# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1763

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

**Page:** 1764

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## [ERROR: Unable to automatically install 'OpenBLAS'](https://discourse.julialang.org/t/error-unable-to-automatically-install-openblas/38298)

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**Author:** [@Massimiliano\_Comin](https://discourse.julialang.org/u/Massimiliano_Comin)\
**Replies:** 0\
**Last updated:** [April 27, 2020, 12:36pm UTC](https://discourse.julialang.org/t/error-unable-to-automatically-install-openblas/38298 "2020-04-27T12:36:49Z")

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Hello ! I moved to Julia v1.4.1, and I get the following error when trying to re-install e.g. Arpack: ERROR: Unable to automatically install 'OpenBLAS' from '/home/mcomin/.julia/packages/OpenBLAS\_jll/DJCMI/Artifacts.to…

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## [Calculation of a Jacobian of a set of complex functions in Julia](https://discourse.julialang.org/t/calculation-of-a-jacobian-of-a-set-of-complex-functions-in-julia/38356)

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**Author:** [@fermion4](https://discourse.julialang.org/u/fermion4)\
**Replies:** 0\
**Last updated:** [April 28, 2020, 8:05am UTC](https://discourse.julialang.org/t/calculation-of-a-jacobian-of-a-set-of-complex-functions-in-julia/38356 "2020-04-28T08:05:50Z")

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I want to calculate the numerical Jacobian of complex functions using the Julia ForwardDiff package. using ForwardDiff f(θ,i,u) = \[1im \*i \* exp(-1im \* θ), 1im \* u \* exp(-1im \* θ)\] # Complex Current and Voltage z = \[1,…

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## [Why calculating gradients from Params is different than doing it directly?](https://discourse.julialang.org/t/why-calculating-gradients-from-params-is-different-than-doing-it-directly/38295)

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**Author:** [@AdamR](https://discourse.julialang.org/u/AdamR)\
**Replies:** 5\
**Last updated:** [April 28, 2020, 8:05am UTC](https://discourse.julialang.org/t/why-calculating-gradients-from-params-is-different-than-doing-it-directly/38295 "2020-04-28T08:05:20Z")

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I’ve encoutered a case when calculating gradients with two methods yield different results. Here is an excerpt from my code, excluding the actual loss function. julia\> x, y=get\_batch(4) (\[("1c944ea1a3ae18a8df9f411d3c6…

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## [Performance of collecting a zip where one argument to zip has eltype == Union{Nothing, Int}](https://discourse.julialang.org/t/performance-of-collecting-a-zip-where-one-argument-to-zip-has-eltype-union-nothing-int/38310)

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**Author:** [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Replies:** 4\
**Last updated:** [April 28, 2020, 4:33am UTC](https://discourse.julialang.org/t/performance-of-collecting-a-zip-where-one-argument-to-zip-has-eltype-union-nothing-int/38310 "2020-04-28T04:33:47Z")

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I ran into an interesting performance issue when collecting a zip. Before you say “don’t collect!”, the next step is to feed the collected array into sort, which throws a method error if you feed it a zip iterator. The i…

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## [Passing along data from one time step to the next using DifferentialEquations.jl](https://discourse.julialang.org/t/passing-along-data-from-one-time-step-to-the-next-using-differentialequations-jl/38335)

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**Author:** [@bielim](https://discourse.julialang.org/u/bielim)\
**Replies:** 5\
**Last updated:** [April 28, 2020, 2:28am UTC](https://discourse.julialang.org/t/passing-along-data-from-one-time-step-to-the-next-using-differentialequations-jl/38335 "2020-04-28T02:28:20Z")

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I am using DifferentialEquations.jl to solve an ODE of the form \\frac{d\\boldsymbol{M}}{dt} = \\boldsymbol{f}(\\boldsymbol{M}), where \\boldsymbol{M} = \[M\_1, ..., M\_k\]^T, and \\boldsymbol{f} = \[f\_1(\\boldsymbol{M}), ..., f\_k(\\…

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## [Get latest versions of dependencies as of a specific date?](https://discourse.julialang.org/t/get-latest-versions-of-dependencies-as-of-a-specific-date/38326)

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**Author:** [@crbinz](https://discourse.julialang.org/u/crbinz)\
**Replies:** 2\
**Last updated:** [April 28, 2020, 2:25am UTC](https://discourse.julialang.org/t/get-latest-versions-of-dependencies-as-of-a-specific-date/38326 "2020-04-28T02:25:20Z")

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I know this is a long-shot, but I thought I’d ask anyway. I’m currently trying to figure out how my tests broke, and because I am probably not as rigorous about setting version bounds on dependencies (lesson learned…), I…

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## ["Domain-Specific Languages" in Julia](https://discourse.julialang.org/t/domain-specific-languages-in-julia/13182)

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**Author:** [@jandehaan](https://discourse.julialang.org/u/jandehaan)\
**Replies:** 24\
**Last updated:** [April 28, 2020, 12:40am UTC](https://discourse.julialang.org/t/domain-specific-languages-in-julia/13182 "2020-04-28T00:40:12Z")

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When I read or hear about domain-specific languages in Julia I tend to cringe a little. In most cases it is not about a language, but rather an API. The difference? A DSL uses a syntax appropriate for its domain. An AP…

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## [A small package to run string as shell command](https://discourse.julialang.org/t/a-small-package-to-run-string-as-shell-command/6163)

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**Author:** [@innerlee](https://discourse.julialang.org/u/innerlee)\
**Replies:** 8\
**Last updated:** [April 28, 2020, 12:17am UTC](https://discourse.julialang.org/t/a-small-package-to-run-string-as-shell-command/6163 "2020-04-28T00:17:11Z")

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Building a string is easy, but building a Cmd is always a headache to me. So I write a small package to run strings as Cmd. Here is the task that drives me to write the package: There are some sub-folders containing .pn…

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## [Dev local package not working for test-specific dependencies](https://discourse.julialang.org/t/dev-local-package-not-working-for-test-specific-dependencies/38343)

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**Author:** [@yiyuezhuo](https://discourse.julialang.org/u/yiyuezhuo)\
**Replies:** 0\
**Last updated:** [April 27, 2020, 11:38pm UTC](https://discourse.julialang.org/t/dev-local-package-not-working-for-test-specific-dependencies/38343 "2020-04-27T23:38:18Z")

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Let’s say there’re local packages PA, PB and PC. I can add PA to dependencies of PB using (PB) pkg\> dev /PA/local/path and get tests worked. But since PA is a test specific dependencies, when I add PA to test-specific …

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## [ERROR: TypeError: non-boolean (Int64) used in boolean context](https://discourse.julialang.org/t/error-typeerror-non-boolean-int64-used-in-boolean-context/38340)

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**Author:** [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Replies:** 4\
**Last updated:** [April 27, 2020, 10:49pm UTC](https://discourse.julialang.org/t/error-typeerror-non-boolean-int64-used-in-boolean-context/38340 "2020-04-27T22:49:11Z")

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Dear Julia users, My codes work in Julia 0.7.0, but when I tried to run them in Julia 1.0.5, I got the following error. It seems this error happens for multiple common Julia functions such as “findall” and etc… Any sugg…

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## [Using Distributions](https://discourse.julialang.org/t/using-distributions/38337)

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**Author:** [@Jing\_Zhang](https://discourse.julialang.org/u/Jing_Zhang)\
**Replies:** 3\
**Last updated:** [April 27, 2020, 10:36pm UTC](https://discourse.julialang.org/t/using-distributions/38337 "2020-04-27T22:36:04Z")

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Dear Julia Users, I got a problem with “using Distributions” for Julia 1.0.5. Please see below for details. Any idea would be appreciated. julia\> using Distributions \[ Info: Precompiling Distributions \[31c24e10-a181-5…

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## [Juno in Mac OS: mkdir: Permission denied](https://discourse.julialang.org/t/juno-in-mac-os-mkdir-permission-denied/17310)

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**Author:** [@Eric\_Chen](https://discourse.julialang.org/u/Eric_Chen)\
**Replies:** 7\
**Last updated:** [April 27, 2020, 10:28pm UTC](https://discourse.julialang.org/t/juno-in-mac-os-mkdir-permission-denied/17310 "2020-04-27T22:28:40Z")

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I installed JuliaPro 1.0.1 with Mac OS Mojave. I get this error when i start Juno IDE and Julia looks like permission issue but donno how to fix? thank you ERROR: SystemError (with /Users/Evveric/.julia/logs): mk…

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## [Underscore not displayed in the Juno's REPL](https://discourse.julialang.org/t/underscore-not-displayed-in-the-junos-repl/19670)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 23\
**Last updated:** [April 27, 2020, 10:26pm UTC](https://discourse.julialang.org/t/underscore-not-displayed-in-the-junos-repl/19670 "2020-04-27T22:26:39Z")

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Hi, The underscore character appears as a white space in my Juno’s REPL. Do you have similar experience ?

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## [Tree limit JuMP 0.21](https://discourse.julialang.org/t/tree-limit-jump-0-21/38135)

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**Author:** [@baprata](https://discourse.julialang.org/u/baprata)\
**Replies:** 2\
**Last updated:** [April 27, 2020, 8:43pm UTC](https://discourse.julialang.org/t/tree-limit-jump-0-21/38135 "2020-04-27T20:43:43Z")

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I am modeling an optimization problem within Julia/Atom and CPLEX. I need to control the tree limit size. What is the syntax for the tree limit in JuMP 0.21? Thanks in advance, Bruno

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## [\[ANN\]: StaticKernels.jl - Fast Kernel Operations on Arrays](https://discourse.julialang.org/t/ann-statickernels-jl-fast-kernel-operations-on-arrays/37658)

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**Author:** [@stev47](https://discourse.julialang.org/u/stev47)\
**Replies:** 24\
**Last updated:** [April 27, 2020, 8:36pm UTC](https://discourse.julialang.org/t/ann-statickernels-jl-fast-kernel-operations-on-arrays/37658 "2020-04-27T20:36:45Z")

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StaticKernels.jl is a new package that aims to enable easy and fast execution of kernel operations on arrays, e.g. finite differences, convolutions, image filters and morphological operations, etc. custom kernel functi…

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## [Accessing all definitions in a module](https://discourse.julialang.org/t/accessing-all-definitions-in-a-module/37936)

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**Author:** [@ckfinite](https://discourse.julialang.org/u/ckfinite)\
**Replies:** 6\
**Last updated:** [April 27, 2020, 7:54pm UTC](https://discourse.julialang.org/t/accessing-all-definitions-in-a-module/37936 "2020-04-27T19:54:57Z")

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For a program analysis tool I’m working on, I need to know about all available functions. However, the traditional suggestion using names does not work for me, with the canonical example happening with NamedTuples. The (…

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## [Deactivating and reactivating JuMP constraints](https://discourse.julialang.org/t/deactivating-and-reactivating-jump-constraints/38315)

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**Author:** [@Tomas\_Uribe](https://discourse.julialang.org/u/Tomas_Uribe)\
**Replies:** 1\
**Last updated:** [April 27, 2020, 7:33pm UTC](https://discourse.julialang.org/t/deactivating-and-reactivating-jump-constraints/38315 "2020-04-27T19:33:44Z")

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Is there a way to deactivate and reactivate JuMP constraints that are tied to a model? I found delete(model, constraint), but once deleted, constraints can’t be added back again.

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## [Go back to var?](https://discourse.julialang.org/t/go-back-to-var/38293)

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**Author:** [@pixel27](https://discourse.julialang.org/u/pixel27)\
**Replies:** 4\
**Last updated:** [April 27, 2020, 6:05pm UTC](https://discourse.julialang.org/t/go-back-to-var/38293 "2020-04-27T18:05:42Z")

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I debated bringing this up, but I fear if I don’t it will just keep rattling around in my head. I suspect the answer will be “The upheaval from this change would be too much”, so I’m not really expecting it to go into 2…

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## [String representation of hexadecimal to unicode character](https://discourse.julialang.org/t/string-representation-of-hexadecimal-to-unicode-character/38289)

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**Author:** [@HugoTrentesaux](https://discourse.julialang.org/u/HugoTrentesaux)\
**Replies:** 4\
**Last updated:** [April 27, 2020, 5:12pm UTC](https://discourse.julialang.org/t/string-representation-of-hexadecimal-to-unicode-character/38289 "2020-04-27T17:12:00Z")

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Is there a builtin function to transform the string representation of an hexadecimal to the corresponding unicode character? # we can for example do julia\> Char(0x03C0) 'π': Unicode U+03c0 (category Ll: Letter, lowercas…

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## [Dynamically invoke all the methods of a function](https://discourse.julialang.org/t/dynamically-invoke-all-the-methods-of-a-function/38258)

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**Author:** [@essenciary](https://discourse.julialang.org/u/essenciary)\
**Replies:** 8\
**Last updated:** [April 27, 2020, 3:35pm UTC](https://discourse.julialang.org/t/dynamically-invoke-all-the-methods-of-a-function/38258 "2020-04-27T15:35:10Z")

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I want to write a function A.x() which in its body automatically invokes all the available methods of A.x(). However, I can’t find the reflection mechanism that allows me to do this. I was hoping methods will do it, but …

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## [Using Cassette to overdub just some methods](https://discourse.julialang.org/t/using-cassette-to-overdub-just-some-methods/38139)

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**Author:** [@lino98](https://discourse.julialang.org/u/lino98)\
**Replies:** 6\
**Last updated:** [April 27, 2020, 3:29pm UTC](https://discourse.julialang.org/t/using-cassette-to-overdub-just-some-methods/38139 "2020-04-27T15:29:52Z")

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I’m working on developing a software that mesure performance of a julia program and i’m using cassette since i have to intercept function calls and modify them, the problem is that when i overdub a function it recursivel…

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## [Auto-Installing Dependencies](https://discourse.julialang.org/t/auto-installing-dependencies/38312)

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**Author:** [@themadprogramer](https://discourse.julialang.org/u/themadprogramer)\
**Replies:** 1\
**Last updated:** [April 27, 2020, 3:21pm UTC](https://discourse.julialang.org/t/auto-installing-dependencies/38312 "2020-04-27T15:21:33Z")

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So let’s say I have a project with dependencies. I could them to install with Pkg.add() But I’ve also read a bit about Project.toml and Manifest.toml , which seem a lot cleaner. I don’t quite get if or how they aut…

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## [InteractiveChaos: Absurdly fast, general-purpose applications for dynamical systems](https://discourse.julialang.org/t/interactivechaos-absurdly-fast-general-purpose-applications-for-dynamical-systems/38244)

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**Author:** [@Datseris](https://discourse.julialang.org/u/Datseris)\
**Replies:** 7\
**Last updated:** [April 27, 2020, 3:20pm UTC](https://discourse.julialang.org/t/interactivechaos-absurdly-fast-general-purpose-applications-for-dynamical-systems/38244 "2020-04-27T15:20:59Z")

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(there was a post about this in the past, but its now a full fledged package) Mandatory eye-candy to get your attention: InteractiveChaos.jl is a Julia package that builds on top of the packages of JuliaDynamics to…

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## [Native Julia Mirror for packages and registries](https://discourse.julialang.org/t/native-julia-mirror-for-packages-and-registries/38304)

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**Author:** [@Alireza\_Ghavaminia](https://discourse.julialang.org/u/Alireza_Ghavaminia)\
**Replies:** 0\
**Last updated:** [April 27, 2020, 2:07pm UTC](https://discourse.julialang.org/t/native-julia-mirror-for-packages-and-registries/38304 "2020-04-27T14:07:21Z")

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Hello everyone, I have written a program that can create and maintain a mirror of the Julia packages (Link). This program is useful for anyone who wants to keep access to the Julia packages behind a restricted network o…

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## [Reporting errors with source code position?](https://discourse.julialang.org/t/reporting-errors-with-source-code-position/38288)

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**Author:** [@thautwarm](https://discourse.julialang.org/u/thautwarm)\
**Replies:** 3\
**Last updated:** [April 27, 2020, 2:02pm UTC](https://discourse.julialang.org/t/reporting-errors-with-source-code-position/38288 "2020-04-27T14:02:11Z")

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Is there any standard rules for reporting errors when metaprogramming? For the cases that users give wrong data in runtime or they do not properly use a macro, I want to report them the concrete error message with accur…

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## [Lagrangian Function](https://discourse.julialang.org/t/lagrangian-function/38287)

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**Author:** [@mayar](https://discourse.julialang.org/u/mayar)\
**Replies:** 18\
**Last updated:** [April 27, 2020, 1:04pm UTC](https://discourse.julialang.org/t/lagrangian-function/38287 "2020-04-27T13:04:43Z")

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Hello everyone, I am trying to solve an optimization problem by using the lagrangian function, which package is best suited for this task specially because I need the equality constraint multipliers to be returned as th…

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## [Advice on approximating Complicated integral](https://discourse.julialang.org/t/advice-on-approximating-complicated-integral/38235)

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**Author:** [@francesco.alemanno](https://discourse.julialang.org/u/francesco.alemanno)\
**Replies:** 4\
**Last updated:** [April 27, 2020, 1:03pm UTC](https://discourse.julialang.org/t/advice-on-approximating-complicated-integral/38235 "2020-04-27T13:03:35Z")

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hi everyone i’m trying to solve a system of fixed point equations that involve integrals of this type. so far nesting quadgk calls results with high probability in a domain error, the only thing that helps is using Bi…

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## [Can \`load\` work faster?](https://discourse.julialang.org/t/can-load-work-faster/38291)

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**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 3\
**Last updated:** [April 27, 2020, 1:00pm UTC](https://discourse.julialang.org/t/can-load-work-faster/38291 "2020-04-27T13:00:39Z")

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I have to load many files in a loop (to be more specific, I’m working with OBJ files to be used with MeshIO). I guess that including a line like load(filename) in the loop, with filename being a string with the file path…

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## [Problems with juno](https://discourse.julialang.org/t/problems-with-juno/38292)

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**Author:** [@asb](https://discourse.julialang.org/u/asb)\
**Replies:** 0\
**Last updated:** [April 27, 2020, 11:18am UTC](https://discourse.julialang.org/t/problems-with-juno/38292 "2020-04-27T11:18:32Z")

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I installed JuliaPro on a system running Ubuntu 16.04 LTS. When I typed at the terminal prompt JuliaPro the Juno interface opened, and if I pressed “Enter” in the correct window, Julia would start. I recently did a…

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## [Starting Scripts with multiple threads](https://discourse.julialang.org/t/starting-scripts-with-multiple-threads/38014)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 2\
**Last updated:** [April 27, 2020, 11:10am UTC](https://discourse.julialang.org/t/starting-scripts-with-multiple-threads/38014 "2020-04-27T11:10:27Z")

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I read Parallel Computing · The Julia Language and Getting Started · The Julia Language but can’t start Julia on Windows 10 with multiple threads. Questions: What is the difference between julia -p auto to start julia…

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