specifically Taylor series expansions
USEFUL FOR

Mathematicians, engineers, and researchers involved in numerical analysis, particularly those working with MATLAB and requiring integration techniques for functions with singularities.

ashesh
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singularities at end point in integration...

Hi,

I Need to perform an integration with poles and zeros in the integrand. Please let me know if there a MATLAB routine/program that can handle the definite integral

sqrt((x-a)*(x-b)/((x-c)*(x-d)))

between the limits (c,d), (a,d), (a,b) or (b,c).

I have read about the routine in quadpack called "dqawse.f" which can perform "integration of functions having algebraico-logarithmic end point singularities".

I need a MATLAB equivalent program that can perform this type of integration. I have checked gausscc.m file (http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=2905&objectType=file) which does integration by Chebychev-Curtis quadrature, but that seems to be no good in handling singularities.

Hope someone can give some leads to solve the above problem.

Thanks in advance.
Ashesh
 
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I would use WoframAlpha if the parameters are known. If not, I'm not aware of a general solution to it, except perhaps a Taylor expansion.
 
Here's a simple approach:
Approximate the function by a simpler function at the singularity, which you can integrate analytically.
Integrate the singularity. Then integrate all the rest with your favorite numerical method.
 

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