# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1407

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

**Page:** 1408

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## [Adaptive step-size algorithm for stiff SDE solvers in StochasticDiffEq.jl](https://discourse.julialang.org/t/adaptive-step-size-algorithm-for-stiff-sde-solvers-in-stochasticdiffeq-jl/59785)

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**Author:** [@alvestad10](https://discourse.julialang.org/u/alvestad10)\
**Replies:** 2\
**Last updated:** [April 29, 2021, 1:57pm UTC](https://discourse.julialang.org/t/adaptive-step-size-algorithm-for-stiff-sde-solvers-in-stochasticdiffeq-jl/59785 "2021-04-29T13:57:56Z")

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Could someone point me in the direction of where to find info on how the time-stepping method for stiff SDE solvers is implemented? I am mainly interested in how the ImplicitEM solver does the adaptive stepsize control, …

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## [HTTP.jl IOError: stream is closed or unusable](https://discourse.julialang.org/t/http-jl-ioerror-stream-is-closed-or-unusable/31320)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 14\
**Last updated:** [April 29, 2021, 1:56pm UTC](https://discourse.julialang.org/t/http-jl-ioerror-stream-is-closed-or-unusable/31320 "2021-04-29T13:56:28Z")

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Hi all- I am trying to communicate with a Julia websocket server via Java and I encounter an error stating: IOError: stream is closed or unusable The server receives the message but Java never receives the response, p…

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## [PackageCompiler Bundle artifact](https://discourse.julialang.org/t/packagecompiler-bundle-artifact/60248)

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**Author:** [@spatJul](https://discourse.julialang.org/u/spatJul)\
**Replies:** 0\
**Last updated:** [April 29, 2021, 1:52pm UTC](https://discourse.julialang.org/t/packagecompiler-bundle-artifact/60248 "2021-04-29T13:52:15Z")

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Trying to create a package using create\_app(…) Getting this error Stacktrace: \[1\] uv\_error at .\\libuv.jl:97 \[inlined\] \[2\] open(::String, ::UInt16, ::UInt64) at .\\filesystem.jl:87 \[3\] sendfile(::String, ::String) at …

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## [Accessing a array type from a struct without declaring a new array](https://discourse.julialang.org/t/accessing-a-array-type-from-a-struct-without-declaring-a-new-array/60234)

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**Author:** [@Josa9321](https://discourse.julialang.org/u/Josa9321)\
**Replies:** 4\
**Last updated:** [April 29, 2021, 1:28pm UTC](https://discourse.julialang.org/t/accessing-a-array-type-from-a-struct-without-declaring-a-new-array/60234 "2021-04-29T13:28:48Z")

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I have a function that needs to access a matrix from a struct, but every time the function does this inside this loop, it’s like it creates a new matrix m = foo.bar, or at least the time to run and the allocation necess…

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## [Using NLopt through GalacticOptim](https://discourse.julialang.org/t/using-nlopt-through-galacticoptim/60244)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 0\
**Last updated:** [April 29, 2021, 1:27pm UTC](https://discourse.julialang.org/t/using-nlopt-through-galacticoptim/60244 "2021-04-29T13:27:11Z")

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I’m trying to use NLopt though GalacticOptim, but can’t get it work. What am I doing wrong below? using NLopt using GalacticOptim # rosenbrock function f(x; a=1, b=100) (a - x\[1\])^2 + b\*(x\[2\] - x\[1\]^2)^2 end # GO …

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## [Dependencies failed but may be precompilable after restarting julia | What are those question marks?](https://discourse.julialang.org/t/dependencies-failed-but-may-be-precompilable-after-restarting-julia-what-are-those-question-marks/60236)

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**Author:** [@meck](https://discourse.julialang.org/u/meck)\
**Replies:** 6\
**Last updated:** [April 29, 2021, 1:18pm UTC](https://discourse.julialang.org/t/dependencies-failed-but-may-be-precompilable-after-restarting-julia-what-are-those-question-marks/60236 "2021-04-29T13:18:52Z")

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I am trying to install a required package but it doenst work and I am getting a bunch of question marks. How do I solve this? Thank you. ERROR: LoadError: UndefVarError: AbstractPlotting not defined Stacktrace: \[1\] top…

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## [(CALL FOR PAPERS) PAW-ATM: Parallel Applications Workshop, Alternatives To MPI+](https://discourse.julialang.org/t/call-for-papers-paw-atm-parallel-applications-workshop-alternatives-to-mpi/60235)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [April 29, 2021, 12:23pm UTC](https://discourse.julialang.org/t/call-for-papers-paw-atm-parallel-applications-workshop-alternatives-to-mpi/60235 "2021-04-29T12:23:19Z")

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I saw an announcement for this conference. I am not involved, but it may be interesting to the Julia community. \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Call for Papers PAW-…

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## [Normalized nrow in a GroupedDataFrame](https://discourse.julialang.org/t/normalized-nrow-in-a-groupeddataframe/60226)

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**Author:** [@Storopoli](https://discourse.julialang.org/u/Storopoli)\
**Replies:** 4\
**Last updated:** [April 29, 2021, 12:22pm UTC](https://discourse.julialang.org/t/normalized-nrow-in-a-groupeddataframe/60226 "2021-04-29T12:22:59Z")

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What is the best way to do a “normalized” nrow in a gdf? using DataFrames using Chain df = DataFrame(id=1:6, name=\["Aaron Aardvark", "Belen Barboza", "春 陈", "Даниил Ду…

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## [Switching tasks mid-write()?](https://discourse.julialang.org/t/switching-tasks-mid-write/60232)

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**Author:** [@green.nsk](https://discourse.julialang.org/u/green.nsk)\
**Replies:** 4\
**Last updated:** [April 29, 2021, 12:19pm UTC](https://discourse.julialang.org/t/switching-tasks-mid-write/60232 "2021-04-29T12:19:48Z")

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I am running into a problem with my logging implementation, and I boiled it down to the following: function repro() @async write(stderr, "Foo", "\\n") @async write(stderr, "Bar", "\\n") nothing end re…

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## [Passing String parameters](https://discourse.julialang.org/t/passing-string-parameters/60211)

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**Author:** [@jrhut](https://discourse.julialang.org/u/jrhut)\
**Replies:** 8\
**Last updated:** [April 29, 2021, 12:18pm UTC](https://discourse.julialang.org/t/passing-string-parameters/60211 "2021-04-29T12:18:19Z")

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Hi there, I’m trying to pass a String to my function foo (s::A, n::N=2) where {A\<:Union{String,Vector{String}}, N \<: Number} I’m calling the function as so foo(“test”) and am receiving the error MethodError: Cannot co…

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## [DiffEq: SavingCallback, save befor and after other callback](https://discourse.julialang.org/t/diffeq-savingcallback-save-befor-and-after-other-callback/59263)

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**Author:** [@hexaeder](https://discourse.julialang.org/u/hexaeder)\
**Replies:** 7\
**Last updated:** [April 29, 2021, 11:21am UTC](https://discourse.julialang.org/t/diffeq-savingcallback-save-befor-and-after-other-callback/59263 "2021-04-29T11:21:03Z")

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I use a callback to alter the parameters p of my system. I also use a SavingCallback to save some function f(u,p) at every timestep. The parameter changing callback has the option save\_positions=(true,true) and saves th…

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## [How to plot with manually created legend entries?](https://discourse.julialang.org/t/how-to-plot-with-manually-created-legend-entries/60024)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 14\
**Last updated:** [April 29, 2021, 10:52am UTC](https://discourse.julialang.org/t/how-to-plot-with-manually-created-legend-entries/60024 "2021-04-29T10:52:04Z")

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I created my own legend entries following the docs, now I’d like to plot with them. MWE: using GLMakie legendentries = Dict("A" =\> LineElement(linestyle = nothing, linewidth = 0.3, color = :red), "…

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## [Multiple terminals open with Julia on macOS](https://discourse.julialang.org/t/multiple-terminals-open-with-julia-on-macos/50150)

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**Author:** [@bojohnson02](https://discourse.julialang.org/u/bojohnson02)\
**Replies:** 10\
**Last updated:** [April 29, 2021, 10:38am UTC](https://discourse.julialang.org/t/multiple-terminals-open-with-julia-on-macos/50150 "2021-04-29T10:38:21Z")

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I’ve installed the Julia .dmg file. Whenever I open the app, however, another normal terminal opens at the same time. Is this the expected behavior? If not, is there a way to tweak things so only the Julia terminal opens…

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## [Problem with StatsPlots](https://discourse.julialang.org/t/problem-with-statsplots/60155)

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**Author:** [@PCM](https://discourse.julialang.org/u/PCM)\
**Replies:** 9\
**Last updated:** [April 29, 2021, 10:35am UTC](https://discourse.julialang.org/t/problem-with-statsplots/60155 "2021-04-29T10:35:50Z")

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Hi, I am using Statsplots and Turing in a Jupyter notebook. I got the error message, below. M y configuration is (that’s what “\] status” says): Julia 1.6.1, IJulia v1.23.2, StatsPlots v0.14.20, Turing v0.15.16, Pluto v0.…

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## [How to remove one of type parameters in a method signature?](https://discourse.julialang.org/t/how-to-remove-one-of-type-parameters-in-a-method-signature/60070)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 2\
**Last updated:** [April 29, 2021, 10:29am UTC](https://discourse.julialang.org/t/how-to-remove-one-of-type-parameters-in-a-method-signature/60070 "2021-04-29T10:29:30Z")

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I have a bunch of method signatures like this: sig1 = Tuple{typeof(rrule), typeof(sum), AbstractArray{T, N} where N} where T\<:Number sig2 = Tuple{typeof(rrule), typeof(mean), AbstractArray{var"#s256", N} where {var"#s25…

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## [Pkg.add("PyPlot@2.9.0"); is not a valid package name](https://discourse.julialang.org/t/pkg-add-pyplot-2-9-0-is-not-a-valid-package-name/60228)

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**Author:** [@jcabrera](https://discourse.julialang.org/u/jcabrera)\
**Replies:** 2\
**Last updated:** [April 29, 2021, 9:08am UTC](https://discourse.julialang.org/t/pkg-add-pyplot-2-9-0-is-not-a-valid-package-name/60228 "2021-04-29T09:08:05Z")

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hi there, I’m using a command line to install packages. I have a problem when I want to fix the version. In the doc: https://pkgdocs.julialang.org/v1/managing-packages/ It is said that I can use @version, #branchname …

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## [Pluto on the web?](https://discourse.julialang.org/t/pluto-on-the-web/60022)

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**Author:** [@maajdl](https://discourse.julialang.org/u/maajdl)\
**Replies:** 9\
**Last updated:** [April 29, 2021, 8:50am UTC](https://discourse.julialang.org/t/pluto-on-the-web/60022 "2021-04-29T08:50:04Z")

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Hello My aim is to share Pluto notebooks with other people without any hassle for them. I mean, without asking them to install Julia and Pluto on their computer. Also without long explanations about opening an account…

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## [How to verify the convolution theorem in Julia?](https://discourse.julialang.org/t/how-to-verify-the-convolution-theorem-in-julia/60185)

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**Author:** [@Minimum-Pollution-96](https://discourse.julialang.org/u/Minimum-Pollution-96)\
**Replies:** 15\
**Last updated:** [April 29, 2021, 8:32am UTC](https://discourse.julialang.org/t/how-to-verify-the-convolution-theorem-in-julia/60185 "2021-04-29T08:32:30Z")

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I’ve trying to prove convolution theorem in Julia but without success. Say I have two function f1 = sin(30πt) & f2 = sin(10πt). Then, I have the following code fconv\_fda = ifft(fft(f1).\*fft(f2)) fconv\_tda = DSP.conv(f1,…

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## [Warning Error when Using DiffEquationSolver](https://discourse.julialang.org/t/warning-error-when-using-diffequationsolver/60218)

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**Author:** [@Peter-Jolly](https://discourse.julialang.org/u/Peter-Jolly)\
**Replies:** 4\
**Last updated:** [April 29, 2021, 8:23am UTC](https://discourse.julialang.org/t/warning-error-when-using-diffequationsolver/60218 "2021-04-29T08:23:31Z")

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I have been successfully solving a system of 123 ODE’s for the past few month using Julia. I have tried a number of solvers (see some commented out code below). The Tsit5 (fifth order Runge Kutta) generally does the job,…

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## [Differential equation with decimal exponent causing error](https://discourse.julialang.org/t/differential-equation-with-decimal-exponent-causing-error/59909)

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**Author:** [@Peter\_Uhl](https://discourse.julialang.org/u/Peter_Uhl)\
**Replies:** 9\
**Last updated:** [April 29, 2021, 7:45am UTC](https://discourse.julialang.org/t/differential-equation-with-decimal-exponent-causing-error/59909 "2021-04-29T07:45:06Z")

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I’m trying to solve an ode with a decimal exponent. The exponent sometimes gives a complex result which causes a domain error: LoadError: DomainError with -31175.19768524835: Exponentiation yielding a complex result re…

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## [Updating Packages](https://discourse.julialang.org/t/updating-packages/60222)

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**Author:** [@statspy](https://discourse.julialang.org/u/statspy)\
**Replies:** 2\
**Last updated:** [April 29, 2021, 6:38am UTC](https://discourse.julialang.org/t/updating-packages/60222 "2021-04-29T06:38:00Z")

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Why my DataFrame package does not update from ( 0.22.7 to 1.0) when I use: pkg\> update or pkg\>update DataFrames How do I update packages? Thanks

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## [NLopt with JuMP producing an error](https://discourse.julialang.org/t/nlopt-with-jump-producing-an-error/12063)

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**Author:** [@myroslav](https://discourse.julialang.org/u/myroslav)\
**Replies:** 1\
**Last updated:** [April 29, 2021, 6:25am UTC](https://discourse.julialang.org/t/nlopt-with-jump-producing-an-error/12063 "2021-04-29T06:25:16Z")

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Hi, I am trying to minimize a function subject to two boundary constraints and a linear inequality constraint. Here is a simplified version of what I am trying to do using JuMP using NLopt fopt2(bprime, pimortg) = bpri…

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## [No method matching promote\_shape](https://discourse.julialang.org/t/no-method-matching-promote-shape/60021)

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**Author:** [@zlq178](https://discourse.julialang.org/u/zlq178)\
**Replies:** 7\
**Last updated:** [April 29, 2021, 6:07am UTC](https://discourse.julialang.org/t/no-method-matching-promote-shape/60021 "2021-04-29T06:07:48Z")

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Here is a small example. using JuMP,Mosek,MosekTools u=rand(3,1) M\_SDP = Model(Mosek.Optimizer) #set\_silent(model) #set\_optimizer\_attribute(M\_SDP, "MSK\_IPAR\_LOG", 0) @variable(M\_SDP,buro\[1:3,1\]) # Z \>= 0, PSD @variable…

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## [Problem placing views into an array](https://discourse.julialang.org/t/problem-placing-views-into-an-array/60118)

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**Author:** [@Based](https://discourse.julialang.org/u/Based)\
**Replies:** 3\
**Last updated:** [April 29, 2021, 4:58am UTC](https://discourse.julialang.org/t/problem-placing-views-into-an-array/60118 "2021-04-29T04:58:57Z")

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When I add a view into an array, it creates a copy of it instead of creating a reference to the original view. Modifying the view does not modify the array it was added to. This is not the case when the array is not a vi…

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## [How to return a Symmetric matrix?](https://discourse.julialang.org/t/how-to-return-a-symmetric-matrix/60212)

<div class="topic-metadata">

**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 10\
**Last updated:** [April 29, 2021, 4:58am UTC](https://discourse.julialang.org/t/how-to-return-a-symmetric-matrix/60212 "2021-04-29T04:58:08Z")

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I’m constructing the Hessian of the Rosenbrock function. I want the return of h! to be of type Symmetric. using LinearAlgebra # for completeness function f(x; a=1, b=100) (a - x\[1\])^2 + b\*(x\[2\] - x\[1\]^2)^2 end fun…

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## [Event handler](https://discourse.julialang.org/t/event-handler/59937)

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**Author:** [@mschauer](https://discourse.julialang.org/u/mschauer)\
**Replies:** 11\
**Last updated:** [April 29, 2021, 12:46am UTC](https://discourse.julialang.org/t/event-handler/59937 "2021-04-29T00:46:44Z")

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I have a number of functions, all looking a bit like that: while true i = peel(Q) if i == 1 && mode = 1 a, b = dosomething1(a, b) elseif i == 2 b, c = dosomething2(b, c) elseif i == 3 …

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## [Did Julia code loading in distributed computing changed?](https://discourse.julialang.org/t/did-julia-code-loading-in-distributed-computing-changed/60202)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 6\
**Last updated:** [April 28, 2021, 9:47pm UTC](https://discourse.julialang.org/t/did-julia-code-loading-in-distributed-computing-changed/60202 "2021-04-28T21:47:46Z")

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Importing a module after addprocs() seems to try to load it an all workers. (@v1.6) pkg\> activate . Activating environment at \`C:\\Users\\blablabla...\\Project.toml\` (MyProject) pkg\> status Project BoseHubbardLyapu…

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## [Access infeasible optimization results ( GLPK with semicontinuous variable )](https://discourse.julialang.org/t/access-infeasible-optimization-results-glpk-with-semicontinuous-variable/59972)

<div class="topic-metadata">

**Author:** [@Runhong\_Huang](https://discourse.julialang.org/u/Runhong_Huang)\
**Replies:** 6\
**Last updated:** [April 28, 2021, 9:29pm UTC](https://discourse.julialang.org/t/access-infeasible-optimization-results-glpk-with-semicontinuous-variable/59972 "2021-04-28T21:29:03Z")

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Hi all, I have a question regarding accessing infeasible optimization results. For example, the following optimization does not have a feasible solution. However, despite the infeasibility, it is still able to give the…

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## [Ipopt Set Attribute](https://discourse.julialang.org/t/ipopt-set-attribute/59982)

<div class="topic-metadata">

**Author:** [@user1200](https://discourse.julialang.org/u/user1200)\
**Replies:** 4\
**Last updated:** [April 28, 2021, 9:28pm UTC](https://discourse.julialang.org/t/ipopt-set-attribute/59982 "2021-04-28T21:28:14Z")

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Hello I got little issue with model = Model(with\_optimizer(Ipopt.Optimizer, tol=1e-9)) #or set\_optimizer\_attribute(model, “constr\_viol\_tol”, 0) #throws this error when called optimize! It is a valid option, but …

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## [Dual{::ForwardDiff...} type error when JuMP tries autodiff User-defined Function](https://discourse.julialang.org/t/dual-forwarddiff-type-error-when-jump-tries-autodiff-user-defined-function/25639)

<div class="topic-metadata">

**Author:** [@KestutisMa](https://discourse.julialang.org/u/KestutisMa)\
**Replies:** 20\
**Last updated:** [April 28, 2021, 9:26pm UTC](https://discourse.julialang.org/t/dual-forwarddiff-type-error-when-jump-tries-autodiff-user-defined-function/25639 "2021-04-28T21:26:08Z")

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Hi, I am trying to optimize User-defined function with and I got this error: ERROR: LoadError: MethodError: no method matching Float64(::ForwardDiff.Dual{ForwardDiff.Tag{getfield(JuMP, Symbol("##84#86")){typeof(min\_f)},…

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