# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1867

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

**Page:** 1868

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## [Help with strings!](https://discourse.julialang.org/t/help-with-strings/31979)

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**Author:** [@PseudoCodeNerd](https://discourse.julialang.org/u/PseudoCodeNerd)\
**Replies:** 3\
**Last updated:** [December 7, 2019, 6:28pm UTC](https://discourse.julialang.org/t/help-with-strings/31979 "2019-12-07T18:28:59Z")

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Hello there people at Julia ! I’m a high-school student and recently I’ve been stuck with this problem in Julia. I want to get the first characters of the words in a long sentence (after splitting from the blank) and c…

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## [Symbol (Special Characters) in Julia IDE](https://discourse.julialang.org/t/symbol-special-characters-in-julia-ide/31983)

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**Author:** [@Aquaman](https://discourse.julialang.org/u/Aquaman)\
**Replies:** 0\
**Last updated:** [December 7, 2019, 5:49pm UTC](https://discourse.julialang.org/t/symbol-special-characters-in-julia-ide/31983 "2019-12-07T17:49:36Z")

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Hello everybody, I would ask, how can we define symbol input (Special Characters) in Julia IDE, such as JuliaPro? or we have to use julia symbol input (Special Characters) as we use latex ? best regards

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## [How to change =\> to another symbol?](https://discourse.julialang.org/t/how-to-change-to-another-symbol/31981)

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**Author:** [@gevis](https://discourse.julialang.org/u/gevis)\
**Replies:** 2\
**Last updated:** [December 7, 2019, 5:33pm UTC](https://discourse.julialang.org/t/how-to-change-to-another-symbol/31981 "2019-12-07T17:33:18Z")

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Is any way to change =\> as in Dict(“A”=\>1, “B”=\>2) to a single symbol in Julia? For example, to :, →, or |.

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## [Convex.jl : remarkable increase in perf in dev version (0.13.0) compared to v0.12.6, (now as fast as R/CVXR)](https://discourse.julialang.org/t/convex-jl-remarkable-increase-in-perf-in-dev-version-0-13-0-compared-to-v0-12-6-now-as-fast-as-r-cvxr/31966)

<div class="topic-metadata">

**Author:** [@reumle](https://discourse.julialang.org/u/reumle)\
**Replies:** 1\
**Last updated:** [December 7, 2019, 1:02pm UTC](https://discourse.julialang.org/t/convex-jl-remarkable-increase-in-perf-in-dev-version-0-13-0-compared-to-v0-12-6-now-as-fast-as-r-cvxr/31966 "2019-12-07T13:02:13Z")

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The new version performs magnitudes better than its predecessor on the (simple) benchmark described in Convex.jl (+SCS) more than 100\* slower than R counterpart, CVXR + SCS - #8 by reumle. This enables me to try problem…

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## [MCMC of mixture model using Mamba](https://discourse.julialang.org/t/mcmc-of-mixture-model-using-mamba/31125)

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**Author:** [@SSU](https://discourse.julialang.org/u/SSU)\
**Replies:** 8\
**Last updated:** [December 7, 2019, 10:47am UTC](https://discourse.julialang.org/t/mcmc-of-mixture-model-using-mamba/31125 "2019-12-07T10:47:15Z")

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I am trying to fit my experimental data( ~40k circular data, \[-\\pi, +\\pi\], bimodal) with mixture of von mises distribution using Mamba. I want to predict the parameters(\\mu, \\kappa, weights) of the data. Problem The fo…

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## [RCall : how to get values of a R object?](https://discourse.julialang.org/t/rcall-how-to-get-values-of-a-r-object/31925)

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**Author:** [@Fred](https://discourse.julialang.org/u/Fred)\
**Replies:** 4\
**Last updated:** [December 7, 2019, 10:30am UTC](https://discourse.julialang.org/t/rcall-how-to-get-values-of-a-r-object/31925 "2019-12-07T10:30:24Z")

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Hi, Some R functions retrieve many statistical parameters such as pvalue, confidence interval etc… I would like to know how it is possible to extract those parameters from a R object ? For example here how can I get pva…

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## [Custom likelihood with Turing.jl](https://discourse.julialang.org/t/custom-likelihood-with-turing-jl/31471)

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**Author:** [@depasquale](https://discourse.julialang.org/u/depasquale)\
**Replies:** 6\
**Last updated:** [December 7, 2019, 4:34am UTC](https://discourse.julialang.org/t/custom-likelihood-with-turing-jl/31471 "2019-12-07T04:34:53Z")

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Hi all, I’d like to use Turing.jl to sample from a custom likelihood function. I’ve seen this post here and the DynamicHMCexamples.jl package, which gives very nice tutorials for doing this using DynamicHMC, but I would…

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## [Setting the working directory to the directory of current open file as default?](https://discourse.julialang.org/t/setting-the-working-directory-to-the-directory-of-current-open-file-as-default/23089)

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**Author:** [@ahmetumutdurmus](https://discourse.julialang.org/u/ahmetumutdurmus)\
**Replies:** 10\
**Last updated:** [December 7, 2019, 12:31am UTC](https://discourse.julialang.org/t/setting-the-working-directory-to-the-directory-of-current-open-file-as-default/23089 "2019-12-07T00:31:13Z")

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Hello, When I open a Julia file in Atom my working directory is automatically set to my HOME directory. Thus I have to either explicitly code: cd(dirname(@\_\_FILE\_\_)) or use the following command: Julia Client: Work in F…

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## [Juno pyplot doesn't fit 'Plots' window](https://discourse.julialang.org/t/juno-pyplot-doesnt-fit-plots-window/31938)

<div class="topic-metadata">

**Author:** [@sergii](https://discourse.julialang.org/u/sergii)\
**Replies:** 1\
**Last updated:** [December 6, 2019, 8:54pm UTC](https://discourse.julialang.org/t/juno-pyplot-doesnt-fit-plots-window/31938 "2019-12-06T20:54:42Z")

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Please see this screenshot. How to make a plot to fit the window ? It doesn’t happen if I remove pyplot() line or replace it with plotly() . It is not critical now after I learned to use backends other than pypl…

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## [How IntervalSets and UnitRanges compare in functionality?](https://discourse.julialang.org/t/how-intervalsets-and-unitranges-compare-in-functionality/31932)

<div class="topic-metadata">

**Author:** [@sairus7](https://discourse.julialang.org/u/sairus7)\
**Replies:** 1\
**Last updated:** [December 6, 2019, 8:41pm UTC](https://discourse.julialang.org/t/how-intervalsets-and-unitranges-compare-in-functionality/31932 "2019-12-06T20:41:41Z")

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IntervalSets.jl and UnitRanges Both represent some intervals with start – end. Both support operations on sets: in, union, intersect, and so on. UnitRanges define indexing and iterator interface, which is not true sot…

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## [Is there a function to extract the y-channel (=luminance) of an image in julia?](https://discourse.julialang.org/t/is-there-a-function-to-extract-the-y-channel-luminance-of-an-image-in-julia/31936)

<div class="topic-metadata">

**Author:** [@patdax](https://discourse.julialang.org/u/patdax)\
**Replies:** 2\
**Last updated:** [December 6, 2019, 5:40pm UTC](https://discourse.julialang.org/t/is-there-a-function-to-extract-the-y-channel-luminance-of-an-image-in-julia/31936 "2019-12-06T17:40:10Z")

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I am trying to extract the y channel of a rgb image and asking myself if there are some packages available for that?

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## [DiffEqFlux and Flux v0.10 (compatibility)](https://discourse.julialang.org/t/diffeqflux-and-flux-v0-10-compatibility/31921)

<div class="topic-metadata">

**Author:** [@lwhitefox](https://discourse.julialang.org/u/lwhitefox)\
**Replies:** 7\
**Last updated:** [December 6, 2019, 4:14pm UTC](https://discourse.julialang.org/t/diffeqflux-and-flux-v0-10-compatibility/31921 "2019-12-06T16:14:56Z")

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I’d like to grind through the examples at the C. Rackaukas blog post on NN and ODE (DiffEqFlux.jl – A Julia Library for Neural Differential Equations). However, I’m struggling to get packages working together now. If I…

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## [A Julia-Python-R Rosetta Stone](https://discourse.julialang.org/t/a-julia-python-r-rosetta-stone/31917)

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**Author:** [@sswatson](https://discourse.julialang.org/u/sswatson)\
**Replies:** 7\
**Last updated:** [December 6, 2019, 4:05pm UTC](https://discourse.julialang.org/t/a-julia-python-r-rosetta-stone/31917 "2019-12-06T16:05:20Z")

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I’d like to share this cheatsheet illustrating common patterns side by side in Julia, Python, and R. I find it useful as a reference when switching languages, and perhaps others might also find it helpful. Here’s a previ…

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## [Simplifying Distributions type hierarchy](https://discourse.julialang.org/t/simplifying-distributions-type-hierarchy/31882)

<div class="topic-metadata">

**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 14\
**Last updated:** [December 6, 2019, 3:21pm UTC](https://discourse.julialang.org/t/simplifying-distributions-type-hierarchy/31882 "2019-12-06T15:21:56Z")

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In probabilistic programming, we use a a lot of distributions. In some settings, it’s important for it to be very easy to define new distributions, and to reason about them. The current type of a Distribution or Samplea…

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## [Retrieve OnlineStat.Series() statistics](https://discourse.julialang.org/t/retrieve-onlinestat-series-statistics/31901)

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**Author:** [@Dario\_Sarra](https://discourse.julialang.org/u/Dario_Sarra)\
**Replies:** 5\
**Last updated:** [December 6, 2019, 2:22pm UTC](https://discourse.julialang.org/t/retrieve-onlinestat-series-statistics/31901 "2019-12-06T14:22:23Z")

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I can’t understand from the docs how can I retrieve a result from a series. Specifically, if I follow the example y = rand(1000) s = Series(Mean(), Variance()) fit!(s, y) And after I want to apply std() to the resultin…

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## [Sparse matrix pattern?](https://discourse.julialang.org/t/sparse-matrix-pattern/31928)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [December 6, 2019, 11:49am UTC](https://discourse.julialang.org/t/sparse-matrix-pattern/31928 "2019-12-06T11:49:52Z")

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Is there a Plots command similar to MATLAB’s spy command to plot the sparsity pattern of a sparse matrix?

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## [Country Codes](https://discourse.julialang.org/t/country-codes/4010)

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**Author:** [@wibble](https://discourse.julialang.org/u/wibble)\
**Replies:** 6\
**Last updated:** [December 6, 2019, 11:49am UTC](https://discourse.julialang.org/t/country-codes/4010 "2019-12-06T11:49:45Z")

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Hey All, Just wondering if there’s an existing package that would provide a Dict mapping ISO country codes (Alpha-2 or Alpha-3) to country names and possibly ISO numeric codes as well. Thanks!

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## [Setfield! allocates memory when setting Float64 values](https://discourse.julialang.org/t/setfield-allocates-memory-when-setting-float64-values/31811)

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**Author:** [@MartinOtter](https://discourse.julialang.org/u/MartinOtter)\
**Replies:** 4\
**Last updated:** [December 6, 2019, 11:09am UTC](https://discourse.julialang.org/t/setfield-allocates-memory-when-setting-float64-values/31811 "2019-12-06T11:09:28Z")

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The task is to copy all elements of a vector (x::Vector{Float64}) into a hierarchical data structure many times. Hereby the mapping is fixed at the beginning. For example x\[3\] is always copied to a.b.c.d. Intuitively, it…

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## [Memory Usage and SharedArrays](https://discourse.julialang.org/t/memory-usage-and-sharedarrays/31694)

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**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 8\
**Last updated:** [December 6, 2019, 8:02am UTC](https://discourse.julialang.org/t/memory-usage-and-sharedarrays/31694 "2019-12-06T08:02:57Z")

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Hi all, I am new to parallel computing and I had a question regarding memory usage with SharedArrays. I am doing parallel computing to do one operation in each worker and write on a particular slice of an Array. If I a…

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## [CPU/GPU data transfer speed](https://discourse.julialang.org/t/cpu-gpu-data-transfer-speed/31857)

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**Author:** [@oschulz](https://discourse.julialang.org/u/oschulz)\
**Replies:** 12\
**Last updated:** [December 6, 2019, 3:22am UTC](https://discourse.julialang.org/t/cpu-gpu-data-transfer-speed/31857 "2019-12-06T03:22:08Z")

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I’m having trouble pushing data from CPU to GPU memory at a decent rate. With 512 MB of Float32 data julia\> using CuArrays julia\> data = rand(Float32, 134217728); everything is nice and fast once the data is on the G…

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## [I am stuck at "Please Authenticate"](https://discourse.julialang.org/t/i-am-stuck-at-please-authenticate/26313)

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**Author:** [@CUHKSZzxy](https://discourse.julialang.org/u/CUHKSZzxy)\
**Replies:** 7\
**Last updated:** [December 5, 2019, 7:56pm UTC](https://discourse.julialang.org/t/i-am-stuck-at-please-authenticate/26313 "2019-12-05T19:56:01Z")

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I am a macbook user, since the JuliaBox is extremely slow, so I am trying to use the Jupyter notebook based on my own computer. However, when I am running the following code, something went wrong. using Pkg Pkg.add(“Im…

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## [Julia 1.3.0 PDF missing](https://discourse.julialang.org/t/julia-1-3-0-pdf-missing/31773)

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**Author:** [@basko](https://discourse.julialang.org/u/basko)\
**Replies:** 2\
**Last updated:** [December 5, 2019, 7:40pm UTC](https://discourse.julialang.org/t/julia-1-3-0-pdf-missing/31773 "2019-12-05T19:40:32Z")

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The link “https://raw.githubusercontent.com/JuliaLang/docs.julialang.org/assets/julia-1.3.0.pdf” on Julia Documentation · The Julia Language is invalid (404: Not Found). As a newbe to Julia I would like to have the most …

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## [Adjusting Weight and Legends with Plotting](https://discourse.julialang.org/t/adjusting-weight-and-legends-with-plotting/29491)

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**Author:** [@Donald\_Lee](https://discourse.julialang.org/u/Donald_Lee)\
**Replies:** 2\
**Last updated:** [December 5, 2019, 6:11pm UTC](https://discourse.julialang.org/t/adjusting-weight-and-legends-with-plotting/29491 "2019-12-05T18:11:14Z")

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I’m using Plots and Gadfly pkgs to plot. I’d like to know how to make various adjustments, such as making the x and y-labels bold. I’d also like to know how to be able to move the legend within or to outside of the plo…

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## [Linear algebra/algorithm: possible speed up for summing up matrices commutators](https://discourse.julialang.org/t/linear-algebra-algorithm-possible-speed-up-for-summing-up-matrices-commutators/31912)

<div class="topic-metadata">

**Author:** [@Egwene\_al\_Vere](https://discourse.julialang.org/u/Egwene_al_Vere)\
**Replies:** 1\
**Last updated:** [December 5, 2019, 5:52pm UTC](https://discourse.julialang.org/t/linear-algebra-algorithm-possible-speed-up-for-summing-up-matrices-commutators/31912 "2019-12-05T17:52:29Z")

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With matrix commutator \[A,B\] \\equiv AB-BA, consider the sum of \\sum\_{i=1}^k \[MF\_i, F\_{k-i+1}\], where M and F\_{j} are known matrices. I’m using something like this that allocate in advance: using LinearAlgebra using Benc…

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## [Controlling Artifacts download, hash, and environment in 1.3](https://discourse.julialang.org/t/controlling-artifacts-download-hash-and-environment-in-1-3/31868)

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**Author:** [@crinders](https://discourse.julialang.org/u/crinders)\
**Replies:** 9\
**Last updated:** [December 5, 2019, 5:37pm UTC](https://discourse.julialang.org/t/controlling-artifacts-download-hash-and-environment-in-1-3/31868 "2019-12-05T17:37:59Z")

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I compiled release-1.3.1.-pre and ran julia\> \]up with the unsatisfying result: Updating registry at \`~/.julia/registries/General\` Updating git-repo \`https://github.com/JuliaRegistries/General.git\` Resolving packa…

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## [Module loading on workers](https://discourse.julialang.org/t/module-loading-on-workers/31814)

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**Author:** [@pfarndt](https://discourse.julialang.org/u/pfarndt)\
**Replies:** 4\
**Last updated:** [December 5, 2019, 5:34pm UTC](https://discourse.julialang.org/t/module-loading-on-workers/31814 "2019-12-05T17:34:57Z")

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Through some trials and errors I realized that modules, which are loaded with using, are also loaded on the already existing workers. Therefore the following code runs without an error: using Distributed addprocs(2) us…

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## [Switching from Jupyter to a proper IDE](https://discourse.julialang.org/t/switching-from-jupyter-to-a-proper-ide/31648)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 24\
**Last updated:** [December 5, 2019, 5:00pm UTC](https://discourse.julialang.org/t/switching-from-jupyter-to-a-proper-ide/31648 "2019-12-05T17:00:41Z")

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Hi! I’m using JupyterLab for the majority of my work in Julia, and it is definitely lacking in capabilities of IDEs like Juno and Julia plugin for VSCode - like debugging, variable inspection, and so on. Even autoindent …

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## [Cross-platform unpacking of tar archive](https://discourse.julialang.org/t/cross-platform-unpacking-of-tar-archive/31459)

<div class="topic-metadata">

**Author:** [@NiclasMattsson](https://discourse.julialang.org/u/NiclasMattsson)\
**Replies:** 9\
**Last updated:** [December 5, 2019, 4:55pm UTC](https://discourse.julialang.org/t/cross-platform-unpacking-of-tar-archive/31459 "2019-12-05T16:55:17Z")

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I need to unpack uncompressed .tar archives from within Julia and have it work on all platforms. Maybe a clue: there seems to be some code for this here within Pkg.PlatformEngines but I couldn’t figure out how to access…

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## [How to splice two time series into one in a plot?](https://discourse.julialang.org/t/how-to-splice-two-time-series-into-one-in-a-plot/31902)

<div class="topic-metadata">

**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 17\
**Last updated:** [December 5, 2019, 4:33pm UTC](https://discourse.julialang.org/t/how-to-splice-two-time-series-into-one-in-a-plot/31902 "2019-12-05T16:33:44Z")

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Hello, I have two differential equation time series (sol and sol2). sol\[end\] is used as the starting values for sol2. I would like to plot these two on the same plot, if possible, like so. I can graph them separatel…

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## [Optim: gradient and Hessian of constraints](https://discourse.julialang.org/t/optim-gradient-and-hessian-of-constraints/31493)

<div class="topic-metadata">

**Author:** [@Alois](https://discourse.julialang.org/u/Alois)\
**Replies:** 3\
**Last updated:** [December 5, 2019, 3:43pm UTC](https://discourse.julialang.org/t/optim-gradient-and-hessian-of-constraints/31493 "2019-12-05T15:43:57Z")

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Hello, I am using Optim.jl to solve a constrained optimization problem. The gradient is not specified, so finite differences are the default. This works nicely for the objective, but not for the constraints. Thank yo…

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