# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=206

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

**Page:** 207

---

## [How to optimize Jacobian ForwardDiff.jl](https://discourse.julialang.org/t/how-to-optimize-jacobian-forwarddiff-jl/96177)

<div class="topic-metadata">

**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 2\
**Last updated:** [March 20, 2023, 8:20am UTC](https://discourse.julialang.org/t/how-to-optimize-jacobian-forwarddiff-jl/96177 "2023-03-20T08:20:41Z")

</div>

Hello, I manual calculate Jacobian for the system function TM(u, p, t) U(y) = p\[8\] + p\[9\] / ( 1.0 + exp( -50.0 \* (y - p\[7\]) ) ) σ(x) = 1.0 / ( 1.0 + exp( -20.0 \* (x-p\[6\]) ) ) du1 = (-u\[1\] + p\[1\] \* log( 1.0 +…

---

## [Can you use Gurobi's \`ObjNRelTol\` and \`ObjNAbsTol\`?](https://discourse.julialang.org/t/can-you-use-gurobis-objnreltol-and-objnabstol/96327)

<div class="topic-metadata">

**Author:** [@gleyland](https://discourse.julialang.org/u/gleyland)\
**Replies:** 3\
**Last updated:** [March 20, 2023, 7:38am UTC](https://discourse.julialang.org/t/can-you-use-gurobis-objnreltol-and-objnabstol/96327 "2023-03-20T07:38:59Z")

</div>

Hi, As for the subject. We’ve tried MOI.set(grb, Gurobi.MultiObjectiveAttribute("ObjNRelTol", 0.001)) But we got ERROR: LoadError: UndefVarError: MultiObjectiveAttribute not defined We’re on Gurobi 0.11.5, which se…

---

## [Defining variables in JuMP](https://discourse.julialang.org/t/defining-variables-in-jump/95843)

<div class="topic-metadata">

**Author:** [@kevinqiao](https://discourse.julialang.org/u/kevinqiao)\
**Replies:** 4\
**Last updated:** [March 20, 2023, 2:46am UTC](https://discourse.julialang.org/t/defining-variables-in-jump/95843 "2023-03-20T02:46:46Z")

</div>

Hello, I have a question about defining variables in JuMP, normally, the variables are defined as @variable(model, testContinusVar) @variable(model, testIntegerVar, Int) @variable(model, testBinaryVar, Bin) And what i…

---

## [Use MPI with iJulia](https://discourse.julialang.org/t/use-mpi-with-ijulia/96319)

<div class="topic-metadata">

**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 1\
**Last updated:** [March 19, 2023, 8:43pm UTC](https://discourse.julialang.org/t/use-mpi-with-ijulia/96319 "2023-03-19T20:43:01Z")

</div>

Is there an easy/recommended way to use iJulia with MPI? I see this has (somewhat) been asked in the past. But I’m wondering if anything has changed in the last few years (which is quite a bit of time for Julia…)

---

## [Warm starting Xpress with a full basis using JuMP](https://discourse.julialang.org/t/warm-starting-xpress-with-a-full-basis-using-jump/96216)

<div class="topic-metadata">

**Author:** [@Diego](https://discourse.julialang.org/u/Diego)\
**Replies:** 6\
**Last updated:** [March 19, 2023, 8:40pm UTC](https://discourse.julialang.org/t/warm-starting-xpress-with-a-full-basis-using-jump/96216 "2023-03-19T20:40:53Z")

</div>

Dear all, I have tried setting initial values/duals of similar problems in JuMP/Xpress for LP problems but we have not been very successful for LP, for MIP we have been though. I was wondering whether Xpress.writebasis…

---

## [PlotlyJS doesn't implement orthographic projection option](https://discourse.julialang.org/t/plotlyjs-doesnt-implement-orthographic-projection-option/96203)

<div class="topic-metadata">

**Author:** [@bhalpin](https://discourse.julialang.org/u/bhalpin)\
**Replies:** 6\
**Last updated:** [March 19, 2023, 2:20pm UTC](https://discourse.julialang.org/t/plotlyjs-doesnt-implement-orthographic-projection-option/96203 "2023-03-19T14:20:03Z")

</div>

PlotlyJS has an option for orthographic projection rather than the default “perspective” projection. It is described in the docs here: https://docs.juliaplots.org/stable/gallery/plotlyjs/generated/plotlyjs-ref060/ The …

---

## [PlotlyJS confidence band bug?](https://discourse.julialang.org/t/plotlyjs-confidence-band-bug/96287)

<div class="topic-metadata">

**Author:** [@Igor\_Douven](https://discourse.julialang.org/u/Igor_Douven)\
**Replies:** 6\
**Last updated:** [March 19, 2023, 12:14pm UTC](https://discourse.julialang.org/t/plotlyjs-confidence-band-bug/96287 "2023-03-19T12:14:57Z")

</div>

Hi all, I’m trying to plot confidence bands using PlotlyJS.jl. It’s almost working, except that while the lines all start at x = 50, the confidence bands, for some reason, start at x = 0. This is for instance how I defi…

---

## [High allocations count for TwoPointBVProblem in DifferentialEquations.jl](https://discourse.julialang.org/t/high-allocations-count-for-twopointbvproblem-in-differentialequations-jl/96296)

<div class="topic-metadata">

**Author:** [@Hawkes](https://discourse.julialang.org/u/Hawkes)\
**Replies:** 4\
**Last updated:** [March 19, 2023, 11:22am UTC](https://discourse.julialang.org/t/high-allocations-count-for-twopointbvproblem-in-differentialequations-jl/96296 "2023-03-19T11:22:52Z")

</div>

Hi, I’m currently trying to port some simulation code from Python to Julia. The Python version uses scipy’s solve\_bvp function to solve a two point boundary value problem. I am using DifferentialEquations.jl to accompl…

---

## [Can't train simple net what am I doing wrong?](https://discourse.julialang.org/t/cant-train-simple-net-what-am-i-doing-wrong/96094)

<div class="topic-metadata">

**Author:** [@Fabrice\_Rosay](https://discourse.julialang.org/u/Fabrice_Rosay)\
**Replies:** 1\
**Last updated:** [March 18, 2023, 10:19pm UTC](https://discourse.julialang.org/t/cant-train-simple-net-what-am-i-doing-wrong/96094 "2023-03-18T22:19:25Z")

</div>

Here is a minimal working example: function ResNetBlock(n::Int) return Chain( Conv((3, 3), n =\> n, relu; pad=1, stride=1), BatchNorm(n, relu), Conv((3, 3), n =\> n; pad=1, stride=1), B…

---

## [Simple Model for CIFAR-10 using Flux not converging](https://discourse.julialang.org/t/simple-model-for-cifar-10-using-flux-not-converging/96168)

<div class="topic-metadata">

**Author:** [@iskyd](https://discourse.julialang.org/u/iskyd)\
**Replies:** 1\
**Last updated:** [March 18, 2023, 10:10pm UTC](https://discourse.julialang.org/t/simple-model-for-cifar-10-using-flux-not-converging/96168 "2023-03-18T22:10:14Z")

</div>

I’m trying to train a simple model on the CIFAR-10 dataset. I’m using the model proposed by the flux documentation on cifar-10 found here: Deep Learning with Julia & Flux: A 60 Minute Blitz · Flux This is my code. Whe…

---

## [RNG in DiscreteProblem solver](https://discourse.julialang.org/t/rng-in-discreteproblem-solver/95929)

<div class="topic-metadata">

**Author:** [@sdwfrost](https://discourse.julialang.org/u/sdwfrost)\
**Replies:** 3\
**Last updated:** [March 18, 2023, 10:48am UTC](https://discourse.julialang.org/t/rng-in-discreteproblem-solver/95929 "2023-03-18T10:48:46Z")

</div>

Hi everyone, I have a DiscreteProblem that uses a random number generator, and I’d like to make it reproducible. In the solver for SDEProblems, I can specify a seed (if not an RNG) - do I need to compose a new init/step!…

---

## [Solving ODEs in parallel on a supercomputer](https://discourse.julialang.org/t/solving-odes-in-parallel-on-a-supercomputer/95637)

<div class="topic-metadata">

**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 8\
**Last updated:** [March 18, 2023, 4:01am UTC](https://discourse.julialang.org/t/solving-odes-in-parallel-on-a-supercomputer/95637 "2023-03-18T04:01:01Z")

</div>

Hi everyone, I would like to solve ODEs in parallel on a supercomputer. I can use one or more nodes and multiple cores per node. There is also the option for node sharing. The job scheduler for the supercomputer is slur…

---

## [Error in DiffEqSensitivity: no method for similar of Duals](https://discourse.julialang.org/t/error-in-diffeqsensitivity-no-method-for-similar-of-duals/92457)

<div class="topic-metadata">

**Author:** [@AndreaRH](https://discourse.julialang.org/u/AndreaRH)\
**Replies:** 5\
**Last updated:** [March 17, 2023, 8:55pm UTC](https://discourse.julialang.org/t/error-in-diffeqsensitivity-no-method-for-similar-of-duals/92457 "2023-03-17T20:55:10Z")

</div>

Hello! I’m trying to understand how to use DiffEqSensitivity.jl and started with a toy example but ran into trouble when defining a ODEForwardSensitivityProblem. My cost functional is the average of a filtered (low-pass…

---

## [Does anyone know how to solve MI-SDP problem in Julia?](https://discourse.julialang.org/t/does-anyone-know-how-to-solve-mi-sdp-problem-in-julia/9725)

<div class="topic-metadata">

**Author:** [@Sharabh\_Shukla](https://discourse.julialang.org/u/Sharabh_Shukla)\
**Replies:** 13\
**Last updated:** [March 17, 2023, 9:59pm UTC](https://discourse.julialang.org/t/does-anyone-know-how-to-solve-mi-sdp-problem-in-julia/9725 "2023-03-17T21:59:04Z")

</div>

I am working on an MI-SDP model and I have no idea how to solve it using Julia. I tried solving the model in convex using MOSEK as a solver, it turns out it failed, throwing some nasty error. Any ideas on solving Mixed …

---

## [Ways to save and load JuMP models from/to disk or memory](https://discourse.julialang.org/t/ways-to-save-and-load-jump-models-from-to-disk-or-memory/33465)

<div class="topic-metadata">

**Author:** [@Diego](https://discourse.julialang.org/u/Diego)\
**Replies:** 31\
**Last updated:** [March 17, 2023, 9:58pm UTC](https://discourse.julialang.org/t/ways-to-save-and-load-jump-models-from-to-disk-or-memory/33465 "2023-03-17T21:58:32Z")

</div>

Dear team, Is there a way to save JuMP models to disk and then load them back and then just perform some modifications? Thank you!

---

## [Easy way to scale model in JuMP?](https://discourse.julialang.org/t/easy-way-to-scale-model-in-jump/96212)

<div class="topic-metadata">

**Author:** [@shakedregev](https://discourse.julialang.org/u/shakedregev)\
**Replies:** 2\
**Last updated:** [March 17, 2023, 5:34pm UTC](https://discourse.julialang.org/t/easy-way-to-scale-model-in-jump/96212 "2023-03-17T17:34:20Z")

</div>

I’m developing a linear solver for an optimization solver that requires a scaled constraint matrix. I am solving an LP, so the constraint matrix is constant. I would like to be able to scale the constraints within the op…

---

## [How to find equation when i have points?](https://discourse.julialang.org/t/how-to-find-equation-when-i-have-points/96240)

<div class="topic-metadata">

**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 7\
**Last updated:** [March 17, 2023, 2:31pm UTC](https://discourse.julialang.org/t/how-to-find-equation-when-i-have-points/96240 "2023-03-17T14:31:51Z")

</div>

I have points and need to get equation of these points. I try to use wolfram and another online services and all result is bad.

---

## [Replace Rmath RNGs](https://discourse.julialang.org/t/replace-rmath-rngs/96231)

<div class="topic-metadata">

**Author:** [@ArunSanganal](https://discourse.julialang.org/u/ArunSanganal)\
**Replies:** 1\
**Last updated:** [March 17, 2023, 7:25am UTC](https://discourse.julialang.org/t/replace-rmath-rngs/96231 "2023-03-17T07:25:04Z")

</div>

I have gone through issue#294\[1\], and the PR\[2\], matbesancon, who made the PR wrote the #TODO for every unchecked distribution in the issue. (Hypergeometric, NegativeBinomial, NoncentralChisq, poison, and skellam) but ap…

---

## [Mosek install broken on osx](https://discourse.julialang.org/t/mosek-install-broken-on-osx/96226)

<div class="topic-metadata">

**Author:** [@richardrl](https://discourse.julialang.org/u/richardrl)\
**Replies:** 2\
**Last updated:** [March 17, 2023, 7:03am UTC](https://discourse.julialang.org/t/mosek-install-broken-on-osx/96226 "2023-03-17T07:03:09Z")

</div>

\*\*(@v1.8) pkg\>\*\* add MosekTools, Mosek, Convex, Images, DelimitedFiles, Gadfly \*\*Updating\*\* registry at \`~/.julia/registries/General.toml\` \*\*Resolving\*\* package versions... \*\*Installed\*\* MosekTools ─ v0.13.2 \*\*Instal…

---

## [MPI RMA with CUDA](https://discourse.julialang.org/t/mpi-rma-with-cuda/96219)

<div class="topic-metadata">

**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 2\
**Last updated:** [March 17, 2023, 4:47am UTC](https://discourse.julialang.org/t/mpi-rma-with-cuda/96219 "2023-03-17T04:47:21Z")

</div>

I’m interested in using MPI RMA (i.e. one-sided operations) with native CuArrays. From the MPI.jl documentation, we read: \[CuArrays\] may also work with one-sided operations, but these are not often supported Could s…

---

## [Plots.jl clean scientific formatting](https://discourse.julialang.org/t/plots-jl-clean-scientific-formatting/38112)

<div class="topic-metadata">

**Author:** [@DR59](https://discourse.julialang.org/u/DR59)\
**Replies:** 9\
**Last updated:** [March 17, 2023, 1:07am UTC](https://discourse.julialang.org/t/plots-jl-clean-scientific-formatting/38112 "2023-03-17T01:07:02Z")

</div>

Suppose I have a plot p. If I want to change the y-axis to scientific formatting, I can do: plot!(p, yformatter = :scientific) Now a tick label that was previously: 30000, becomes 3x10^4. However I don’t want each sin…

---

## [Reading JuMP model "lower bound already set"](https://discourse.julialang.org/t/reading-jump-model-lower-bound-already-set/96156)

<div class="topic-metadata">

**Author:** [@shakedregev](https://discourse.julialang.org/u/shakedregev)\
**Replies:** 7\
**Last updated:** [March 16, 2023, 9:49pm UTC](https://discourse.julialang.org/t/reading-jump-model-lower-bound-already-set/96156 "2023-03-16T21:49:20Z")

</div>

Writing the model like this works model = JuMP.Model(Clarabel.Optimizer) \*set variables and contraints\* write\_to\_file(model, "my\_model.lp") The model is also solved correctly by Clarabel. However, problems occur when I…

---

## [How to create a variable that is Hermitian but not PSD?](https://discourse.julialang.org/t/how-to-create-a-variable-that-is-hermitian-but-not-psd/96170)

<div class="topic-metadata">

**Author:** [@araujoms](https://discourse.julialang.org/u/araujoms)\
**Replies:** 1\
**Last updated:** [March 16, 2023, 7:43pm UTC](https://discourse.julialang.org/t/how-to-create-a-variable-that-is-hermitian-but-not-psd/96170 "2023-03-16T19:43:00Z")

</div>

I need to create a Hermitian matrix that is not PSD for solving a specific problem. How do I do that? The obvious syntax @variable(model, x\[1:d,1:d\], Hermitian) gives an error, unlike @variable(model, x\[1:d,1:d\], Symmetr…

---

## [MethodError: Cannot \`convert\` an object of type Missing to an object of type Float64](https://discourse.julialang.org/t/methoderror-cannot-convert-an-object-of-type-missing-to-an-object-of-type-float64/96160)

<div class="topic-metadata">

**Author:** [@Saba\_ghasemi](https://discourse.julialang.org/u/Saba_ghasemi)\
**Replies:** 4\
**Last updated:** [March 16, 2023, 7:42pm UTC](https://discourse.julialang.org/t/methoderror-cannot-convert-an-object-of-type-missing-to-an-object-of-type-float64/96160 "2023-03-16T19:42:15Z")

</div>

I tried to solve a very big optimization problem (MIQCP), and the error MethodError: Cannot convert an object of type Missing to an object of type Float64 Closest candidates are: convert(::Type{T}, ::T) where T\<:Numbe…

---

## [MultiObjectiveAlgorithms.EpsilonConstraint runs infinitely](https://discourse.julialang.org/t/multiobjectivealgorithms-epsilonconstraint-runs-infinitely/96178)

<div class="topic-metadata">

**Author:** [@mdogan](https://discourse.julialang.org/u/mdogan)\
**Replies:** 3\
**Last updated:** [March 16, 2023, 7:41pm UTC](https://discourse.julialang.org/t/multiobjectivealgorithms-epsilonconstraint-runs-infinitely/96178 "2023-03-16T19:41:32Z")

</div>

I am trying to solve an optimization problem (obtain the efficient frontier of optimal portfolios by maximizing expected return per given level of sharpe ratio). However, the solution runs infinitely (though not always, …

---

## [Sequential AC power flow using PowerModels.jl](https://discourse.julialang.org/t/sequential-ac-power-flow-using-powermodels-jl/96183)

<div class="topic-metadata">

**Author:** [@sstroemer](https://discourse.julialang.org/u/sstroemer)\
**Replies:** 1\
**Last updated:** [March 16, 2023, 6:22pm UTC](https://discourse.julialang.org/t/sequential-ac-power-flow-using-powermodels-jl/96183 "2023-03-16T18:22:43Z")

</div>

I am trying to run repeated AC power flow calculations for a large grid using PowerModels.jl. Digging through the code revealed that there is some way to efficiently run successive power flow solves, but I couldn’t reall…

---

## [Parallelize GSA on continuous outputs](https://discourse.julialang.org/t/parallelize-gsa-on-continuous-outputs/95964)

<div class="topic-metadata">

**Author:** [@xztt](https://discourse.julialang.org/u/xztt)\
**Replies:** 12\
**Last updated:** [March 16, 2023, 5:29pm UTC](https://discourse.julialang.org/t/parallelize-gsa-on-continuous-outputs/95964 "2023-03-16T17:29:51Z")

</div>

Hi there, I am just wondering how I could adapt the GSA example in the docs such that it performs Sobol analysis on the continuous outputs instead of the discrete outputs. sol\[1,:\] & sol\[2,:\] I have tried multiple diff…

---

## [Help with optimizing a particle filter in SciML](https://discourse.julialang.org/t/help-with-optimizing-a-particle-filter-in-sciml/96138)

<div class="topic-metadata">

**Author:** [@sdwfrost](https://discourse.julialang.org/u/sdwfrost)\
**Replies:** 8\
**Last updated:** [March 16, 2023, 3:48pm UTC](https://discourse.julialang.org/t/help-with-optimizing-a-particle-filter-in-sciml/96138 "2023-03-16T15:48:31Z")

</div>

Hi everyone, I’m trying to put together a demonstration of a very simple particle filter for my repository https://github.com/epirecipes/sir-julia. This involves: Setting up an array of simulations. Simulating for a s…

---

## [AMDGPU.jl status](https://discourse.julialang.org/t/amdgpu-jl-status/71191)

<div class="topic-metadata">

**Author:** [@torrance](https://discourse.julialang.org/u/torrance)\
**Replies:** 11\
**Last updated:** [March 16, 2023, 1:46pm UTC](https://discourse.julialang.org/t/amdgpu-jl-status/71191 "2023-03-16T13:46:10Z")

</div>

I’m beginning a fairly large project that is destined to run on a newly commissioned HPC cluster that will be using AMD’s Milan CPUs and MI250 GPUs. Once we have proven the algorithm works on the CPU it will be ported to…

---

## [Integrating Hamilton's equations](https://discourse.julialang.org/t/integrating-hamiltons-equations/96147)

<div class="topic-metadata">

**Author:** [@roi.holtzman](https://discourse.julialang.org/u/roi.holtzman)\
**Replies:** 4\
**Last updated:** [March 16, 2023, 1:24pm UTC](https://discourse.julialang.org/t/integrating-hamiltons-equations/96147 "2023-03-16T13:24:13Z")

</div>

I want to integrate the equations of motion of a classical physical system. My Hamiltonian is changing in time, and actually, I am interested in considering the general case where it is not necessarily of the form H(q, …

[Previous page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=205)

[Next page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=207)