Questions tagged [numerical-integration]
Questions on the use of numerical functions NIntegrate and NDSolve.
3,648 questions
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Integration by the trapezoid method of an integral with coinciding limits
Please tell me what needs to be changed in my code so that manual numerical integration works the same way as the built-in integration function?
Code with built-in numerical integration:
https://www....
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NDSolve of a beautiful Integro-differential equation
I have a problem when I want to solve this integro-differential equation where the $\chi' (U)$ appears in the integrand. If statement gives the $chiIntegral=0$ for $umax=20$ since the upper bound of ...
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The connection between the number of terms N of the Fourier series and the NIntegrate parameter [closed]
Please tell me, ideas what dependencies of N on any parameter of NIntegrate can be made? N is the number of terms of the Fourier series from which the integral is taken. I tried to connect N with ...
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A function specified as an integral with a variable upper limit [closed]
I create a new function in the form of an integral with a variable upper limit. I add it to the array of functions. I make an animation - I output the obtained functions in order. Please explain what ...
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Integrate and Plot
I have a function which I want to integrate and then plot. The function is a complicated one and getting an error SystemException["MemoryAllocationFailure"]. Can any one fix this? The code ...
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Speed up a Table involving Integrate, then ListDensityPlot
Actually I don't know what is the problem, but the program doesn't give me a result. The last time I ran the program, it has been counting for 5 hours. Maybe I should give the program more time to end....
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Nested NIntegrate Iterations
I'm working on finding the limit of a function that involves nested integration.
I've written the code, and it's running an iterative procedure.
However, each iteration currently takes about 24 hours ...
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How to monitor intermediate values of `NIntegrate`?
I know several examples Monitor, EvaluationMonitor and IntegrationMonitor but cannot ...
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How to avoid singularity during integration? [closed]
I applied the recommendations from my previous question, the calculation time was reduced. Thank you very much!
Now I have a question regarding the calculation of some matrix elements, for example <...
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Plottting a Table of InterpolatingFunction's over distinct ranges
I have a Table of interpolated functions that are generated as parametric solutions via NDSolve. I want to plot all of them, but ...
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Possible ways to increase the speed of integral calculations
The code below is used to calculate the matrix elements He. However, the calculation of each element takes a very long time.
Question: How can the speed of these ...
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How can I be sure NIntegrate does not jump across a branch cut in this case?
I'm working with numerical integrations of multi-valued functions which have integration limits at a branch cut and I don't want the integration "jumping" the branch cut into the next branch ...
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Solution to a two-dimensional integration equation
I was hoping to solve a two dimensional integration equation, which is actually a simplified Schrodinger equation in momentum space:
$$ (x^2-3)f(x,y)-\int_0^\infty du\int_0^{\pi}dv\frac{u^2\sin{v}f(...
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Possible error in gaussian quadrature formula for tetrahedron
Bug introduced in 14.2 or earlier and persisting through 14.2.1.
Mathematica is able to give the 15 gaussian integration points and weights for a Tetrahedron[]
<...
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Looking for Gaussian quadrature rules for triangle and tetrahedron
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The gaussian quadrature rules are very helpful in solving many numerical problems.
Unfortunately Mathematica only provides the one dimensional rules in the package ...
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