# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=97

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 98

---

## [Brute force bifurcation diagram - need help with stiff solver](https://discourse.julialang.org/t/brute-force-bifurcation-diagram-need-help-with-stiff-solver/94387)

<div class="topic-metadata">

**Author:** [@sdwfrost](https://discourse.julialang.org/u/sdwfrost)\
**Replies:** 15\
**Last updated:** [July 13, 2024, 1:33pm UTC](https://discourse.julialang.org/t/brute-force-bifurcation-diagram-need-help-with-stiff-solver/94387 "2024-07-13T13:33:46Z")

</div>

Hi All, I’m trying to reproduce a bifurcation diagram (brute force) computed using XPP-AUT. My code is here and the original XPP code from Krylova and Earn (2013) is here. The XPP code seems to give a nice bifurcation …

---

## [Time-varying parameter specification in DiscreteProblem?](https://discourse.julialang.org/t/time-varying-parameter-specification-in-discreteproblem/116975)

<div class="topic-metadata">

**Author:** [@sdwfrost](https://discourse.julialang.org/u/sdwfrost)\
**Replies:** 3\
**Last updated:** [July 13, 2024, 1:33pm UTC](https://discourse.julialang.org/t/time-varying-parameter-specification-in-discreteproblem/116975 "2024-07-13T13:33:41Z")

</div>

I have a simple DiscreteProblem, based on the SIR epidemic model. I’d like to pass a time-varying parameter to the model, to reduce \\beta by a factor v(t). As this is a discrete-time map, I’d like to define v as a vector…

---

## [Looking to parallelize (not parametrize) the solution to a large and highly stiff ODE system](https://discourse.julialang.org/t/looking-to-parallelize-not-parametrize-the-solution-to-a-large-and-highly-stiff-ode-system/116727)

<div class="topic-metadata">

**Author:** [@balaji\_sriram](https://discourse.julialang.org/u/balaji_sriram)\
**Replies:** 7\
**Last updated:** [July 13, 2024, 12:41pm UTC](https://discourse.julialang.org/t/looking-to-parallelize-not-parametrize-the-solution-to-a-large-and-highly-stiff-ode-system/116727 "2024-07-13T12:41:42Z")

</div>

I am solving a system of linear differential equations (of type \[dx/dt\]= \[Jacobian\]\*\[ x \] ) with about 1 million simultaneous differential equations. The system is highly stiff and the jacobian is sparse and banded. I us…

---

## [Using xor with JuMP and MiniZinc](https://discourse.julialang.org/t/using-xor-with-jump-and-minizinc/116519)

<div class="topic-metadata">

**Author:** [@remi-garcia](https://discourse.julialang.org/u/remi-garcia)\
**Replies:** 6\
**Last updated:** [July 13, 2024, 8:48am UTC](https://discourse.julialang.org/t/using-xor-with-jump-and-minizinc/116519 "2024-07-13T08:48:14Z")

</div>

Hi, With JuMP, I can create constraints with && and ||. I am trying to use xor and not. Is there a way to do this? I can do the following: using JuMP using MiniZinc model = Model(() -\> MiniZinc.Optimizer{Float64}("c…

---

## [It seems that MadNLP does not support general NLP problem](https://discourse.julialang.org/t/it-seems-that-madnlp-does-not-support-general-nlp-problem/116864)

<div class="topic-metadata">

**Author:** [@JackaChou](https://discourse.julialang.org/u/JackaChou)\
**Replies:** 7\
**Last updated:** [July 13, 2024, 5:50am UTC](https://discourse.julialang.org/t/it-seems-that-madnlp-does-not-support-general-nlp-problem/116864 "2024-07-13T05:50:05Z")

</div>

I recently used the solver MadNLP to solve the following NLP problem, but the terminal reported that it didn’t support this problem. Isn’t MadNLP a general NLP solver? using MadNLP, JuMP m = Model(() → MadNLP.Optimize…

---

## [Indicator constraints in IQP?](https://discourse.julialang.org/t/indicator-constraints-in-iqp/107587)

<div class="topic-metadata">

**Author:** [@Jeff\_Emanuel](https://discourse.julialang.org/u/Jeff_Emanuel)\
**Replies:** 6\
**Last updated:** [July 13, 2024, 3:32am UTC](https://discourse.julialang.org/t/indicator-constraints-in-iqp/107587 "2024-07-13T03:32:58Z")

</div>

The problem I’m trying to solve has grown to the point where it requires quadratic constraints and/or objective. When the problem was linear, I had used indicator constraints successfully. After switching to Juniper or…

---

## [Cyclic policy graph with fix number of cycles - SDDP.jl](https://discourse.julialang.org/t/cyclic-policy-graph-with-fix-number-of-cycles-sddp-jl/116546)

<div class="topic-metadata">

**Author:** [@Sorooshsa](https://discourse.julialang.org/u/Sorooshsa)\
**Replies:** 1\
**Last updated:** [July 13, 2024, 12:50am UTC](https://discourse.julialang.org/t/cyclic-policy-graph-with-fix-number-of-cycles-sddp-jl/116546 "2024-07-13T00:50:05Z")

</div>

Hi everyone, Can we design a cyclic linear policy graph in SDDP.jl with a fixed number of cycles? Let’s assume there are 4 nodes, where node 4 transitions to node 1 with a probability of 1. However, this cycle should re…

---

## [MOA-HiGHS Unsupported Objective Function](https://discourse.julialang.org/t/moa-highs-unsupported-objective-function/116672)

<div class="topic-metadata">

**Author:** [@jhannyj](https://discourse.julialang.org/u/jhannyj)\
**Replies:** 4\
**Last updated:** [July 13, 2024, 12:46am UTC](https://discourse.julialang.org/t/moa-highs-unsupported-objective-function/116672 "2024-07-13T00:46:39Z")

</div>

Hi all. I’m pretty new to Julia optimization. I have this problem: model = Model(HiGHS.Optimizer) @variable(model, x\[1:n\] \>= 0) @constraint(model, A' \* x .\>= f) @objective(model, Min, b' \* x) which works perfectly when…

---

## [How to use @expression macro with non-numeric indexes](https://discourse.julialang.org/t/how-to-use-expression-macro-with-non-numeric-indexes/116782)

<div class="topic-metadata">

**Author:** [@asuski](https://discourse.julialang.org/u/asuski)\
**Replies:** 2\
**Last updated:** [July 13, 2024, 12:41am UTC](https://discourse.julialang.org/t/how-to-use-expression-macro-with-non-numeric-indexes/116782 "2024-07-13T00:41:27Z")

</div>

Hi, I am building an optimization model where I would like to use JuMP expressions to smoothly add elements of constraints across different parts of the model. However, the sets I am working with and over which I am ini…

---

## [Jump/Ipopt: is it possibe to retrieve the numerical Jacobian at the optimal point?](https://discourse.julialang.org/t/jump-ipopt-is-it-possibe-to-retrieve-the-numerical-jacobian-at-the-optimal-point/116896)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [July 13, 2024, 12:16am UTC](https://discourse.julialang.org/t/jump-ipopt-is-it-possibe-to-retrieve-the-numerical-jacobian-at-the-optimal-point/116896 "2024-07-13T00:16:45Z")

</div>

Hello, on a nonlinear solved optimization problem (JuMP/Ipopt) is it possible to retrieve the values of the Jacobian matrix at the returned optimal point ?

---

## [Is GLPK still maintained/relevant?](https://discourse.julialang.org/t/is-glpk-still-maintained-relevant/116950)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 3\
**Last updated:** [July 13, 2024, 12:13am UTC](https://discourse.julialang.org/t/is-glpk-still-maintained-relevant/116950 "2024-07-13T00:13:13Z")

</div>

Is GLPK (the lib itself, not the Julia wrapper) still maintained and relevant ? I can’t find any activity after 2020 Also wonder if it it still relevant or newer packages as HiGHS are the way to go nowadays…

---

## [32-bit TIFs?](https://discourse.julialang.org/t/32-bit-tifs/116931)

<div class="topic-metadata">

**Author:** [@EricChameroy](https://discourse.julialang.org/u/EricChameroy)\
**Replies:** 2\
**Last updated:** [July 12, 2024, 5:47pm UTC](https://discourse.julialang.org/t/32-bit-tifs/116931 "2024-07-12T17:47:49Z")

</div>

Hello, Is it possible to save images as 32-bit TIFs? When attempting to save Float32 matrices using TiffImages.jl, I only get 8-bit TIFs. Thanks!

---

## [Nan value with parallelization on Trixi.jl Taylor Green Vortex test case](https://discourse.julialang.org/t/nan-value-with-parallelization-on-trixi-jl-taylor-green-vortex-test-case/116765)

<div class="topic-metadata">

**Author:** [@Kelian\_Renoux](https://discourse.julialang.org/u/Kelian_Renoux)\
**Replies:** 4\
**Last updated:** [July 12, 2024, 11:14am UTC](https://discourse.julialang.org/t/nan-value-with-parallelization-on-trixi-jl-taylor-green-vortex-test-case/116765 "2024-07-12T11:14:17Z")

</div>

Hello, I am trying to run the p4est Taylor Green Vortex test case on multiple processors but I am facing really weird instabilities. After the first iteration, all values of density, velocity and pressure are Nan. This i…

---

## [OpenFoam blockMesh output as Trixi input](https://discourse.julialang.org/t/openfoam-blockmesh-output-as-trixi-input/116875)

<div class="topic-metadata">

**Author:** [@Domenico\_Lahaye](https://discourse.julialang.org/u/Domenico_Lahaye)\
**Replies:** 3\
**Last updated:** [July 12, 2024, 10:19am UTC](https://discourse.julialang.org/t/openfoam-blockmesh-output-as-trixi-input/116875 "2024-07-12T10:19:06Z")

</div>

What is require for Trixi to read the meshes that blockMesh in OpenFoam generates? Congrats for a wonderful talk at JuliaCon!

---

## [Linsolve vs. PETSc for transient laminar Navier - Stokes](https://discourse.julialang.org/t/linsolve-vs-petsc-for-transient-laminar-navier-stokes/116876)

<div class="topic-metadata">

**Author:** [@Domenico\_Lahaye](https://discourse.julialang.org/u/Domenico_Lahaye)\
**Replies:** 1\
**Last updated:** [July 12, 2024, 9:47am UTC](https://discourse.julialang.org/t/linsolve-vs-petsc-for-transient-laminar-navier-stokes/116876 "2024-07-12T09:47:18Z")

</div>

The question that follows was phrased at JuliaCon: given: suppose solving a 2D / 3D transient laminar Navier-Stokes problems (lid-driven cavity, flow part cylinder or airfoil) using Gridap, Trixi or similar how do the …

---

## [Legend with many labels can't fit in output](https://discourse.julialang.org/t/legend-with-many-labels-cant-fit-in-output/116947)

<div class="topic-metadata">

**Author:** [@AtomsForHire](https://discourse.julialang.org/u/AtomsForHire)\
**Replies:** 2\
**Last updated:** [July 12, 2024, 8:09am UTC](https://discourse.julialang.org/t/legend-with-many-labels-cant-fit-in-output/116947 "2024-07-12T08:09:49Z")

</div>

Hello, I have a plot with many lines, and a legend with labels for all those lines. Here is an example output. using CairoMakie set\_theme!(theme\_latexfonts()) update\_theme!( palette=(color=ColorSchemes.glasbey\_cat…

---

## [External functions in GPU ODE example](https://discourse.julialang.org/t/external-functions-in-gpu-ode-example/116719)

<div class="topic-metadata">

**Author:** [@xztt](https://discourse.julialang.org/u/xztt)\
**Replies:** 7\
**Last updated:** [July 11, 2024, 9:07pm UTC](https://discourse.julialang.org/t/external-functions-in-gpu-ode-example/116719 "2024-07-11T21:07:36Z")

</div>

Hi all, I have tried adapting the DiffEqGPU example to my own example which depends on some external functions. The error is quite dense so if someone could point me in the right direction this would be a big help. Exa…

---

## [Scaled diagonally dominant programming](https://discourse.julialang.org/t/scaled-diagonally-dominant-programming/116853)

<div class="topic-metadata">

**Author:** [@Khashayar-Neshat](https://discourse.julialang.org/u/Khashayar-Neshat)\
**Replies:** 2\
**Last updated:** [July 11, 2024, 8:47pm UTC](https://discourse.julialang.org/t/scaled-diagonally-dominant-programming/116853 "2024-07-11T20:47:52Z")

</div>

In polynomial optimization, one can check the certificate of nonnegativity with sums of squares (SOS) optimization which leads to semidefinite programming. Another more conservative approach is to use SDSOS optimization …

---

## [Original until() function](https://discourse.julialang.org/t/original-until-function/116903)

<div class="topic-metadata">

**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 2\
**Last updated:** [July 11, 2024, 12:33pm UTC](https://discourse.julialang.org/t/original-until-function/116903 "2024-07-11T12:33:38Z")

</div>

Hello everyone, Can someone point me to location of this function until() which is used as follow while until(s, t0, n, model) ....something.... end in agents.jl. I want to check the original function. I was lookin…

---

## [ModelingToolkit: linearization failure](https://discourse.julialang.org/t/modelingtoolkit-linearization-failure/116899)

<div class="topic-metadata">

**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 1\
**Last updated:** [July 11, 2024, 12:33pm UTC](https://discourse.julialang.org/t/modelingtoolkit-linearization-failure/116899 "2024-07-11T12:33:08Z")

</div>

I’m trying to linearize a “complex” (for me) ModelingToolkit \[MTK\] model consisting of several layers of components that I have written. My components do not use ports (I’m in the process of learning this), and I try to …

---

## [Passing \`::Type{InconcreteType}\` to CUDA kernel](https://discourse.julialang.org/t/passing-type-inconcretetype-to-cuda-kernel/116833)

<div class="topic-metadata">

**Author:** [@hexaeder](https://discourse.julialang.org/u/hexaeder)\
**Replies:** 2\
**Last updated:** [July 11, 2024, 12:04pm UTC](https://discourse.julialang.org/t/passing-type-inconcretetype-to-cuda-kernel/116833 "2024-07-11T12:04:32Z")

</div>

Hello, I have some kernels that share a lot of code but specialize in the end based on some type of AbstractAction in the MWE below Addition or Multiplication. Those concrete actions have some nonbitstype metadata, whic…

---

## [Performance of primal versus dual forms in JuMP](https://discourse.julialang.org/t/performance-of-primal-versus-dual-forms-in-jump/116633)

<div class="topic-metadata">

**Author:** [@araujoms](https://discourse.julialang.org/u/araujoms)\
**Replies:** 6\
**Last updated:** [July 11, 2024, 10:54am UTC](https://discourse.julialang.org/t/performance-of-primal-versus-dual-forms-in-jump/116633 "2024-07-11T10:54:19Z")

</div>

I’m trying to determine the most efficient form of modelling a problem for a package (QuantumNPA.jl). The natural way of writing the problem is in the dual or geometric form (see here for nomenclature); however, this giv…

---

## [CUDA.compute\_sanitizer() method not defined](https://discourse.julialang.org/t/cuda-compute-sanitizer-method-not-defined/116888)

<div class="topic-metadata">

**Author:** [@alexpan5](https://discourse.julialang.org/u/alexpan5)\
**Replies:** 1\
**Last updated:** [July 11, 2024, 10:18am UTC](https://discourse.julialang.org/t/cuda-compute-sanitizer-method-not-defined/116888 "2024-07-11T10:18:31Z")

</div>

I want to use compute-sanitizer to look into a memory error, but when I run: julia\> using CUDA julia\> CUDA.compute\_sanitizer() I just get ERROR: UndefVarError: compute\_sanitizer not defined. CUDA.compute\_sanitizer\_cmd…

---

## [Global Constrained Nonlinear Optimization](https://discourse.julialang.org/t/global-constrained-nonlinear-optimization/111972)

<div class="topic-metadata">

**Author:** [@zaccazy](https://discourse.julialang.org/u/zaccazy)\
**Replies:** 11\
**Last updated:** [July 11, 2024, 7:41am UTC](https://discourse.julialang.org/t/global-constrained-nonlinear-optimization/111972 "2024-07-11T07:41:50Z")

</div>

I am looking for a global optimizer to solve a nonlinear problem with three variables and two nonlinear inequality constraints. So far, everything I’ve tried delivers local solutions, i.e. solution heavily relies on the …

---

## [Using latest TermInterface for custom types in MetaTheory](https://discourse.julialang.org/t/using-latest-terminterface-for-custom-types-in-metatheory/116885)

<div class="topic-metadata">

**Author:** [@wgm](https://discourse.julialang.org/u/wgm)\
**Replies:** 2\
**Last updated:** [July 10, 2024, 10:50pm UTC](https://discourse.julialang.org/t/using-latest-terminterface-for-custom-types-in-metatheory/116885 "2024-07-10T22:50:10Z")

</div>

Is there an example of using TermInterface v2.0 with the ale/3.0 branch of MetaTheory for working with custom types? I’m looking for something like Interfacing with Metatheory.jl · Metatheory.jl that works with the lates…

---

## [A bug about JuMP.jl](https://discourse.julialang.org/t/a-bug-about-jump-jl/116870)

<div class="topic-metadata">

**Author:** [@lionisxn](https://discourse.julialang.org/u/lionisxn)\
**Replies:** 1\
**Last updated:** [July 10, 2024, 4:29pm UTC](https://discourse.julialang.org/t/a-bug-about-jump-jl/116870 "2024-07-10T16:29:41Z")

</div>

I was wondering whether there exist bugs of calling for "value(function, expr) ". My codes are like this: M = Model() @variable(M, x) @variable(M, y) @NLconstraint(M, con, x + x\*y^2 - 3 \>= 0) t = all\_constraints(M;…

---

## [Complexity JuMP constraints](https://discourse.julialang.org/t/complexity-jump-constraints/116773)

<div class="topic-metadata">

**Author:** [@gustave\_Robichon](https://discourse.julialang.org/u/gustave_Robichon)\
**Replies:** 5\
**Last updated:** [July 10, 2024, 3:00pm UTC](https://discourse.julialang.org/t/complexity-jump-constraints/116773 "2024-07-10T15:00:40Z")

</div>

Hello there :slight\_smile: I have a SDP problem with a SemiDefinite matrix M of size n \\times n. I have a number c of constraints. There is a time of preparation, then the problem is given to the SDP solver (for example…

---

## [Matrix Constraints in JuMP](https://discourse.julialang.org/t/matrix-constraints-in-jump/116663)

<div class="topic-metadata">

**Author:** [@Gagan\_Meena](https://discourse.julialang.org/u/Gagan_Meena)\
**Replies:** 3\
**Last updated:** [July 10, 2024, 12:13pm UTC](https://discourse.julialang.org/t/matrix-constraints-in-jump/116663 "2024-07-10T12:13:08Z")

</div>

Can I write matrix constraints in JUMP using @constraints macro? While writing this flow constraint Bd\*A\*δ .== f as one of the constraints in the @constraints macro, I am getting the following error. ERROR: MethodErro…

---

## [Iterator over all random elements without materialization](https://discourse.julialang.org/t/iterator-over-all-random-elements-without-materialization/116819)

<div class="topic-metadata">

**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 9\
**Last updated:** [July 10, 2024, 5:45am UTC](https://discourse.julialang.org/t/iterator-over-all-random-elements-without-materialization/116819 "2024-07-10T05:45:43Z")

</div>

Hi All, I have a specific question. I am working on abductive explanation of neural networks, f. Abductive explanation is a subset (let’s denote indices ii) of the input x guaranteeing that the model (neural network) pr…

---

## [Use ControlSystemIdentification.jl for a ModelingToolkit.jl model](https://discourse.julialang.org/t/use-controlsystemidentification-jl-for-a-modelingtoolkit-jl-model/116588)

<div class="topic-metadata">

**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 7\
**Last updated:** [July 10, 2024, 4:21am UTC](https://discourse.julialang.org/t/use-controlsystemidentification-jl-for-a-modelingtoolkit-jl-model/116588 "2024-07-10T04:21:05Z")

</div>

Hi, I have an LTI model defined in ModelingToolkit.jl: @named T\_a\_out = TimeVaryingFunction(input\_funcs\[:T\_a\]) @named Φ\_hp\_out = TimeVaryingFunction(input\_funcs\[:Φ\_hp\]) @named Φ\_cv\_out = TimeVaryingFunction(input\_funcs…

[Previous page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=96)

[Next page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=98)