# Latest

**URL:** https://discourse.julialang.org/latest.md?page=250

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

**Page:** 251

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## [Dialog to select local directories with Genie.jl](https://discourse.julialang.org/t/dialog-to-select-local-directories-with-genie-jl/123996)

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**Author:** [@TheHedgehog2000](https://discourse.julialang.org/u/TheHedgehog2000)\
**Replies:** 5\
**Last updated:** [December 20, 2024, 7:00am UTC](https://discourse.julialang.org/t/dialog-to-select-local-directories-with-genie-jl/123996 "2024-12-20T07:00:50Z")

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Using Genie, I want to include a button in a web app that, once clicked, will trigger a dialog which allows a user to select folders containing data from their local computer to upload to the web app. I can do this using…

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## [Double yaxis using plotlyjs() as backend](https://discourse.julialang.org/t/double-yaxis-using-plotlyjs-as-backend/123978)

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**Author:** [@Stephen](https://discourse.julialang.org/u/Stephen)\
**Replies:** 3\
**Last updated:** [December 20, 2024, 5:30am UTC](https://discourse.julialang.org/t/double-yaxis-using-plotlyjs-as-backend/123978 "2024-12-20T05:30:38Z")

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Hello, there, I want plot δGDP and δM2 vs Year on left yaxis, whereas δGDP/δM2 vs Year on the right side Here is my code: anyon can help me with plot!? Thanks! using Plots plotlyjs() begin p = plot( Year, \[δM2…

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## [Automatic clipboard](https://discourse.julialang.org/t/automatic-clipboard/123949)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 11\
**Last updated:** [December 20, 2024, 1:26am UTC](https://discourse.julialang.org/t/automatic-clipboard/123949 "2024-12-20T01:26:52Z")

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I often want to paste output to Excel. So I’ve written this function toclip below. Is it possible to call this function automatically when a code block is executed via CTRL+Enter. toclip(x::String) …

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## [Versioninfo not defined in Main](https://discourse.julialang.org/t/versioninfo-not-defined-in-main/123969)

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**Author:** [@leespen1](https://discourse.julialang.org/u/leespen1)\
**Replies:** 4\
**Last updated:** [December 20, 2024, 12:22am UTC](https://discourse.julialang.org/t/versioninfo-not-defined-in-main/123969 "2024-12-20T00:22:05Z")

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I was debugging some issues I had using versioninfo() on an HPC, specifically that I would get the following error: ERROR: UndefVarError: \`versioninfo\` not defined in \`Main\` Suggestion: check for spelling errors or miss…

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## [\[ANN\] Jello.jl - Manufacturable geometry generation for topology optimization & generative design](https://discourse.julialang.org/t/ann-jello-jl-manufacturable-geometry-generation-for-topology-optimization-generative-design/106102)

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**Author:** [@pxshen](https://discourse.julialang.org/u/pxshen)\
**Replies:** 14\
**Last updated:** [December 19, 2024, 10:08pm UTC](https://discourse.julialang.org/t/ann-jello-jl-manufacturable-geometry-generation-for-topology-optimization-generative-design/106102 "2024-12-19T22:08:38Z")

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Hello friends Jello.jl uses a Fourier domain algorithm for generating manufacturable geometry for topology optimization & generative inverse design. Will take couple days for merging into general registry. Thanks …

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## [Keyword argument tab completion](https://discourse.julialang.org/t/keyword-argument-tab-completion/124000)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 1\
**Last updated:** [December 19, 2024, 9:41pm UTC](https://discourse.julialang.org/t/keyword-argument-tab-completion/124000 "2024-12-19T21:41:31Z")

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Is it possible for the REPL or VSCode to autocomplete the name of keywords. For example, after typing range(0,10, len and hitting the Tab key, I’d like to see the compeletion of length=, before I manually type in a val…

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## [Proper way to ccall mutable types](https://discourse.julialang.org/t/proper-way-to-ccall-mutable-types/123998)

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**Author:** [@mattsignorelli](https://discourse.julialang.org/u/mattsignorelli)\
**Replies:** 0\
**Last updated:** [December 19, 2024, 8:53pm UTC](https://discourse.julialang.org/t/proper-way-to-ccall-mutable-types/123998 "2024-12-19T20:53:03Z")

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Suppose I have a type mutable struct MyCType a::Cint b::Ptr{Cdouble} end corresponding exactly to a struct in C. Then I call a C library which has functions like void modify\_struct(myctype \*a) which mutates a. I…

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## [Number of differential equation / degree of freedom](https://discourse.julialang.org/t/number-of-differential-equation-degree-of-freedom/123644)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 1\
**Last updated:** [December 19, 2024, 8:48pm UTC](https://discourse.julialang.org/t/number-of-differential-equation-degree-of-freedom/123644 "2024-12-19T20:48:36Z")

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Today I was working on a (ModelingToolkit) problem with a single degree of freedom. But formulating everything with a single differential equation (plus supporting simple equations) turns out somewhat complicated / ugly.…

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## [Getting rid of ForwardDiff.jacobian! allocations when using closures](https://discourse.julialang.org/t/getting-rid-of-forwarddiff-jacobian-allocations-when-using-closures/123939)

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**Author:** [@franckgaga](https://discourse.julialang.org/u/franckgaga)\
**Replies:** 6\
**Last updated:** [December 19, 2024, 7:30pm UTC](https://discourse.julialang.org/t/getting-rid-of-forwarddiff-jacobian-allocations-when-using-closures/123939 "2024-12-19T19:30:38Z")

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I’m trying to get rid of the memory allocations in jacobian!. For this, I need to pass a cfg argument with a pre-allocated JacobianConfig to the function. According to the doc, its constructor expects to receive the func…

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## [\[ANN\] Julog.jl - Prolog-style logic programming in Julia](https://discourse.julialang.org/t/ann-julog-jl-prolog-style-logic-programming-in-julia/35400)

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**Author:** [@Xuan](https://discourse.julialang.org/u/Xuan)\
**Replies:** 13\
**Last updated:** [December 19, 2024, 6:35pm UTC](https://discourse.julialang.org/t/ann-julog-jl-prolog-style-logic-programming-in-julia/35400 "2024-12-19T18:35:26Z")

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For anyone who’s wished they could do logic programming in Julia (but, like me, found miniKanren difficult to learn), I’m excited to announce Julog.jl, a package for Prolog-style logic programming in Julia! It just got a…

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## [Reverse-mode autodiff with Enzyme involving WignerSymbols](https://discourse.julialang.org/t/reverse-mode-autodiff-with-enzyme-involving-wignersymbols/123967)

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**Author:** [@dameka](https://discourse.julialang.org/u/dameka)\
**Replies:** 5\
**Last updated:** [December 19, 2024, 6:32pm UTC](https://discourse.julialang.org/t/reverse-mode-autodiff-with-enzyme-involving-wignersymbols/123967 "2024-12-19T18:32:53Z")

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One part of a function chain I’m differentiating with Enzyme involves Clebsch-Gordan coefficients generated by the WignerSymbols package. I’m able to differentiate a MWE function with Forward mode, but Reverse mode gives…

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## [JuMP design question](https://discourse.julialang.org/t/jump-design-question/123927)

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**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 7\
**Last updated:** [December 19, 2024, 6:03pm UTC](https://discourse.julialang.org/t/jump-design-question/123927 "2024-12-19T18:03:30Z")

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Hi, I am building a model which is made up of smaller models. The smaller model definition can be found here: JuMP: which solver should I use for my problem? For context, the model linked above is a heat pump h which c…

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## [How to dispatch like f(::AbstractArray{T1,N+1}, ::AbstractArray{T2,N})?](https://discourse.julialang.org/t/how-to-dispatch-like-f-abstractarray-t1-n-1-abstractarray-t2-n/123995)

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**Author:** [@marcsgil](https://discourse.julialang.org/u/marcsgil)\
**Replies:** 2\
**Last updated:** [December 19, 2024, 4:51pm UTC](https://discourse.julialang.org/t/how-to-dispatch-like-f-abstractarray-t1-n-1-abstractarray-t2-n/123995 "2024-12-19T16:51:50Z")

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Is it possible to dispatch on the difference between the dimensions of two arrays arguments? One can, for example, define f(::AbstractArray{T1,N}, ::AbstractArray{T2,N}) where {T1,T2,N} = ... Then, this method will be …

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## [Error when compiling gather and scatter operation under Reactant](https://discourse.julialang.org/t/error-when-compiling-gather-and-scatter-operation-under-reactant/123930)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 6\
**Last updated:** [December 19, 2024, 4:57pm UTC](https://discourse.julialang.org/t/error-when-compiling-gather-and-scatter-operation-under-reactant/123930 "2024-12-19T16:57:04Z")

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Hi All, I have started to experiment with Lux, Enzyme, and Reactant. In my applications, I frequently need a operation described as segmented\_sum or segmented\_mean, which can be computed using compositions of scatter a…

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## [Plots.jl precompile performance](https://discourse.julialang.org/t/plots-jl-precompile-performance/123979)

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**Author:** [@deszoeke](https://discourse.julialang.org/u/deszoeke)\
**Replies:** 4\
**Last updated:** [December 19, 2024, 4:56pm UTC](https://discourse.julialang.org/t/plots-jl-precompile-performance/123979 "2024-12-19T16:56:11Z")

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Is there a lightweight version or workflow for Plots.jl that doesn’t precompile all the backends and dependencies? Most users will only need to use a small subset of backends from one environment, or maybe ever. Could th…

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## [CSV.jl writing quoted strings](https://discourse.julialang.org/t/csv-jl-writing-quoted-strings/123989)

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**Author:** [@TimG](https://discourse.julialang.org/u/TimG)\
**Replies:** 14\
**Last updated:** [December 19, 2024, 4:06pm UTC](https://discourse.julialang.org/t/csv-jl-writing-quoted-strings/123989 "2024-12-19T16:06:37Z")

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I am wondering when CSV.write chooses to quote a field when writing a file. I know I can use quotestrings=true to force all strings to be quoted, but in my case that seems unnecessary and undesirable. I can read a CSV f…

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## [Testing show methods](https://discourse.julialang.org/t/testing-show-methods/123933)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 20\
**Last updated:** [December 19, 2024, 3:05pm UTC](https://discourse.julialang.org/t/testing-show-methods/123933 "2024-12-19T15:05:26Z")

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I have defined a simple function to test show methods. It works like this: julia\> struct A x::Int y::Float64 p::String v::Vector{Float64} end julia\> function Base.show…

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## [Type unstability with args](https://discourse.julialang.org/t/type-unstability-with-args/123987)

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**Author:** [@hbrochet](https://discourse.julialang.org/u/hbrochet)\
**Replies:** 3\
**Last updated:** [December 19, 2024, 1:17pm UTC](https://discourse.julialang.org/t/type-unstability-with-args/123987 "2024-12-19T13:17:24Z")

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Hello, I would like to make the following function type stable: function f(args…) t = Tuple(\[arg\] for arg in args) return t end f(1,2.0,“s”) a run from @code\_warntype gives me julia\> @code\_warntype f2(1,2.0,“s…

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## [Mooncake with ForwardDiff](https://discourse.julialang.org/t/mooncake-with-forwarddiff/123952)

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**Author:** [@c\_sell](https://discourse.julialang.org/u/c_sell)\
**Replies:** 4\
**Last updated:** [December 19, 2024, 11:37am UTC](https://discourse.julialang.org/t/mooncake-with-forwarddiff/123952 "2024-12-19T11:37:14Z")

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Hello, I would like to know if: It is possible to compute the Hessian using a Mooncake backward pass and a ForwardDiff forward pass? Or are there other efficient methods to compute the Hessian? I tried using Differen…

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## [Problem with readlines function in windows](https://discourse.julialang.org/t/problem-with-readlines-function-in-windows/123970)

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**Author:** [@marodriguezs](https://discourse.julialang.org/u/marodriguezs)\
**Replies:** 6\
**Last updated:** [December 19, 2024, 11:02am UTC](https://discourse.julialang.org/t/problem-with-readlines-function-in-windows/123970 "2024-12-19T11:02:08Z")

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hi everyone, readlines function does not finish with Ctrl+d. Tested with julia REPL called from CMD, powershell, Windows Terminal, and from an small program. No problem with linux. julia\> versioninfo() Julia Version 1.…

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## [Is there a specific reason why the const keyword cannot be used within the scope of a function?](https://discourse.julialang.org/t/is-there-a-specific-reason-why-the-const-keyword-cannot-be-used-within-the-scope-of-a-function/123986)

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**Author:** [@stefkuypers](https://discourse.julialang.org/u/stefkuypers)\
**Replies:** 4\
**Last updated:** [December 19, 2024, 10:52am UTC](https://discourse.julialang.org/t/is-there-a-specific-reason-why-the-const-keyword-cannot-be-used-within-the-scope-of-a-function/123986 "2024-12-19T10:52:01Z")

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I noticed that trying to use the const keyword in a local scope results in a compilation error. Is there a specific reason for this? I wanted to define an anonymous function in a local scope (see Creating an anonymous fu…

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## [How fast does a model has to be for NMPC](https://discourse.julialang.org/t/how-fast-does-a-model-has-to-be-for-nmpc/120694)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 64\
**Last updated:** [December 19, 2024, 8:13am UTC](https://discourse.julialang.org/t/how-fast-does-a-model-has-to-be-for-nmpc/120694 "2024-12-19T08:13:11Z")

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How many times faster than real-time does a model has to be to be feasible for using model predictive control? Assumptions: 20Hz update rate 5s required horizon controller with three scalar outputs Of course this dep…

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## [Testing Julia REPL in a libuv spawn call](https://discourse.julialang.org/t/testing-julia-repl-in-a-libuv-spawn-call/123980)

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**Author:** [@klafyvel](https://discourse.julialang.org/u/klafyvel)\
**Replies:** 0\
**Last updated:** [December 19, 2024, 6:40am UTC](https://discourse.julialang.org/t/testing-julia-repl-in-a-libuv-spawn-call/123980 "2024-12-19T06:40:18Z")

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Hi there, I might use a bit of help with Lua, libuv, and the Julia REPL (I initially posted on slack, but folk rightfully pointed that this is better suited here). For context, I am writing integration tests for neovim’s…

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## [PyCall problem](https://discourse.julialang.org/t/pycall-problem/123977)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 6\
**Last updated:** [December 19, 2024, 4:24am UTC](https://discourse.julialang.org/t/pycall-problem/123977 "2024-12-19T04:24:16Z")

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my julia version is 1.10.0, and my system is windows 10. julia\> using PyCall julia\> using JLD julia\> @pyimport sympy.physics.wigner as wigner ERROR: PyError (PyImport\_ImportModule The Python package sympy.physics.wi…

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## [Help debugging problem with Pluto notebook](https://discourse.julialang.org/t/help-debugging-problem-with-pluto-notebook/123848)

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**Author:** [@adannenberg](https://discourse.julialang.org/u/adannenberg)\
**Replies:** 10\
**Last updated:** [December 19, 2024, 2:58am UTC](https://discourse.julialang.org/t/help-debugging-problem-with-pluto-notebook/123848 "2024-12-19T02:58:11Z")

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Hi. I have a notebook that used to work without problems. I don’t know if my problems stem from my notebook or from a change in Pluto or the other loaded packages. Strangely, the notebook hangs when first launched at 1…

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## [Build combined model from individual jump models](https://discourse.julialang.org/t/build-combined-model-from-individual-jump-models/123975)

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**Author:** [@jacob-roth](https://discourse.julialang.org/u/jacob-roth)\
**Replies:** 2\
**Last updated:** [December 19, 2024, 2:32am UTC](https://discourse.julialang.org/t/build-combined-model-from-individual-jump-models/123975 "2024-12-19T02:32:10Z")

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Suppose I have a two stage problem where I expect the user to provide (1) a first-stage model written in JuMP and (2) a function to evaluate the recourse. If the user’s recourse function evaluates subproblems also writte…

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## [How to get constraints from one JuMP model and use them in another JuMP model](https://discourse.julialang.org/t/how-to-get-constraints-from-one-jump-model-and-use-them-in-another-jump-model/20729)

<div class="topic-metadata">

**Author:** [@Mahbubar06](https://discourse.julialang.org/u/Mahbubar06)\
**Replies:** 8\
**Last updated:** [December 19, 2024, 1:30am UTC](https://discourse.julialang.org/t/how-to-get-constraints-from-one-jump-model-and-use-them-in-another-jump-model/20729 "2024-12-19T01:30:53Z")

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Hello, I have two JuMP model like following: m1=Model(solver=ClpSolver()) @variable(m1, x\[1:3\]\>=0) @constraint(m1, sum(x\[i\] for i in 1:3)\>=0) @constraint(m1, sum(x\[i\] for i in \[1,3\])\>=0) @constraint(m1, sum(x\[i\] for i …

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## [Julia compiler v.s. Julia GPU compiler](https://discourse.julialang.org/t/julia-compiler-v-s-julia-gpu-compiler/123951)

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**Author:** [@huiyuxie](https://discourse.julialang.org/u/huiyuxie)\
**Replies:** 4\
**Last updated:** [December 19, 2024, 1:29am UTC](https://discourse.julialang.org/t/julia-compiler-v-s-julia-gpu-compiler/123951 "2024-12-19T01:29:10Z")

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I’m currently developing a package to provide CUDA.jl support for solving hyperbolic PDEs on GPUs. I recently completed some coarse timing tests on the core acceleration parts of the solvers using a script similar to thi…

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## [OutOfMemoryError in HomotopyContinuation](https://discourse.julialang.org/t/outofmemoryerror-in-homotopycontinuation/95105)

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**Author:** [@Ricardo\_Miranda\_Mart](https://discourse.julialang.org/u/Ricardo_Miranda_Mart)\
**Replies:** 1\
**Last updated:** [December 19, 2024, 1:28am UTC](https://discourse.julialang.org/t/outofmemoryerror-in-homotopycontinuation/95105 "2024-12-19T01:28:28Z")

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Hi all, I’m trying to use HomotopyContinuation.jl to find all of the solutions a polynomial system of equations with 14 polynomials in 14 variables. Each polynomial is sum of monomials of degree from 10 to 13 (like f1=…

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## [Formatting floating point values as fixed width for printing with "$(value)"?](https://discourse.julialang.org/t/formatting-floating-point-values-as-fixed-width-for-printing-with-value/123968)

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**Author:** [@world-peace](https://discourse.julialang.org/u/world-peace)\
**Replies:** 3\
**Last updated:** [December 19, 2024, 1:23am UTC](https://discourse.julialang.org/t/formatting-floating-point-values-as-fixed-width-for-printing-with-value/123968 "2024-12-19T01:23:37Z")

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I’m trying to add some logging to an existing codebase. I am trying to add some timing information to these logs. Logs are quite simple, they are just println statements wrapped by some functions. I would like to be a…

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