# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1047

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

**Page:** 1048

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## [Cannot take the CPU address of a CUDA.CuArray{Float32, 1, CUDA.Mem.DeviceBuffer} in LinearAlgebra matmul](https://discourse.julialang.org/t/cannot-take-the-cpu-address-of-a-cuda-cuarray-float32-1-cuda-mem-devicebuffer-in-linearalgebra-matmul/80666)

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**Author:** [@LarsWl](https://discourse.julialang.org/u/LarsWl)\
**Replies:** 0\
**Last updated:** [May 7, 2022, 12:53pm UTC](https://discourse.julialang.org/t/cannot-take-the-cpu-address-of-a-cuda-cuarray-float32-1-cuda-mem-devicebuffer-in-linearalgebra-matmul/80666 "2022-05-07T12:53:17Z")

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Have such function, that usually calculated correct. function predict\_train(model::Model, batch) (calculate\_hidden(model, batch, dropout\_active=true) .^ 3) |\> model.upper\_layer |\> (upper) -\> model.output\_laye…

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## [Does Searchlight ORM have relationships?](https://discourse.julialang.org/t/does-searchlight-orm-have-relationships/80660)

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**Author:** [@Xergon](https://discourse.julialang.org/u/Xergon)\
**Replies:** 1\
**Last updated:** [May 7, 2022, 12:23pm UTC](https://discourse.julialang.org/t/does-searchlight-orm-have-relationships/80660 "2022-05-07T12:23:27Z")

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Hey all, Does Searchlight have active support for relational databases? I know it has a Relationships module but the usage is not very clear. If so, can you explain a bit? I am very new to the genie ecosystem and my ex…

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## [Create vector with dependent values](https://discourse.julialang.org/t/create-vector-with-dependent-values/80611)

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**Author:** [@vamp](https://discourse.julialang.org/u/vamp)\
**Replies:** 4\
**Last updated:** [May 7, 2022, 12:16pm UTC](https://discourse.julialang.org/t/create-vector-with-dependent-values/80611 "2022-05-07T12:16:57Z")

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Hello, I am new to Julia and I have to create a vector which values are dependent. Let me put an example: If I have MyStruct(22, \[0, 0, 0\], 0) , the next values can be MyStruct(21, \[0, 0, 1\], 0) , MyStruct(21, \[0, 1, 0…

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## [Useful: How to check the parameters that can be used by a function](https://discourse.julialang.org/t/useful-how-to-check-the-parameters-that-can-be-used-by-a-function/80659)

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**Author:** [@dmolina](https://discourse.julialang.org/u/dmolina)\
**Replies:** 0\
**Last updated:** [May 7, 2022, 11:24am UTC](https://discourse.julialang.org/t/useful-how-to-check-the-parameters-that-can-be-used-by-a-function/80659 "2022-05-07T11:24:04Z")

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Sometimes I create functions that receive a function as parameter, but in Julia the type is Function without any information, so when the function pass as parameter is not right, the error message is not very informative…

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## [Working with \`LinearAlgebra.mul!\`](https://discourse.julialang.org/t/working-with-linearalgebra-mul/80649)

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**Author:** [@sinecera10](https://discourse.julialang.org/u/sinecera10)\
**Replies:** 12\
**Last updated:** [May 7, 2022, 11:42am UTC](https://discourse.julialang.org/t/working-with-linearalgebra-mul/80649 "2022-05-07T11:42:30Z")

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Reposting a reddit post here to solicit comments from the Julia community. I may have chanced upon a bug? According to reddit users No-Distribution4263 and Foura5 both foo! and bar! should result in an error. But the cas…

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## [Weave hangs when I tried it](https://discourse.julialang.org/t/weave-hangs-when-i-tried-it/38483)

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**Author:** [@Xing\_Shi\_Cai](https://discourse.julialang.org/u/Xing_Shi_Cai)\
**Replies:** 2\
**Last updated:** [May 7, 2022, 10:38am UTC](https://discourse.julialang.org/t/weave-hangs-when-i-tried-it/38483 "2022-05-07T10:38:35Z")

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I tried the following code from the document. (weave) pkg\> st Status \`~/Work/weave/Project.toml\` \[717857b8\] DSP v0.6.6 \[91a5bcdd\] Plots v1.2.0 \[44d3d7a6\] Weave v0.9.4 julia\> using Weave julia\> weave(joinpath(dir…

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## [Using Polynomials.jl with CUDA.jl](https://discourse.julialang.org/t/using-polynomials-jl-with-cuda-jl/80580)

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**Author:** [@GHRALIMA](https://discourse.julialang.org/u/GHRALIMA)\
**Replies:** 3\
**Last updated:** [May 7, 2022, 10:15am UTC](https://discourse.julialang.org/t/using-polynomials-jl-with-cuda-jl/80580 "2022-05-07T10:15:03Z")

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I’m on my very first trial with CUDA.jl, and I’m trying to use it together with Polynomials.jl to calculate the roots of thousands of polynomials with my NVidia GPU. However, when I try to create a polynomial using CuArr…

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## [The reasons why ABM is not a parameterized type in Agents.jl?](https://discourse.julialang.org/t/the-reasons-why-abm-is-not-a-parameterized-type-in-agents-jl/80538)

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**Author:** [@Atiyah](https://discourse.julialang.org/u/Atiyah)\
**Replies:** 4\
**Last updated:** [May 7, 2022, 5:39am UTC](https://discourse.julialang.org/t/the-reasons-why-abm-is-not-a-parameterized-type-in-agents-jl/80538 "2022-05-07T05:39:14Z")

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I am new to Julia and therefore my curiosity in some implementation details. In the package Agents.jl, the type constructor of Agents.AgentBasedModel is expecting a type as its first argument (specifically an AgentType \<…

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## [Optimizing over an integral that is computed with simulation](https://discourse.julialang.org/t/optimizing-over-an-integral-that-is-computed-with-simulation/80646)

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**Author:** [@samerb](https://discourse.julialang.org/u/samerb)\
**Replies:** 2\
**Last updated:** [May 7, 2022, 3:47am UTC](https://discourse.julialang.org/t/optimizing-over-an-integral-that-is-computed-with-simulation/80646 "2022-05-07T03:47:21Z")

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If g(x)\\equiv \\int h(\\tau) dF(\\tau) is a multi-dimensional integral which I’d need Monte Carlo integration to compute, is there a good way to optimize the function g(\\cdot)? Would standard optimization routines (from e.…

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## [Too much time when i solve MISOCP with Gurobi](https://discourse.julialang.org/t/too-much-time-when-i-solve-misocp-with-gurobi/80644)

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**Author:** [@mahon](https://discourse.julialang.org/u/mahon)\
**Replies:** 4\
**Last updated:** [May 7, 2022, 3:40am UTC](https://discourse.julialang.org/t/too-much-time-when-i-solve-misocp-with-gurobi/80644 "2022-05-07T03:40:22Z")

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this is my model julia\> model A JuMP Model Minimization problem with: Variables: 8915 Objective function type: AffExpr \`AffExpr\`-in-\`MathOptInterface.EqualTo{Float64}\`: 2716 constraints \`AffExpr\`-in-\`MathOptInterface.Gr…

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## [A question about write\_to\_file in JuMP](https://discourse.julialang.org/t/a-question-about-write-to-file-in-jump/80643)

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**Author:** [@mahon](https://discourse.julialang.org/u/mahon)\
**Replies:** 1\
**Last updated:** [May 7, 2022, 3:25am UTC](https://discourse.julialang.org/t/a-question-about-write-to-file-in-jump/80643 "2022-05-07T03:25:12Z")

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My model is a MISOCP model with Gurobi, if i want to solve it directly with Gurobi, how to code it? julia\> write\_to\_file(model, "model.lp") ERROR: MathOptInterface.UnsupportedConstraint{MathOptInterface.VectorAffineFunc…

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## [Branching solution accepted although it violates presently added lazy constraints](https://discourse.julialang.org/t/branching-solution-accepted-although-it-violates-presently-added-lazy-constraints/80622)

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**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 5\
**Last updated:** [May 7, 2022, 1:03am UTC](https://discourse.julialang.org/t/branching-solution-accepted-although-it-violates-presently-added-lazy-constraints/80622 "2022-05-07T01:03:15Z")

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I can not produce a MWE because the code is too big so I am going to describe. I have a JuMP model and Gurobi optimizer. I launch a callback where cb\_where is MIP\_SOL and all my variables are integer. On this callback, …

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## [How to reopen a shared library?](https://discourse.julialang.org/t/how-to-reopen-a-shared-library/80642)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 0\
**Last updated:** [May 7, 2022, 12:41am UTC](https://discourse.julialang.org/t/how-to-reopen-a-shared-library/80642 "2022-05-07T00:41:56Z")

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I’m using a shared library by ccall in my code, it works fine as long as the library does not change. However, if I’ve used the library in Julia REPL, then changed c source code and recompiled the library, the Julia REP…

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## [Calling struct fields with symbol or string](https://discourse.julialang.org/t/calling-struct-fields-with-symbol-or-string/80633)

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**Author:** [@stephans3](https://discourse.julialang.org/u/stephans3)\
**Replies:** 3\
**Last updated:** [May 7, 2022, 12:21am UTC](https://discourse.julialang.org/t/calling-struct-fields-with-symbol-or-string/80633 "2022-05-07T00:21:51Z")

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Hi all, I got to the problem how to call field names in a struct automatically with symbols or strings. This can be solved manually with if-else-constructions but is quite long and error-prone. Beside some related top…

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## [Why can't Enums be #undef?](https://discourse.julialang.org/t/why-cant-enums-be-undef/80635)

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**Author:** [@janneshb](https://discourse.julialang.org/u/janneshb)\
**Replies:** 8\
**Last updated:** [May 6, 2022, 11:14pm UTC](https://discourse.julialang.org/t/why-cant-enums-be-undef/80635 "2022-05-06T23:14:40Z")

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When trying to initialize Enum as #undef it instead goes into an invalid state by adopting an arbitrary integer. Consider the following example: julia\> @enum Fruit Apple Banana Peach julia\> struct Basket{T} …

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## [Need help in formatting bar plot in Makie](https://discourse.julialang.org/t/need-help-in-formatting-bar-plot-in-makie/80496)

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**Author:** [@EricChameroy](https://discourse.julialang.org/u/EricChameroy)\
**Replies:** 2\
**Last updated:** [May 6, 2022, 10:17pm UTC](https://discourse.julialang.org/t/need-help-in-formatting-bar-plot-in-makie/80496 "2022-05-06T22:17:18Z")

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I’m trying to recreate the following image using Makie and I’m having issues with some of the final formatting: So far, I managed to come up with the following: using CairoMakie age\_groups = \["0-12", "13-24", "25-3…

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## [Next portable Julia in VSCode](https://discourse.julialang.org/t/next-portable-julia-in-vscode/80626)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 11\
**Last updated:** [May 6, 2022, 9:40pm UTC](https://discourse.julialang.org/t/next-portable-julia-in-vscode/80626 "2022-05-06T21:40:45Z")

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https://github.com/PetrKryslUCSD/VSCode\_Julia\_portable The whole package consists of a couple of scripts that install Git and a working Julia and preconfigured VSCode. Everything is confined to a single folder (includin…

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## [DifferentialEquations: Sundials and LSODA report convergence failure, Julia solvers silently fail?](https://discourse.julialang.org/t/differentialequations-sundials-and-lsoda-report-convergence-failure-julia-solvers-silently-fail/80489)

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**Author:** [@qtoloza](https://discourse.julialang.org/u/qtoloza)\
**Replies:** 2\
**Last updated:** [May 6, 2022, 9:20pm UTC](https://discourse.julialang.org/t/differentialequations-sundials-and-lsoda-report-convergence-failure-julia-solvers-silently-fail/80489 "2022-05-06T21:20:14Z")

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Hi all! I have an ODE whose solution (mysteriously to me) fails to converge for a set of inputs. The real problem is that solve() does not throw an error and halt integration when I use a native Julia solver (I’ve tried…

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## [Julia lovers and developers](https://discourse.julialang.org/t/julia-lovers-and-developers/80637)

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**Author:** [@cwiese](https://discourse.julialang.org/u/cwiese)\
**Replies:** 1\
**Last updated:** [May 6, 2022, 8:12pm UTC](https://discourse.julialang.org/t/julia-lovers-and-developers/80637 "2022-05-06T20:12:42Z")

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100% remote - for skilled Julia Developers - please email resume cwiese “at” gmail.com Position #1: Portfolio Risk Assessment project - requires Julia and Python, with AWS skills - data wrangling pipelines to S3 - h…

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## [Python and/or Julia Software Engineer Needed](https://discourse.julialang.org/t/python-and-or-julia-software-engineer-needed/79835)

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**Author:** [@juliafanatics](https://discourse.julialang.org/u/juliafanatics)\
**Replies:** 2\
**Last updated:** [May 6, 2022, 8:05pm UTC](https://discourse.julialang.org/t/python-and-or-julia-software-engineer-needed/79835 "2022-05-06T20:05:37Z")

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Senior Python and/or Julia Software Engineer with strong SQL skills As the Senior Python/Julia Software Engineer, you will be responsible for designing and developing core software assets that perform data integration. …

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## [Improve performance of Bellman operator](https://discourse.julialang.org/t/improve-performance-of-bellman-operator/80624)

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**Author:** [@axel365](https://discourse.julialang.org/u/axel365)\
**Replies:** 7\
**Last updated:** [May 6, 2022, 8:05pm UTC](https://discourse.julialang.org/t/improve-performance-of-bellman-operator/80624 "2022-05-06T20:05:12Z")

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Hi there, I am creating a function for the Bellman operator, a common tool in economics and macroeconomics. The function takes an Array of dimension n where n is the number of state variables and iterates it one period,…

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## [Time Series sensitivity analysis for multiple outputs](https://discourse.julialang.org/t/time-series-sensitivity-analysis-for-multiple-outputs/80631)

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**Author:** [@xztt](https://discourse.julialang.org/u/xztt)\
**Replies:** 1\
**Last updated:** [May 6, 2022, 7:54pm UTC](https://discourse.julialang.org/t/time-series-sensitivity-analysis-for-multiple-outputs/80631 "2022-05-06T19:54:43Z")

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Hi, function circ\_local\_time(x) \_prob = remake(prob,u0=x\[1:3\],p=x\[4:end\]) sol = solve(\_prob,Tsit5(), reltol=1e-6, abstol=1e-6,saveat=savetime) sol\[LV.p\] end St = ForwardDiff.jacobian(circ\_local\_time,\[u0;p\])…

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## [Optimization of large ODE/DAE system](https://discourse.julialang.org/t/optimization-of-large-ode-dae-system/80557)

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**Author:** [@mzhenirovskyy](https://discourse.julialang.org/u/mzhenirovskyy)\
**Replies:** 8\
**Last updated:** [May 6, 2022, 7:11pm UTC](https://discourse.julialang.org/t/optimization-of-large-ode-dae-system/80557 "2022-05-06T19:11:44Z")

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Hi All, A big picture question about optimization of large ODE/DAE system. Suppose I have a big DAE system (number of equations ~ 100-200, number of parameters to optimize ~ 10-20) Julia has a bunch of optimization t…

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## [I want to make an hospital emergency department model in Julia](https://discourse.julialang.org/t/i-want-to-make-an-hospital-emergency-department-model-in-julia/80607)

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**Author:** [@Floyd\_Gartner](https://discourse.julialang.org/u/Floyd_Gartner)\
**Replies:** 1\
**Last updated:** [May 6, 2022, 6:31pm UTC](https://discourse.julialang.org/t/i-want-to-make-an-hospital-emergency-department-model-in-julia/80607 "2022-05-06T18:31:54Z")

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Hi everybody, I’m super new to Julia and still don’t know how to get started. I want to make a model that simulates an emergency department in a hospital. More specifically I want to show the patient assignment to free…

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## [Which parameter estimation technique should I learn?](https://discourse.julialang.org/t/which-parameter-estimation-technique-should-i-learn/80378)

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**Author:** [@BinaryBot](https://discourse.julialang.org/u/BinaryBot)\
**Replies:** 5\
**Last updated:** [May 6, 2022, 5:28pm UTC](https://discourse.julialang.org/t/which-parameter-estimation-technique-should-i-learn/80378 "2022-05-06T17:28:32Z")

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I would like to ask the Julia community which Parameter Estimation package should I learn/use for my following problem: I have defined a ODE that has over 20 fixed parameters and there is 4 I would like to optimise. I …

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## [Best Practices for Debugging DiffEqFlux Errors](https://discourse.julialang.org/t/best-practices-for-debugging-diffeqflux-errors/80618)

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**Author:** [@jbu](https://discourse.julialang.org/u/jbu)\
**Replies:** 1\
**Last updated:** [May 6, 2022, 4:26pm UTC](https://discourse.julialang.org/t/best-practices-for-debugging-diffeqflux-errors/80618 "2022-05-06T16:26:19Z")

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What are best practices for debugging when encountering errors with DiffEqFlux problems? I’m working on creating a differentiable ODE simulator with DiffEqFlux. It’s an amazing and powerful tool! However, debugging taki…

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## [Speed of power "^"](https://discourse.julialang.org/t/speed-of-power/80605)

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**Author:** [@zhubonan](https://discourse.julialang.org/u/zhubonan)\
**Replies:** 16\
**Last updated:** [May 6, 2022, 3:17pm UTC](https://discourse.julialang.org/t/speed-of-power/80605 "2022-05-06T15:17:26Z")

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I am writing a code that involves lots of use of “^” and profiling seems to suggest “^” is contributing a lot of the time. I have done the following test of the timing. Replacing “^” “\*” seems to give a massive speed up…

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## [Linear combinations of Zygote.Grads](https://discourse.julialang.org/t/linear-combinations-of-zygote-grads/80621)

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**Author:** [@5Pack](https://discourse.julialang.org/u/5Pack)\
**Replies:** 0\
**Last updated:** [May 6, 2022, 3:03pm UTC](https://discourse.julialang.org/t/linear-combinations-of-zygote-grads/80621 "2022-05-06T15:03:57Z")

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Here is a question I posted on Stack Overflow, but I thought it would be good to post it here also. Thank you in advance for your help! https://stackoverflow.com/questions/72143438/linear-combinations-of-zygote-grads

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## [Interpolation for multivariate function](https://discourse.julialang.org/t/interpolation-for-multivariate-function/80410)

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**Author:** [@axel365](https://discourse.julialang.org/u/axel365)\
**Replies:** 5\
**Last updated:** [May 6, 2022, 2:59pm UTC](https://discourse.julialang.org/t/interpolation-for-multivariate-function/80410 "2022-05-06T14:59:20Z")

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Hi everybody, I have a sample of points for a multivariate function that I would like to approximate with interpolation, where all arguments are on a grid. I would like to get a value for that function for other (interi…

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## [Two stage stochastic](https://discourse.julialang.org/t/two-stage-stochastic/78767)

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**Author:** [@HosseinF](https://discourse.julialang.org/u/HosseinF)\
**Replies:** 8\
**Last updated:** [May 6, 2022, 1:59pm UTC](https://discourse.julialang.org/t/two-stage-stochastic/78767 "2022-05-06T13:59:42Z")

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Hello every one. I am new to Julia. I want to extract the second stage decisional variables but it does not work. Does every one know that what is the problem?

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