# Latest

**URL:** https://discourse.julialang.org/latest.md?page=589

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

**Page:** 590

---

## [Matrix inversion inside JuMP objective](https://discourse.julialang.org/t/matrix-inversion-inside-jump-objective/104214)

<div class="topic-metadata">

**Author:** [@lsablon](https://discourse.julialang.org/u/lsablon)\
**Replies:** 4\
**Last updated:** [September 26, 2023, 8:05pm UTC](https://discourse.julialang.org/t/matrix-inversion-inside-jump-objective/104214 "2023-09-26T20:05:07Z")

</div>

Hello, I am trying to solve the following problem using JuMP: find a set of values u subject to different linear constraints (namely positivity and mass conservation) such that the distance to a know solution of a linea…

---

## [Least squares in julia](https://discourse.julialang.org/t/least-squares-in-julia/104279)

<div class="topic-metadata">

**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 7\
**Last updated:** [September 26, 2023, 7:22pm UTC](https://discourse.julialang.org/t/least-squares-in-julia/104279 "2023-09-26T19:22:23Z")

</div>

Hello, good afternoon, I’m facing issues to solve least squares in julia using qr decomposition. numcourses = \[13,4,12,3,14,13,12,9,11,7,13,11,9,2,5,7,10,0,9,7\] happiness = \[70,25,54,21,80,68,84,62,57,40,60,64,45,38,5…

---

## [Help removing allocations for "enrichment score" function](https://discourse.julialang.org/t/help-removing-allocations-for-enrichment-score-function/104273)

<div class="topic-metadata">

**Author:** [@kevbonham](https://discourse.julialang.org/u/kevbonham)\
**Replies:** 1\
**Last updated:** [September 26, 2023, 6:57pm UTC](https://discourse.julialang.org/t/help-removing-allocations-for-enrichment-score-function/104273 "2023-09-26T18:57:12Z")

</div>

I have a function that calculates an “enrichment score” for a set of values - basically, the skew of in-set vs out-of-set values. A naive implementation (it’s sort of a literal transcription of the method) looks like thi…

---

## [What does "publication-quality plots" mean?](https://discourse.julialang.org/t/what-does-publication-quality-plots-mean/104270)

<div class="topic-metadata">

**Author:** [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Replies:** 4\
**Last updated:** [September 26, 2023, 4:42pm UTC](https://discourse.julialang.org/t/what-does-publication-quality-plots-mean/104270 "2023-09-26T16:42:55Z")

</div>

I’ve seen this term many times here and each time got a feeling I live in a different world, where there is nothing special for a plot to be published. So I just took a small random sample of journal articles from my Zot…

---

## [When using seriestype=:scatter, create individual labels for each dot?](https://discourse.julialang.org/t/when-using-seriestype-scatter-create-individual-labels-for-each-dot/104233)

<div class="topic-metadata">

**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 5\
**Last updated:** [September 26, 2023, 3:50pm UTC](https://discourse.julialang.org/t/when-using-seriestype-scatter-create-individual-labels-for-each-dot/104233 "2023-09-26T15:50:29Z")

</div>

I am using Plot recipes to create a plot overload for a special type of input. The result is a scatter plot with something like: @recipe function f(ms::MyStruct) seriestype --\> :scatter ms.x\_vals, ms.y\_vals end…

---

## [A sparse matrix cannot be indexed by a SVector](https://discourse.julialang.org/t/a-sparse-matrix-cannot-be-indexed-by-a-svector/104265)

<div class="topic-metadata">

**Author:** [@pinkie.ljz](https://discourse.julialang.org/u/pinkie.ljz)\
**Replies:** 4\
**Last updated:** [September 26, 2023, 3:18pm UTC](https://discourse.julialang.org/t/a-sparse-matrix-cannot-be-indexed-by-a-svector/104265 "2023-09-26T15:18:04Z")

</div>

As indicated by the topic, I intend to replace some small matrices with the StaticArrays but the global sparse matrix created by SparseArrays.jl cannot be indexed by a SVector. A simple example is given as follows. usi…

---

## [Should we enable storage of function outputs in BenchmarkTools?](https://discourse.julialang.org/t/should-we-enable-storage-of-function-outputs-in-benchmarktools/103997)

<div class="topic-metadata">

**Author:** [@gdalle](https://discourse.julialang.org/u/gdalle)\
**Replies:** 13\
**Last updated:** [September 26, 2023, 3:01pm UTC](https://discourse.julialang.org/t/should-we-enable-storage-of-function-outputs-in-benchmarktools/103997 "2023-09-26T15:01:11Z")

</div>

Currently doing some maintenance on BenchmarkTools.jl before the upcoming 2.0 release (I’m aiming for October), and I stumbled upon a PR I’m unsure about. The author @AlexanderNenninger wants to record the values return…

---

## [Flux new explicit API not work but old implicit API works for a simple RNN](https://discourse.julialang.org/t/flux-new-explicit-api-not-work-but-old-implicit-api-works-for-a-simple-rnn/104262)

<div class="topic-metadata">

**Author:** [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Replies:** 0\
**Last updated:** [September 26, 2023, 1:36pm UTC](https://discourse.julialang.org/t/flux-new-explicit-api-not-work-but-old-implicit-api-works-for-a-simple-rnn/104262 "2023-09-26T13:36:37Z")

</div>

I am trying to reproduce the tutorial A Basic RNN using Flux.jl v0.14.6. Using the old Flux API as in the tutorial, the model can be successfully trained. The code is using Flux num\_samples = 1000 num\_epochs = 50 func…

---

## [CSV.read seems to expect at least 2 columns](https://discourse.julialang.org/t/csv-read-seems-to-expect-at-least-2-columns/104249)

<div class="topic-metadata">

**Author:** [@Axze-rgb](https://discourse.julialang.org/u/Axze-rgb)\
**Replies:** 12\
**Last updated:** [September 26, 2023, 10:39am UTC](https://discourse.julialang.org/t/csv-read-seems-to-expect-at-least-2-columns/104249 "2023-09-26T10:39:43Z")

</div>

Hello, I am using CSV.read to load a single column dataframe. Here is the command: df\_MQBZ=CSV.read(“MQBZ.hist”, DataFrame, header=false) That works but here is the result \> Column1 Column2 Missing String15 1 mis…

---

## [How to plot benchmarks](https://discourse.julialang.org/t/how-to-plot-benchmarks/104243)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 7\
**Last updated:** [September 26, 2023, 10:11am UTC](https://discourse.julialang.org/t/how-to-plot-benchmarks/104243 "2023-09-26T10:11:24Z")

</div>

Hi all, I would like to plot some benchmarks, but its not clear to me what approach to take. As a simple example, suppose I have: using BenchmarkTools using DataFrames using Statistics SUITE = BenchmarkGroup() SUITE…

---

## [Makie's hidden gems](https://discourse.julialang.org/t/makies-hidden-gems/104251)

<div class="topic-metadata">

**Author:** [@vvbond](https://discourse.julialang.org/u/vvbond)\
**Replies:** 0\
**Last updated:** [September 26, 2023, 9:59am UTC](https://discourse.julialang.org/t/makies-hidden-gems/104251 "2023-09-26T09:59:31Z")

</div>

I just came across this pattern of overloading Makielayout.get\_ticks() for a custom axis . Such an elegant example of use of Julia’s multiple dispatch for visualization of a bespoke axis type! The automatic support of th…

---

## [Need help understanding the allocations](https://discourse.julialang.org/t/need-help-understanding-the-allocations/104225)

<div class="topic-metadata">

**Author:** [@navdeeprana](https://discourse.julialang.org/u/navdeeprana)\
**Replies:** 8\
**Last updated:** [September 26, 2023, 9:15am UTC](https://discourse.julialang.org/t/need-help-understanding-the-allocations/104225 "2023-09-26T09:15:25Z")

</div>

Consider the following code using BenchmarkTools using Random using QuadGK f(p, xm, x) = -x^2 / ((p\[1\] - xm\[1\]\*x)^2 + (p\[2\] - xm\[2\]\*x)^2) g(p, xm, x) = -x^2 / ((p\[1\] - xm\[1\])^2 + (p\[2\] - xm\[2\])^2) integralf(p, xm) = qu…

---

## [Issues with Interactive Visualization in Agents.jl](https://discourse.julialang.org/t/issues-with-interactive-visualization-in-agents-jl/103640)

<div class="topic-metadata">

**Author:** [@daler6](https://discourse.julialang.org/u/daler6)\
**Replies:** 2\
**Last updated:** [September 26, 2023, 9:03am UTC](https://discourse.julialang.org/t/issues-with-interactive-visualization-in-agents-jl/103640 "2023-09-26T09:03:43Z")

</div>

schellingagentsjl5.jl (6.3 KB) The attached file contains my modified version of the code for the Schelling model, which I am running using the latest versions of VS Code, Julia, Agents.jl, and the other packages noted …

---

## [Sequence of JuMP problems -- reduce memory usage](https://discourse.julialang.org/t/sequence-of-jump-problems-reduce-memory-usage/103797)

<div class="topic-metadata">

**Author:** [@gmantegazza](https://discourse.julialang.org/u/gmantegazza)\
**Replies:** 9\
**Last updated:** [September 26, 2023, 8:27am UTC](https://discourse.julialang.org/t/sequence-of-jump-problems-reduce-memory-usage/103797 "2023-09-26T08:27:03Z")

</div>

Hello everyone, Thanks for existing! I have a problem withe memory usage when solving a sequence of JuMP problems. The structure of my code is the following. using JuMP using Gurobi function Opt(ID,Ind\_availL) Rou…

---

## [How to continue for loop even if model is infeasible](https://discourse.julialang.org/t/how-to-continue-for-loop-even-if-model-is-infeasible/104219)

<div class="topic-metadata">

**Author:** [@cdomenig](https://discourse.julialang.org/u/cdomenig)\
**Replies:** 3\
**Last updated:** [September 26, 2023, 8:11am UTC](https://discourse.julialang.org/t/how-to-continue-for-loop-even-if-model-is-infeasible/104219 "2023-09-26T08:11:24Z")

</div>

Hi everybody, I am currently running a MILP model in a for loop, where I am trying out around 800 different parameter combinations (a kind of sensivity analysis). Sometimes the model doesn’t find a feasible solutions (t…

---

## [GenieBuilder unable to install package](https://discourse.julialang.org/t/geniebuilder-unable-to-install-package/104123)

<div class="topic-metadata">

**Author:** [@vtomar](https://discourse.julialang.org/u/vtomar)\
**Replies:** 4\
**Last updated:** [September 26, 2023, 7:38am UTC](https://discourse.julialang.org/t/geniebuilder-unable-to-install-package/104123 "2023-09-26T07:38:08Z")

</div>

I get the following error: Pkg.add(url = “GitHub - GenieFramework/GenieBuilder.jl”) Cloning git-repo https://github.com/GenieFramework/GenieBuilder.jl.git Updating git-repo https://github.com/GenieFramework/GenieBuil…

---

## [Julia Plots circular marker with no fill (transparent inside)](https://discourse.julialang.org/t/julia-plots-circular-marker-with-no-fill-transparent-inside/104246)

<div class="topic-metadata">

**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 3\
**Last updated:** [September 26, 2023, 7:12am UTC](https://discourse.julialang.org/t/julia-plots-circular-marker-with-no-fill-transparent-inside/104246 "2023-09-26T07:12:27Z")

</div>

Hi, I’d like to make a circular marker without an interior color. I tried several things including this but didn’t work yet. julia\> using Plots julia\> a, b = \[1\], \[1\] (\[1\], \[1\]) julia\> scatter(a, b; markeralpha=0, m…

---

## [Cannot push Git commits by LibGit2](https://discourse.julialang.org/t/cannot-push-git-commits-by-libgit2/104076)

<div class="topic-metadata">

**Author:** [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Replies:** 7\
**Last updated:** [September 25, 2023, 4:29am UTC](https://discourse.julialang.org/t/cannot-push-git-commits-by-libgit2/104076 "2023-09-25T04:29:23Z")

</div>

I am trying to write a script that commits changes in files and pushes them to the upstream using LibGit2, but push() is not working. I am able to create a LibGit2.GitRepo, add changes to it, and commit the changes by r…

---

## [How does the Octeract engine compare to Alpine?](https://discourse.julialang.org/t/how-does-the-octeract-engine-compare-to-alpine/104231)

<div class="topic-metadata">

**Author:** [@Tarny\_GG\_Channie](https://discourse.julialang.org/u/Tarny_GG_Channie)\
**Replies:** 3\
**Last updated:** [September 26, 2023, 5:19am UTC](https://discourse.julialang.org/t/how-does-the-octeract-engine-compare-to-alpine/104231 "2023-09-26T05:19:14Z")

</div>

The octeract engine solved 100% of the Mittelmann MINLP benchmark. It is a commercial software. We have a free MINLP solver called Alpine. How do they compare? As a side note, why doesn’t JuMP list octeract as a com…

---

## [HiGHS Error: No invertible representation for getDualRay](https://discourse.julialang.org/t/highs-error-no-invertible-representation-for-getdualray/101372)

<div class="topic-metadata">

**Author:** [@Stuart\_Rogers](https://discourse.julialang.org/u/Stuart_Rogers)\
**Replies:** 16\
**Last updated:** [September 26, 2023, 2:48am UTC](https://discourse.julialang.org/t/highs-error-no-invertible-representation-for-getdualray/101372 "2023-09-26T02:48:57Z")

</div>

I get an error when I try to solve a feasibility problem in JuMP using HiGHS. I use Julia v1.9.1 with the Julia packages JuMP v1.12.0 and HiGHS v1.5.2. $ julia JuMP\_solve.jl Running HiGHS 1.5.3 \[date: 1970-01-01, git ha…

---

## [Exploring Quadratic forms with Julia](https://discourse.julialang.org/t/exploring-quadratic-forms-with-julia/104138)

<div class="topic-metadata">

**Author:** [@VinodV](https://discourse.julialang.org/u/VinodV)\
**Replies:** 11\
**Last updated:** [September 25, 2023, 11:20pm UTC](https://discourse.julialang.org/t/exploring-quadratic-forms-with-julia/104138 "2023-09-25T23:20:57Z")

</div>

Hi friends, I have published a blog post on Exploring Quadratic forms with Julia Just tried to make my understanding on Quadratic forms clearer using Julia. Please give your feedback on improvements/efficient code etc…

---

## [What visualisation library for cloth/physics sim](https://discourse.julialang.org/t/what-visualisation-library-for-cloth-physics-sim/104183)

<div class="topic-metadata">

**Author:** [@ollie\_d](https://discourse.julialang.org/u/ollie_d)\
**Replies:** 2\
**Last updated:** [September 25, 2023, 9:59pm UTC](https://discourse.julialang.org/t/what-visualisation-library-for-cloth-physics-sim/104183 "2023-09-25T21:59:40Z")

</div>

Sorry for the basic question. I want to make a cloth sim in 2d and then 3d and was wondering which package I should be using to display points and lines? Do i just use plots or is there something more suitable? thanks

---

## [Cthulhu and setindex!](https://discourse.julialang.org/t/cthulhu-and-setindex/104238)

<div class="topic-metadata">

**Author:** [@Salmon](https://discourse.julialang.org/u/Salmon)\
**Replies:** 2\
**Last updated:** [September 25, 2023, 7:18pm UTC](https://discourse.julialang.org/t/cthulhu-and-setindex/104238 "2023-09-25T19:18:54Z")

</div>

Hi everyone, for today a very simple question: why does Cthulhu seemingly shows this question is so basic that I feel like I must be missing something. julia\> function overwrite!(arr) arr\[1\] = zero(eltype(a…

---

## [Drawing a tubular path with Meshes.jl (blog post)](https://discourse.julialang.org/t/drawing-a-tubular-path-with-meshes-jl-blog-post/104203)

<div class="topic-metadata">

**Author:** [@\_stla](https://discourse.julialang.org/u/_stla)\
**Replies:** 10\
**Last updated:** [September 25, 2023, 6:45pm UTC](https://discourse.julialang.org/t/drawing-a-tubular-path-with-meshes-jl-blog-post/104203 "2023-09-25T18:45:10Z")

</div>

Hello, Follow the link to my blog.

---

## [Using random\_agent with a condition](https://discourse.julialang.org/t/using-random-agent-with-a-condition/104229)

<div class="topic-metadata">

**Author:** [@daler6](https://discourse.julialang.org/u/daler6)\
**Replies:** 2\
**Last updated:** [September 25, 2023, 6:31pm UTC](https://discourse.julialang.org/t/using-random-agent-with-a-condition/104229 "2023-09-25T18:31:59Z")

</div>

I am working on reproducing the Zero Information trader in Julia using Agents.jl. My agents include a field named :traded, which is of type Bool and is initialized to false for all agents. This is changed to true once an…

---

## [MATLAB/Simulink model simulation and modeling with s-functions and variable-step solver](https://discourse.julialang.org/t/matlab-simulink-model-simulation-and-modeling-with-s-functions-and-variable-step-solver/104220)

<div class="topic-metadata">

**Author:** [@alparg-mv](https://discourse.julialang.org/u/alparg-mv)\
**Replies:** 19\
**Last updated:** [September 25, 2023, 5:25pm UTC](https://discourse.julialang.org/t/matlab-simulink-model-simulation-and-modeling-with-s-functions-and-variable-step-solver/104220 "2023-09-25T17:25:44Z")

</div>

As a 10+ year old company working on HVAC system modeling on MATLAB/Simulink, we would like to transition to Julia for faster simulation and modeling of our Simulink model, where we also plan to accelerate the Simulation…

---

## [Display NTuples with more than one element as NTuples rather than Tuples?](https://discourse.julialang.org/t/display-ntuples-with-more-than-one-element-as-ntuples-rather-than-tuples/104143)

<div class="topic-metadata">

**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 4\
**Last updated:** [September 25, 2023, 4:49pm UTC](https://discourse.julialang.org/t/display-ntuples-with-more-than-one-element-as-ntuples-rather-than-tuples/104143 "2023-09-25T16:49:38Z")

</div>

This example is somewhat specific to making displayed types more legible, although this might help more generally. Currently, we have julia\> Tuple{Int, Int, Int} Tuple{Int64, Int64, Int64} julia\> Tuple{Int, Int, Int, …

---

## [Gradient accumulation using chainrulecore](https://discourse.julialang.org/t/gradient-accumulation-using-chainrulecore/104208)

<div class="topic-metadata">

**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 1\
**Last updated:** [September 25, 2023, 2:20pm UTC](https://discourse.julialang.org/t/gradient-accumulation-using-chainrulecore/104208 "2023-09-25T14:20:15Z")

</div>

Hi, I am using chainrulecore and zygote and rrule to define my accumulation derivation formulation. the derivative of my function is ∑\_(i=1)^n▒〖w^t da/dr u〗 in order to solve this i have defined below code. Note that…

---

## [How to predict new value corresponding to a new initial condition when using NeuralPDE](https://discourse.julialang.org/t/how-to-predict-new-value-corresponding-to-a-new-initial-condition-when-using-neuralpde/101224)

<div class="topic-metadata">

**Author:** [@Ethan\_Tran](https://discourse.julialang.org/u/Ethan_Tran)\
**Replies:** 1\
**Last updated:** [September 25, 2023, 1:42pm UTC](https://discourse.julialang.org/t/how-to-predict-new-value-corresponding-to-a-new-initial-condition-when-using-neuralpde/101224 "2023-09-25T13:42:19Z")

</div>

After using NeuralPDE to solve the ODEs system, I got the prediction for a specific system as a result of the training process by using the code in the tutorial below: ts = 0.0:0.01:10.0 minimizers\_ = \[res.u.depvar\[sym\_…

---

## [How to serialize data to, and deserialize from, postgres?](https://discourse.julialang.org/t/how-to-serialize-data-to-and-deserialize-from-postgres/103803)

<div class="topic-metadata">

**Author:** [@John\_Boik](https://discourse.julialang.org/u/John_Boik)\
**Replies:** 9\
**Last updated:** [September 25, 2023, 1:29pm UTC](https://discourse.julialang.org/t/how-to-serialize-data-to-and-deserialize-from-postgres/103803 "2023-09-25T13:29:18Z")

</div>

I would like to store some Julia data in a PostgreSQL bytea column and then query the database and convert the result back to its original form. I can store the data, but can’t seem to convert the query response correctl…

[Previous page](https://discourse.julialang.org/latest.md?page=588)

[Next page](https://discourse.julialang.org/latest.md?page=590)