# Questions tagged [numerics]

Questions on the numerical functions of Mathematica, implementing numerical methods and numerical computing with Mathematica.

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### NSolve can't solve a system of 2 equations with 2 unknowns

I've been trying to solve a system of 2 equations with 2 unknowns using NSolve. But It's been too slow. I waited for more then an hour without any results. The code is: ...
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### Numerically finding a curve that satisfies an underdetermined set of equations

I am trying to determine a phase diagram along the lines of Fig 3. or Fig 4. of this pubilcation. The curves plotted are binodals and are determined by the conditions of equality of chemical ...
54 views

### NMinimze cant find points that satisfy constraints

NMinimize cant find solutions for a function which clearly has one. Setting a working precision resulted in some output, however with error messages about tolerance and precision. Heres my code. The ...
1 vote
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### Numerical Error using compile

I'm trying to compile a function and I'm running into the following error CompiledFunction::cfne : Numerical error encountered; proceeding with uncompiled evaluation. I think I have succeeded in ...
1 vote
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### NDSolve for Coupled ODE with parameters

Here I solved sys1 using NDSolve for the parameter m. I want to solve sys2 using NDSolve. But in sys2 I have a term consisting of the derivative of the solution obtained from sys1. I am stuck on how ...
110 views

### Performance improvements using Table and Compile

I'm converting a code from MatLab to Mathematica. It takes MatLab less than a second to compute it while its more than ten minutes in Mathematica. I was hoping to improve the performance. Here's a ...
35 views

### Dealing with Precision Issues in FindRoot for Complex Equations

I'm currently working on a Mathematica code that involves using the FindRoot function to find the poles of the scattering matrix in an one dimentional potetial well and for that, I need to find the ...
96 views

### Finding the Minimum of a Four-Variable Function

Greetings esteemed colleagues. I had previously posted regarding the minimisation of a function using Mathematica, and colleagues were kind enough to provide some useful suggestions that proved quite ...
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### To Chop or not to Chop

If I run the command ResourceFunction[ "GlobalMaxima"][{x*y + 2*y*z + 6*x, x^2 + y^2 + z^2 == 36}, {x, y, z}] This returns a closed form solution of ...
156 views

### Result of numerical computation representing a real physical quantity still contains a small imaginary components [closed]

I have been grappling with a physics calculation pertaining to thin film optics. I have been endeavouring to use transfer matrix calculations to determine optical reflectance. Attached below is the ...
111 views

### FindRoot error in NDSolve

I have two coupled differential equations as follows $$\frac{\partial }{\partial x}U(x,y) =2V(x,y),$$ $$\frac{\partial }{\partial y}V(x,y) =V(x,y)U(x,y)+1,$$ with ...
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### Why do the eigenvalues periodically change with successive increase in the consideration region?

When finding the eigenvalues and eigenfunctions of the system Hc[r, z] using NDEigensystem, the following issue arises: When ...
73 views

### How could a function in a cylindrical coordinate system be plotted? [duplicate]

Below is the code for finding the eigenfunctions and eigenvalues of a particle in the Coulomb field using NDEigensystem. The problem is solved in cylindrical coordinates ($\rho,\theta,z$; \$\rho \in [0,...