# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1517

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

**Page:** 1518

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## [Converting an Array of Byte to Array{T}](https://discourse.julialang.org/t/converting-an-array-of-byte-to-array-t/53676)

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**Author:** [@Clonkk](https://discourse.julialang.org/u/Clonkk)\
**Replies:** 2\
**Last updated:** [January 20, 2021, 4:25pm UTC](https://discourse.julialang.org/t/converting-an-array-of-byte-to-array-t/53676 "2021-01-20T16:25:31Z")

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Hello, I have binary data read from SQLite database in the form of Array{Uint8}. What would be the best solution to convert this binary data into an Array{T} (convert function perform element wise conversion and thus d…

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## [Expected speed of WGLMakie](https://discourse.julialang.org/t/expected-speed-of-wglmakie/53673)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 0\
**Last updated:** [January 20, 2021, 3:24pm UTC](https://discourse.julialang.org/t/expected-speed-of-wglmakie/53673 "2021-01-20T15:24:38Z")

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Hi, I wonder what is the expected speed of WGLMakie compared to GLMakie. The following MWE takes 20s with WGLMakie compared to 0.8s using GLMakie. Is is expected ? Could someone explain the difference ? MWEusing GLMak…

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## [Problems to install CPLEX v 20.10](https://discourse.julialang.org/t/problems-to-install-cplex-v-20-10/53669)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 4\
**Last updated:** [January 20, 2021, 3:07pm UTC](https://discourse.julialang.org/t/problems-to-install-cplex-v-20-10/53669 "2021-01-20T15:07:49Z")

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Dear all, I had the software CPLEX v 12.8 on my computer and I worked with Julia. Recently, I have removed this version and updated to version 20.10 of this software. In the instalation of new version I had installed o…

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## [Turing error with truncated distribution](https://discourse.julialang.org/t/turing-error-with-truncated-distribution/53418)

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**Author:** [@BradGroff](https://discourse.julialang.org/u/BradGroff)\
**Replies:** 1\
**Last updated:** [January 20, 2021, 1:08pm UTC](https://discourse.julialang.org/t/turing-error-with-truncated-distribution/53418 "2021-01-20T13:08:17Z")

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Hi, I’m trying to use a truncated distribution within an @model block of the form data ~ truncated(D(parameter), l, u)). This doesn’t seem to work :frowning: . Here’s the full example: @model function decay\_estimator\_t…

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## [SymPy, jacobians, and Euler-Lagrange?](https://discourse.julialang.org/t/sympy-jacobians-and-euler-lagrange/53666)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 0\
**Last updated:** [January 20, 2021, 1:03pm UTC](https://discourse.julialang.org/t/sympy-jacobians-and-euler-lagrange/53666 "2021-01-20T13:03:16Z")

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I’m trying to use SymPy to check some hand calculations regarding the use of the Euler-Lagrange equation. However, I get stuck because I cannot find functions for Jacobians, etc. in SymPy… First, I define generalized co…

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## [Trailing zeros](https://discourse.julialang.org/t/trailing-zeros/53549)

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**Author:** [@saraflgarcia](https://discourse.julialang.org/u/saraflgarcia)\
**Replies:** 13\
**Last updated:** [January 20, 2021, 10:39am UTC](https://discourse.julialang.org/t/trailing-zeros/53549 "2021-01-20T10:39:55Z")

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Hi everyone, I want to convert a number to a string, but keeping the trailing zeros: string(1) \> “1” string(1.0) \> “1.0” string(1.00) \> “1.0” - How do I get the result “1.00”? Thanks to all.

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## [Failure to run CUDA.jl](https://discourse.julialang.org/t/failure-to-run-cuda-jl/53657)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 3\
**Last updated:** [January 20, 2021, 10:07am UTC](https://discourse.julialang.org/t/failure-to-run-cuda-jl/53657 "2021-01-20T10:07:34Z")

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Hi, I just installed julia 1.5.3 and CUDA.jl in an office computer that runs ubuntu 18.04 and that has old UCDA drivers (from a couple of years ago). I can install CUDA.jl but when I try to use it, if fails to start and…

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## [Passing data through function calls](https://discourse.julialang.org/t/passing-data-through-function-calls/53656)

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**Author:** [@Peter-Jolly](https://discourse.julialang.org/u/Peter-Jolly)\
**Replies:** 5\
**Last updated:** [January 20, 2021, 9:36am UTC](https://discourse.julialang.org/t/passing-data-through-function-calls/53656 "2021-01-20T09:36:45Z")

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Hi, Below is a small demo program that is working. The idea I am exploring is for a function (main in this case) to call a function (data in this case) that generates some data c and d. This data is then passed back to …

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## [Looking for code to solve (surely common) 'embarrassing parallelism' multithreading use-case](https://discourse.julialang.org/t/looking-for-code-to-solve-surely-common-embarrassing-parallelism-multithreading-use-case/53527)

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**Author:** [@Sean\_Matthews](https://discourse.julialang.org/u/Sean_Matthews)\
**Replies:** 16\
**Last updated:** [January 20, 2021, 6:12am UTC](https://discourse.julialang.org/t/looking-for-code-to-solve-surely-common-embarrassing-parallelism-multithreading-use-case/53527 "2021-01-20T06:12:06Z")

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I am looking for code that can solve the following (multi-core, shared memory) parallelisation problem, which is surely so common that a well implemented solution must exist out there. I have N cores. I have a list (…

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## [Gadfly plot failing (suspect numerical issues)](https://discourse.julialang.org/t/gadfly-plot-failing-suspect-numerical-issues/53576)

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**Author:** [@JonT](https://discourse.julialang.org/u/JonT)\
**Replies:** 4\
**Last updated:** [January 20, 2021, 4:49am UTC](https://discourse.julialang.org/t/gadfly-plot-failing-suspect-numerical-issues/53576 "2021-01-20T04:49:24Z")

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I have a situation where I am trying to plot errors, which are small but are nowhere near subnormal numbers in Float64. Unfortunately, plot() is producing an incorrect graph, using Gadfly 1.3.1 in Julia 1.5.3. Here is …

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## [Numerical questions about spatially varying parameters for ParallelStencil.jl](https://discourse.julialang.org/t/numerical-questions-about-spatially-varying-parameters-for-parallelstencil-jl/53558)

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**Author:** [@ziyiyin97](https://discourse.julialang.org/u/ziyiyin97)\
**Replies:** 4\
**Last updated:** [January 20, 2021, 4:44am UTC](https://discourse.julialang.org/t/numerical-questions-about-spatially-varying-parameters-for-parallelstencil-jl/53558 "2021-01-20T04:44:42Z")

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Hi developers for ParallelStencil.jl, Hope you stepped into the new year with ease. I have experienced with your julia software in a while, thanks to your clear documentation and workflow! I have a couple of questions …

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## ["InexactError" when calling Optim](https://discourse.julialang.org/t/inexacterror-when-calling-optim/53568)

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**Author:** [@Michael\_Barmann](https://discourse.julialang.org/u/Michael_Barmann)\
**Replies:** 3\
**Last updated:** [January 19, 2021, 10:22pm UTC](https://discourse.julialang.org/t/inexacterror-when-calling-optim/53568 "2021-01-19T22:22:33Z")

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I’m writing a program to perform parameter estimation on a system of ODEs, and I keep getting this weird “InexactError” that I’ve spent hours unsuccessfully trying to figure out. Here is my call to the optimizer which i…

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## [MLJ: accessing model fields from resampler](https://discourse.julialang.org/t/mlj-accessing-model-fields-from-resampler/53551)

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**Author:** [@Pere](https://discourse.julialang.org/u/Pere)\
**Replies:** 4\
**Last updated:** [January 19, 2021, 9:37pm UTC](https://discourse.julialang.org/t/mlj-accessing-model-fields-from-resampler/53551 "2021-01-19T21:37:40Z")

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I have a composite model that has a parameter (alpha) that generates a probability distribution and then the features and samples are weighted according to this distribution. I also want the samples to be taken according…

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## [Compatibility between Theia and the Julia VS Code extension](https://discourse.julialang.org/t/compatibility-between-theia-and-the-julia-vs-code-extension/46047)

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**Author:** [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Replies:** 10\
**Last updated:** [January 19, 2021, 9:04pm UTC](https://discourse.julialang.org/t/compatibility-between-theia-and-the-julia-vs-code-extension/46047 "2021-01-19T21:04:42Z")

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I discovered Theia as a possible alternative to VS code in this thread, and decided to give it a try. It looks like a lot of features from the Julia VScode extension work out of the box, which is in itself an incredible…

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## [Extract a ZipFile](https://discourse.julialang.org/t/extract-a-zipfile/53577)

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**Author:** [@Rodrigo\_Roa](https://discourse.julialang.org/u/Rodrigo_Roa)\
**Replies:** 4\
**Last updated:** [January 19, 2021, 8:07pm UTC](https://discourse.julialang.org/t/extract-a-zipfile/53577 "2021-01-19T20:07:17Z")

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I am new to Juilia, and i’m doing a project that needs download free-access files, but they are in ZIP format, and i wanna know how extract them, because when i tried to do it whit the ZipFile.Reader function it throws m…

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## [Different dict iteration order between runs when altering unrelated code](https://discourse.julialang.org/t/different-dict-iteration-order-between-runs-when-altering-unrelated-code/53622)

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**Author:** [@paulmelis](https://discourse.julialang.org/u/paulmelis)\
**Replies:** 3\
**Last updated:** [January 19, 2021, 7:18pm UTC](https://discourse.julialang.org/t/different-dict-iteration-order-between-runs-when-altering-unrelated-code/53622 "2021-01-19T19:18:42Z")

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I’m working on a game simulation. It uses a fixed set of input files to initialize all game state with. To generate random choices I have a single MersenneTwister instance that I allocate at startup, the seed passed to i…

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## [Positioning a volume with Makie](https://discourse.julialang.org/t/positioning-a-volume-with-makie/53621)

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**Author:** [@Flausi](https://discourse.julialang.org/u/Flausi)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 6:54pm UTC](https://discourse.julialang.org/t/positioning-a-volume-with-makie/53621 "2021-01-19T18:54:04Z")

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Hello, I would like to plot a three-dimensional matrix as a volume at an arbitrary location in space with Makie.jl. using GLMakie using AbstractPlotting x = LinRange(1, 200, 200) y = LinRange(1, 200, 200) z = LinRange(…

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## [Import custom Julia module from C & use it](https://discourse.julialang.org/t/import-custom-julia-module-from-c-use-it/43979)

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**Author:** [@Clonkk](https://discourse.julialang.org/u/Clonkk)\
**Replies:** 3\
**Last updated:** [July 30, 2020, 2:08pm UTC](https://discourse.julialang.org/t/import-custom-julia-module-from-c-use-it/43979 "2020-07-30T14:08:02Z")

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Hello, I’m trying to import a local Julia module from C and call a function; but jl\_get\_function always return a null pointer. I based my code on this topic and this SO question, but nothing I’ve tried worked. This i…

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## [Embedding a custom Julia module in C++](https://discourse.julialang.org/t/embedding-a-custom-julia-module-in-c/53628)

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**Author:** [@JuliaPerson](https://discourse.julialang.org/u/JuliaPerson)\
**Replies:** 0\
**Last updated:** [January 19, 2021, 6:29pm UTC](https://discourse.julialang.org/t/embedding-a-custom-julia-module-in-c/53628 "2021-01-19T18:29:00Z")

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Hello, I’m trying to do something very similar to Import custom Julia module from C & use it: but in C++. I’ve tried compiling this example in C++, but I am receiving null output from the function. As suggested, I’m doi…

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## [Why is reversediff slow?](https://discourse.julialang.org/t/why-is-reversediff-slow/53541)

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**Author:** [@fmeulen](https://discourse.julialang.org/u/fmeulen)\
**Replies:** 11\
**Last updated:** [January 19, 2021, 6:02pm UTC](https://discourse.julialang.org/t/why-is-reversediff-slow/53541 "2021-01-19T18:02:00Z")

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I am trying to use automatic differentiation to obtain the gradient of a function with scalar-valued output. Contrary to what I had expected, reverse differentiation is much slower than forward differentiation. Can anyo…

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## [Warm-starting (set\_start\_value function) does not work in JuMP](https://discourse.julialang.org/t/warm-starting-set-start-value-function-does-not-work-in-jump/53620)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 5:59pm UTC](https://discourse.julialang.org/t/warm-starting-set-start-value-function-does-not-work-in-jump/53620 "2021-01-19T17:59:27Z")

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Dear All, I am trying to solve the following SDP with warm starting. The code is as follows using JuMP, COSMO # data m = 5 n = 10 using Random: bitrand c = randn(n) x0 = bitrand(n) A = randn(m, n) b = A \* x0 x\_pr…

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## [Would it be possible to update the documentation to include how to implement isequal() and hash()](https://discourse.julialang.org/t/would-it-be-possible-to-update-the-documentation-to-include-how-to-implement-isequal-and-hash/53518)

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**Author:** [@anon60034542](https://discourse.julialang.org/u/anon60034542)\
**Replies:** 14\
**Last updated:** [January 19, 2021, 5:48pm UTC](https://discourse.julialang.org/t/would-it-be-possible-to-update-the-documentation-to-include-how-to-implement-isequal-and-hash/53518 "2021-01-19T17:48:42Z")

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Both the C# and Python documentation include clear instructions on how to implement equals and hash code methods and I was wondering if we could do the same for Julia. For example, the Base.hash() documentation says: N…

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## [ArgumentError ReverseDiff: cannot reinterpret](https://discourse.julialang.org/t/argumenterror-reversediff-cannot-reinterpret/53618)

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**Author:** [@fmeulen](https://discourse.julialang.org/u/fmeulen)\
**Replies:** 4\
**Last updated:** [January 19, 2021, 5:45pm UTC](https://discourse.julialang.org/t/argumenterror-reversediff-cannot-reinterpret/53618 "2021-01-19T17:45:50Z")

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I attempt to used reverse mode differentiation. A very much simplified version of the function call is using StaticArrays using ReverseDiff const Po{T} = SArray{Tuple{2},T,1,2} # point in R2 function ff(x) T …

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## [Simulated Method of Moments / Indirect inference: how might ModelingToolkit be extended to provide convenient user inteface?](https://discourse.julialang.org/t/simulated-method-of-moments-indirect-inference-how-might-modelingtoolkit-be-extended-to-provide-convenient-user-inteface/53395)

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**Author:** [@croberts](https://discourse.julialang.org/u/croberts)\
**Replies:** 16\
**Last updated:** [January 19, 2021, 5:39pm UTC](https://discourse.julialang.org/t/simulated-method-of-moments-indirect-inference-how-might-modelingtoolkit-be-extended-to-provide-convenient-user-inteface/53395 "2021-01-19T17:39:55Z")

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I am looking to estimate a simulated method of moments model. The most similar thread on SMM is from 2019 but does not settle issues: The most similar thread is: Global optimization: Simulated Method of Moments . Julia…

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## [\[ANN\] GHCNData.jl - Helper functionality for accessing and parsing the Global Historical Climatology Network daily data archive](https://discourse.julialang.org/t/ann-ghcndata-jl-helper-functionality-for-accessing-and-parsing-the-global-historical-climatology-network-daily-data-archive/53624)

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**Author:** [@willtebbutt](https://discourse.julialang.org/u/willtebbutt)\
**Replies:** 1\
**Last updated:** [January 19, 2021, 5:30pm UTC](https://discourse.julialang.org/t/ann-ghcndata-jl-helper-functionality-for-accessing-and-parsing-the-global-historical-climatology-network-daily-data-archive/53624 "2021-01-19T17:30:40Z")

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GHCNData.jl is a small package for getting hold of the data from NOAA and parsing it. I wrote it as part of a larger project and figured other people might find it useful. Possibly the most helpful bit of the package is…

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## [Automatic inverse of a function?](https://discourse.julialang.org/t/automatic-inverse-of-a-function/53342)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 17\
**Last updated:** [January 19, 2021, 5:28pm UTC](https://discourse.julialang.org/t/automatic-inverse-of-a-function/53342 "2021-01-19T17:28:51Z")

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Hey, I do have a function that makes a heavy computation in Julia, from \\mathbb R^n to \\mathbb R^m. It uses loops, multiplications, additions, divisions, substractions, powers and exp/log. I am looking to inverse the f…

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## [Separating Numbers from Letters (from anything else) using Regex](https://discourse.julialang.org/t/separating-numbers-from-letters-from-anything-else-using-regex/53613)

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**Author:** [@danilo-bc](https://discourse.julialang.org/u/danilo-bc)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 4:16pm UTC](https://discourse.julialang.org/t/separating-numbers-from-letters-from-anything-else-using-regex/53613 "2021-01-19T16:16:48Z")

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I’m trying to incorporate regular expressions on some of my pattern matching functions, but I’m still having a hard time figuring out how to use them to separate my strings. Starting off easily, I want to separate numbe…

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## [Running Julia on a Personal Linux Server](https://discourse.julialang.org/t/running-julia-on-a-personal-linux-server/53449)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 3\
**Last updated:** [January 19, 2021, 3:07pm UTC](https://discourse.julialang.org/t/running-julia-on-a-personal-linux-server/53449 "2021-01-19T15:07:59Z")

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Hi everyone, I have a personal Linux Server (Raspberry Pi running Rasbpian) and want to have a perpetually running Julia instance going on the server. My rationale behind this is to have the server execute some scripts …

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## [Split boolean array into array for sets of trues and false](https://discourse.julialang.org/t/split-boolean-array-into-array-for-sets-of-trues-and-false/53609)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 3\
**Last updated:** [January 19, 2021, 2:56pm UTC](https://discourse.julialang.org/t/split-boolean-array-into-array-for-sets-of-trues-and-false/53609 "2021-01-19T14:56:01Z")

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Is there a function that does something like this: I have a Boolean array, e.g. input = \[true,true,false,false,false,false,true,true,true,false,false,true\]. I want to get a set of arrays for the corresponding regions of…

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## [Any way to delete an object and free memory?](https://discourse.julialang.org/t/any-way-to-delete-an-object-and-free-memory/53600)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 5\
**Last updated:** [January 19, 2021, 2:19pm UTC](https://discourse.julialang.org/t/any-way-to-delete-an-object-and-free-memory/53600 "2021-01-19T14:19:50Z")

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Hi, I have a Monte Carlo simulation code that uses instances of a mutable struct that contain arrays. These arrays can be really large when the number of particles in the simulation increase. In the code, I have one ins…

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