# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1714

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

**Page:** 1715

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## [FORTRAN STOP leads to exiting Julia REPL](https://discourse.julialang.org/t/fortran-stop-leads-to-exiting-julia-repl/41643)

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**Author:** [@mopg](https://discourse.julialang.org/u/mopg)\
**Replies:** 2\
**Last updated:** [June 18, 2020, 3:36am UTC](https://discourse.julialang.org/t/fortran-stop-leads-to-exiting-julia-repl/41643 "2020-06-18T03:36:23Z")

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I am wrapping a FORTRAN library that has a bunch of STOP commands in it (to throw errors). However, when I call the library from Julia and one of those errors is reached, the whole process exits (including the Julia REPL…

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## [Compiling Clones for Fun and Profit](https://discourse.julialang.org/t/compiling-clones-for-fun-and-profit/41516)

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**Author:** [@brotherjack](https://discourse.julialang.org/u/brotherjack)\
**Replies:** 12\
**Last updated:** [June 18, 2020, 3:28am UTC](https://discourse.julialang.org/t/compiling-clones-for-fun-and-profit/41516 "2020-06-18T03:28:24Z")

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Hello, uh, Juliaistas? Juliaverse? As part of my Julia journey, I have decided to work on a TCX parser (specifically this parser xue35/TCX.jl that would be useful for getting to my fitness data. While I have managed to…

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## [Can't install any packages](https://discourse.julialang.org/t/cant-install-any-packages/41626)

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**Author:** [@nstgc](https://discourse.julialang.org/u/nstgc)\
**Replies:** 18\
**Last updated:** [June 18, 2020, 1:01am UTC](https://discourse.julialang.org/t/cant-install-any-packages/41626 "2020-06-18T01:01:05Z")

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I’ve been using Julia for six years. I moved to it from Python, but one thing I absolutely cannot do is install packages. So today when I saw a graph in Wolfram Alpha that didn’t look right (eventually I found the root i…

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## [Identifying nodes in a Graph](https://discourse.julialang.org/t/identifying-nodes-in-a-graph/41498)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 4\
**Last updated:** [June 17, 2020, 10:13pm UTC](https://discourse.julialang.org/t/identifying-nodes-in-a-graph/41498 "2020-06-17T22:13:13Z")

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Hi, I have data on users for whom I’d like to create a bipartite network that connects them through their consumption decisions. Since the data is rather big I’m trying to find an efficient implementation to create the …

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## [Do comprehensions implicitly use sizehint?](https://discourse.julialang.org/t/do-comprehensions-implicitly-use-sizehint/41452)

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**Author:** [@nacnudus](https://discourse.julialang.org/u/nacnudus)\
**Replies:** 3\
**Last updated:** [June 17, 2020, 9:33pm UTC](https://discourse.julialang.org/t/do-comprehensions-implicitly-use-sizehint/41452 "2020-06-17T21:33:35Z")

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The Wikibook on creating dictionaries gives an example that uses a comprehension. Would Julia automatically use a sizehint based on the size of for i = 0:5:360? Or would it be better to do that explicitly by creating a…

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## [Problem about using DiscreteCallback function in solving ODE problem](https://discourse.julialang.org/t/problem-about-using-discretecallback-function-in-solving-ode-problem/41624)

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**Author:** [@XiaodongMa-MRI](https://discourse.julialang.org/u/XiaodongMa-MRI)\
**Replies:** 4\
**Last updated:** [June 17, 2020, 7:54pm UTC](https://discourse.julialang.org/t/problem-about-using-discretecallback-function-in-solving-ode-problem/41624 "2020-06-17T19:54:11Z")

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Hello everyone, I am a PostDoc in Department of Radiology, University of Minnesota. I want to use Julia to solve an ODE problem, where the user-provided parameter p is changed dynamically. I refered to several topics in…

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## [Debugging Flux NaN problem](https://discourse.julialang.org/t/debugging-flux-nan-problem/41625)

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**Author:** [@d1cker](https://discourse.julialang.org/u/d1cker)\
**Replies:** 0\
**Last updated:** [June 17, 2020, 7:35pm UTC](https://discourse.julialang.org/t/debugging-flux-nan-problem/41625 "2020-06-17T19:35:16Z")

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Hi, I’m trying to learn Reinforcement learning using Julia. I tried to implement Reinforce algorithm (simple gradient policy) using Julia and Flux, basically translating this Python code. That is my try: using PyCall …

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## [Using Pardiso with Ipopt/JuMP, install custom built Ipopt binaries](https://discourse.julialang.org/t/using-pardiso-with-ipopt-jump-install-custom-built-ipopt-binaries/41623)

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**Author:** [@dadada\_dadada](https://discourse.julialang.org/u/dadada_dadada)\
**Replies:** 0\
**Last updated:** [June 17, 2020, 7:04pm UTC](https://discourse.julialang.org/t/using-pardiso-with-ipopt-jump-install-custom-built-ipopt-binaries/41623 "2020-06-17T19:04:27Z")

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Hello, I’m trying to use Ipopt with pardiso linear solver. I am trying to install its libraries with the commands given in the Ipopt.jl readme. I got the following files libpardiso600-WIN-X86-64.dll libpardiso600-WIN-X…

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## [\`LoadError: value not writable for any mimetypes\` is thrown when plotting from @manipulate in Interact.jl](https://discourse.julialang.org/t/loaderror-value-not-writable-for-any-mimetypes-is-thrown-when-plotting-from-manipulate-in-interact-jl/29476)

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**Author:** [@KestutisMa](https://discourse.julialang.org/u/KestutisMa)\
**Replies:** 1\
**Last updated:** [June 17, 2020, 6:47pm UTC](https://discourse.julialang.org/t/loaderror-value-not-writable-for-any-mimetypes-is-thrown-when-plotting-from-manipulate-in-interact-jl/29476 "2020-06-17T18:47:54Z")

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I am using modified @manipulate example from Tutorial · Interact and got LoadError: value not writable for any mimetypes. If I replace line Makie.plot(x,y) with print(y) then code is working. Makie.plot() function is w…

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## [Why the inner constructor of a template structure returns "too few type parameters" error?](https://discourse.julialang.org/t/why-the-inner-constructor-of-a-template-structure-returns-too-few-type-parameters-error/41441)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 11\
**Last updated:** [June 17, 2020, 6:03pm UTC](https://discourse.julialang.org/t/why-the-inner-constructor-of-a-template-structure-returns-too-few-type-parameters-error/41441 "2020-06-17T18:03:11Z")

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Why the following code: mutable struct Test{T \<:Number} μ::Union{T,Nothing} σ²::Union{T,Nothing} Test(μ=nothing,σ²=nothing) = new(μ,σ²) end returns the error ERROR: syntax: too few type parameters specified…

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## [Annotating functions for analytic performance prediction](https://discourse.julialang.org/t/annotating-functions-for-analytic-performance-prediction/41485)

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**Author:** [@hros](https://discourse.julialang.org/u/hros)\
**Replies:** 6\
**Last updated:** [June 17, 2020, 5:57pm UTC](https://discourse.julialang.org/t/annotating-functions-for-analytic-performance-prediction/41485 "2020-06-17T17:57:14Z")

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I would like to add function meta data and reflection to accomplish the following (I’ll use a simplistic scenario): Say I building a big-data solutions (call it ‘g’) using a library of functions (‘f\_i’) )for performing:…

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## [How to extract substring of a Julia Dataframe column](https://discourse.julialang.org/t/how-to-extract-substring-of-a-julia-dataframe-column/41610)

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**Author:** [@Julia1](https://discourse.julialang.org/u/Julia1)\
**Replies:** 3\
**Last updated:** [June 17, 2020, 5:38pm UTC](https://discourse.julialang.org/t/how-to-extract-substring-of-a-julia-dataframe-column/41610 "2020-06-17T17:38:31Z")

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Hi, I may be overthinking this one, but all I’m trying to do is turn a column into a specific indexed substring of that column. df = DataFrame(number=\[123456,134553\]) df\[:number\] = string.(df\[:number\] All I want to do …

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## [Shuffling only non-missing values](https://discourse.julialang.org/t/shuffling-only-non-missing-values/41549)

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**Author:** [@pdimens](https://discourse.julialang.org/u/pdimens)\
**Replies:** 2\
**Last updated:** [June 17, 2020, 5:25pm UTC](https://discourse.julialang.org/t/shuffling-only-non-missing-values/41549 "2020-06-17T17:25:53Z")

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In trying to implement permutation functions in PopGen.jl, I came across a situation where I will need to shuffle values within some parameters (like genotypes across loci, or across loci across populations), and have to…

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## [Handle numerical values as categories in plots](https://discourse.julialang.org/t/handle-numerical-values-as-categories-in-plots/41256)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 4\
**Last updated:** [June 17, 2020, 4:57pm UTC](https://discourse.julialang.org/t/handle-numerical-values-as-categories-in-plots/41256 "2020-06-17T16:57:58Z")

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I am trying to plot boxplots of values with respect to 4 categories represented as numbers. The four categories are powers of two: 16384, 32768, 65536, 131072. Let’s use this MWE dataframe: using DataFrames, StatsPlots…

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## [\[ANN\] - MetaGraphs major changes coming](https://discourse.julialang.org/t/ann-metagraphs-major-changes-coming/33992)

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**Author:** [@anon94023334](https://discourse.julialang.org/u/anon94023334)\
**Replies:** 4\
**Last updated:** [June 17, 2020, 4:40pm UTC](https://discourse.julialang.org/t/ann-metagraphs-major-changes-coming/33992 "2020-06-17T16:40:09Z")

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Hi all, I just wanted to announce that we’ve released v0.6.5 of MetaGraphs, the LightGraphs-with-metadata package. This will be, hopefully, the final release of MetaGraphs before a fairly significant set of breaking cha…

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## [Euclidean distance from one point](https://discourse.julialang.org/t/euclidean-distance-from-one-point/41594)

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**Author:** [@Geoffrey](https://discourse.julialang.org/u/Geoffrey)\
**Replies:** 6\
**Last updated:** [June 17, 2020, 3:59pm UTC](https://discourse.julialang.org/t/euclidean-distance-from-one-point/41594 "2020-06-17T15:59:45Z")

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Hi, I’m looking for a way to compute an array representing the radius of the polar or spherical coordinates given the array sizes and a center point. I have this code for now but it’s incredibly slow and I’m looking for …

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## [Problems with titles, axes, grids and other plot properties using Makie](https://discourse.julialang.org/t/problems-with-titles-axes-grids-and-other-plot-properties-using-makie/41584)

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**Author:** [@jbpatzer](https://discourse.julialang.org/u/jbpatzer)\
**Replies:** 10\
**Last updated:** [June 17, 2020, 3:54pm UTC](https://discourse.julialang.org/t/problems-with-titles-axes-grids-and-other-plot-properties-using-makie/41584 "2020-06-17T15:54:21Z")

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I’m currently converting some code from MATLAB to Julia, and have reached the stage where I have to do some graphics. The picture shows the MATLAB plot on the right and my attempt in Julia using Makie.jl on the left.…

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## [Use of "end" in array element selection](https://discourse.julialang.org/t/use-of-end-in-array-element-selection/41598)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 3\
**Last updated:** [June 17, 2020, 3:27pm UTC](https://discourse.julialang.org/t/use-of-end-in-array-element-selection/41598 "2020-06-17T15:27:36Z")

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The end token means “last element of array”, and it is essentially equivalent to -1 in Python. However, that is not always true. Consider the array: a = collection(1:100) b = view(a, 1:20) c = view(a, 30:end) I get the…

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## [Persistently dirty registry .... case-insensitive file collision when cloning JuliaRegistries/General from GitHub](https://discourse.julialang.org/t/persistently-dirty-registry-case-insensitive-file-collision-when-cloning-juliaregistries-general-from-github/41577)

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**Author:** [@lyonsquark](https://discourse.julialang.org/u/lyonsquark)\
**Replies:** 6\
**Last updated:** [June 17, 2020, 3:26pm UTC](https://discourse.julialang.org/t/persistently-dirty-registry-case-insensitive-file-collision-when-cloning-juliaregistries-general-from-github/41577 "2020-06-17T15:26:41Z")

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Many Pkg commands are giving me Warning: Some registries failed to update: │ — \`~/.julia/registries/General\` — registry dirty and \] update does not work. Looking at my ~/.julia/registries/General, there are files…

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## [Grouping in Julia plots](https://discourse.julialang.org/t/grouping-in-julia-plots/41596)

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**Author:** [@gedankenexperiment](https://discourse.julialang.org/u/gedankenexperiment)\
**Replies:** 7\
**Last updated:** [June 17, 2020, 3:15pm UTC](https://discourse.julialang.org/t/grouping-in-julia-plots/41596 "2020-06-17T15:15:40Z")

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Hi there, Let’s say I have a dataframe I want to plot. I know that I can use the keyword argument group to select a column and to have a grouping for the different cases. But what if I would like to manually group toget…

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## [The 2020 Julia language survey is live now](https://discourse.julialang.org/t/the-2020-julia-language-survey-is-live-now/41002)

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**Author:** [@viralbshah](https://discourse.julialang.org/u/viralbshah)\
**Replies:** 14\
**Last updated:** [June 17, 2020, 2:55pm UTC](https://discourse.julialang.org/t/the-2020-julia-language-survey-is-live-now/41002 "2020-06-17T14:55:32Z")

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The 2020 User & Developer Survey closes Sunday June 28. Complete it today! Take the survey now in English, Spanish, Japanese or Chinese. Findings will be presented at JuliaCon, just like last year.

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## [Apache Zeppelin and Julia](https://discourse.julialang.org/t/apache-zeppelin-and-julia/41587)

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**Author:** [@lungben](https://discourse.julialang.org/u/lungben)\
**Replies:** 0\
**Last updated:** [June 17, 2020, 12:30pm UTC](https://discourse.julialang.org/t/apache-zeppelin-and-julia/41587 "2020-06-17T12:30:15Z")

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Hi, I recently came across Apache Zeppelin, which is somewhat similar to Jupyter (and actually supports Jupyter / IPython notebooks), but more focussed on big data and multi-user capabilities. Especially the latter make…

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## [Beyond technical computing and powering static site generators, what has Julia been used for?](https://discourse.julialang.org/t/beyond-technical-computing-and-powering-static-site-generators-what-has-julia-been-used-for/41299)

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**Author:** [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Replies:** 19\
**Last updated:** [June 17, 2020, 11:31am UTC](https://discourse.julialang.org/t/beyond-technical-computing-and-powering-static-site-generators-what-has-julia-been-used-for/41299 "2020-06-17T11:31:10Z")

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I was just curious as to what use Julia has found so far outside of technical computing and powering static site generators. After all, it’s a general-purpose programming language, so I’d imagine it would have found use …

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## [Getting gradients for DiffEq with single derivative](https://discourse.julialang.org/t/getting-gradients-for-diffeq-with-single-derivative/41519)

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**Author:** [@Janssena](https://discourse.julialang.org/u/Janssena)\
**Replies:** 3\
**Last updated:** [June 17, 2020, 11:06am UTC](https://discourse.julialang.org/t/getting-gradients-for-diffeq-with-single-derivative/41519 "2020-06-17T11:06:52Z")

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Hey All, I’ve been meaning to calculate the gradient of an ODEProblem using Zygote, OrdinaryDiffEq, and DiffEqSensitivity. I’ve been running into a wide scala of errors along the way but found a way to do it. So initia…

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## [Batch size and early stopping in Flux](https://discourse.julialang.org/t/batch-size-and-early-stopping-in-flux/41517)

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**Author:** [@Mariana](https://discourse.julialang.org/u/Mariana)\
**Replies:** 5\
**Last updated:** [June 17, 2020, 10:56am UTC](https://discourse.julialang.org/t/batch-size-and-early-stopping-in-flux/41517 "2020-06-17T10:56:58Z")

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I´m starting to work with Flux and I have a neural network with 63 entries, 2 hidden layers and 1 exit. Each entry and exit is a vector of 113344 elements, from which 78801 elements belong to the training set and the rem…

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## [BinaryBuilder: enable compilers](https://discourse.julialang.org/t/binarybuilder-enable-compilers/41553)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 5\
**Last updated:** [June 17, 2020, 10:20am UTC](https://discourse.julialang.org/t/binarybuilder-enable-compilers/41553 "2020-06-17T10:20:48Z")

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I’m trying to start using BinaryBuilder but have no success even for the simplest cases. E.g. I download https://github.com/JuliaPackaging/Yggdrasil/blob/master/H/HelloWorldFortran/build\_tarballs.jl and run it as julia b…

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## [About memory allocation of auxiliary array in successive calls of a function](https://discourse.julialang.org/t/about-memory-allocation-of-auxiliary-array-in-successive-calls-of-a-function/41535)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 6\
**Last updated:** [June 17, 2020, 8:31am UTC](https://discourse.julialang.org/t/about-memory-allocation-of-auxiliary-array-in-successive-calls-of-a-function/41535 "2020-06-17T08:31:02Z")

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If I call a function that internally requires the allocation of an array for some computation, and afterwards I call this same function with the exact same type of input variables, is the auxiliary array which was alloca…

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## ['warn not defined'-issue when using Callbacks & Multithreaded Ensemble Simulations with DifferentialEquations.jl](https://discourse.julialang.org/t/warn-not-defined-issue-when-using-callbacks-multithreaded-ensemble-simulations-with-differentialequations-jl/41532)

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**Author:** [@luis\_munoz](https://discourse.julialang.org/u/luis_munoz)\
**Replies:** 2\
**Last updated:** [June 17, 2020, 7:06am UTC](https://discourse.julialang.org/t/warn-not-defined-issue-when-using-callbacks-multithreaded-ensemble-simulations-with-differentialequations-jl/41532 "2020-06-17T07:06:03Z")

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Hi, I am trying to use multithreading via EnsembleThreads() within a EnsembleProblem and apply a DiscreteCallback to terminate! the individual simulations under a certain condition. Unfortunately my simulation results i…

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## [What would you recommend for nolinear optimization with optional gradient and hessian](https://discourse.julialang.org/t/what-would-you-recommend-for-nolinear-optimization-with-optional-gradient-and-hessian/41555)

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**Author:** [@sunjin](https://discourse.julialang.org/u/sunjin)\
**Replies:** 5\
**Last updated:** [June 17, 2020, 5:40am UTC](https://discourse.julialang.org/t/what-would-you-recommend-for-nolinear-optimization-with-optional-gradient-and-hessian/41555 "2020-06-17T05:40:52Z")

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Hi, I am solving a numerical box-constrained nonlinear optimization problem with hundreds of unknowns. I currently implemented only the objective function but not the gradient or hessian. However, I expect to do so in th…

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## [Covert MainFrame EBCDIC files to ASCII using Julia](https://discourse.julialang.org/t/covert-mainframe-ebcdic-files-to-ascii-using-julia/41548)

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**Author:** [@siralfbaez](https://discourse.julialang.org/u/siralfbaez)\
**Replies:** 1\
**Last updated:** [June 17, 2020, 4:07am UTC](https://discourse.julialang.org/t/covert-mainframe-ebcdic-files-to-ascii-using-julia/41548 "2020-06-17T04:07:27Z")

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Hello Julia Geeks, I have these old functions that would take file coming from MainFrames with EBCDIC format then converts these to ASCII. Need your guidance to rewrite these into Julia so i can test the difference in p…

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