Questions tagged [numerics]
Questions on the numerical functions of Mathematica, implementing numerical methods and numerical computing with Mathematica.
2,278 questions
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Using a Solution of NSolve in Further Calculations [closed]
I want to take the solution from an NSolve and perform operations on the result, a bit like the following code. Please can someone advise on how I 'extract' the NSolve solution as a variable. Thanks
<...
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What could I do when NSolve fails to give solution?
My code was:
f[x_]:=(Exp[x]-2)/x;
NSolve[{f[a]==f[b],f'[a]==f'[b],a>b},{a,b},Reals]
The output was an empty list {}. However,...
- 315
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Strange results about the sine function of a big integer
I want to calculate the sine of a big integer, e.g., Sin[10^50], but found that N[Sin[10^50]], N[Sin[10^50],10], and N[Sin[10^50],20] give different results:
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Issue with higher order derivatives of list data
I have tried to plot some experimental data (https://drive.google.com/file/d/1ouJWkQ1CQA6Z3fFlMqDb1JPF4wg16Efr/view?usp=drive_link). However, when I calculate the second derivative, sharp peaks appear ...
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How to make sure whether the vertical line in the given plot are artifacts or real solutions?
I have the Root[...] function in terms of a real positive $x$ variable, for which the code is given below.
I plotted this function for $0<x<300$, and I get ...
- 63
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Difficulty Solving a PDE System with Initial and Boundary Conditions in Mathematica
I am trying to solve the following system of nonlinear PDEs in Mathematica, but I'm encountering difficulties, particularly with defining the initial conditions. Here's the system I am working with:
$$...
- 334
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FindRoot error: FindRoot::sszero, FindRoot::dfmin, FindRoot::lstol
I'm trying to solve a highly non-linear system using FindRoot. I need to find r for fixed a=0.9; k=1; m=1; M=1; but at for ...
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Avoiding overflow when computing tetration
Is there any method by which I can avoid overflow in the following code?
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- 129
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How to numerically check the binoharmonic series?
$$
\sum _{k=1}^{\infty }\frac{4^kH_{2k}^2}{k^2\binom{2k}{k}}=8G^2+\frac{103}{2}\zeta \left(4\right)-22\operatorname{Li}_4\left(\frac{1}{2}\right)+7\ln ^2\left(2\right)\zeta \left(2\right)-\frac{11}{12}...
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Incompatible change in numerics in V14.2 in Table[], Range[]
There's a change in the outputs of Table[] and Range[] in V14.2 (compared to V14.1) on MacOS ARM when iterating through machine ...
- 252k
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Minimization of a numerical model function
I have a simple model coded as a function mod[x], which returns a single value. Inside of the model I solve a.o. a small system of linear differential equations, with x being one of the coefficents. ...
- 1,294
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How to eliminate or reduce the error of the integration?
As can be seen in the following code, jr is a numerical integration of x and y. Here, in ...
- 35
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How to simplify such that the imaginary part is removed
I'm trying to solve an equation for \Omega and non-zero S.
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- 129
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Solving a system of 4 equations gives wrong answer but no errors
I'm trying to solve a system of 4 equations for r, Ω, W, and ...
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how to debug findmaximum
I have the following code which is self contained. It is doing multivariable numeric optimisation with a user supplied gradient. The first call to FindMaximum ...
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