# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1613

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

**Page:** 1614

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## [I can solve the equations by ode45 in MATLAB, However, failed in julia with Warning: Instability detected. Aborting](https://discourse.julialang.org/t/i-can-solve-the-equations-by-ode45-in-matlab-however-failed-in-julia-with-warning-instability-detected-aborting/47678)

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**Author:** [@Rozarspady](https://discourse.julialang.org/u/Rozarspady)\
**Replies:** 1\
**Last updated:** [October 3, 2020, 12:10pm UTC](https://discourse.julialang.org/t/i-can-solve-the-equations-by-ode45-in-matlab-however-failed-in-julia-with-warning-instability-detected-aborting/47678 "2020-10-03T12:10:34Z")

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i have use the same odefun in both matlab and julia,however, i got a warning in julia,the codes are as follows. I have changed the methods in julia and dimin,maxiters, but failed. using DifferentialEquations u0=\[2.46…

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## [DIffEqFlux loss function with variable solve options](https://discourse.julialang.org/t/diffeqflux-loss-function-with-variable-solve-options/47361)

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**Author:** [@FHell](https://discourse.julialang.org/u/FHell)\
**Replies:** 6\
**Last updated:** [October 3, 2020, 6:42am UTC](https://discourse.julialang.org/t/diffeqflux-loss-function-with-variable-solve-options/47361 "2020-10-03T06:42:02Z")

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Does someone know a good way to pass solve options to a custom loss function? We are building a package and would like to provide a loss function of the DiffEqFlux type, and I would like the user to be able to control th…

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## [Can't access moment\_matrix() function in SumOfSquares](https://discourse.julialang.org/t/cant-access-moment-matrix-function-in-sumofsquares/47624)

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**Author:** [@aliceee](https://discourse.julialang.org/u/aliceee)\
**Replies:** 3\
**Last updated:** [October 3, 2020, 8:25am UTC](https://discourse.julialang.org/t/cant-access-moment-matrix-function-in-sumofsquares/47624 "2020-10-03T08:25:45Z")

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Hi, I’m trying to use the moment\_matrix function in SumOfSquares package. using MultivariateMoments ν3 = moment\_matrix(constr) However, I got the following error: ArgumentError: ModelLike of type MosekModel does not s…

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## [Error in "Don't unroll the adjoint" paper?](https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 1\
**Last updated:** [October 3, 2020, 8:05am UTC](https://discourse.julialang.org/t/error-in-dont-unroll-the-adjoint-paper/47685 "2020-10-03T08:05:31Z")

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Referring to the paper https://arxiv.org/pdf/1810.07951.pdf I see this passage which means it will run into an infinite loop as the end of block#2 goes back to black #2 with no way to exit. I think it’s meant to say…

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## [Weird error with optional arguments](https://discourse.julialang.org/t/weird-error-with-optional-arguments/47684)

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**Author:** [@subramanya\_gautam](https://discourse.julialang.org/u/subramanya_gautam)\
**Replies:** 5\
**Last updated:** [October 3, 2020, 6:58am UTC](https://discourse.julialang.org/t/weird-error-with-optional-arguments/47684 "2020-10-03T06:58:30Z")

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I am pretty new to julia - and I encountered this error when I was trying to implement a code that takes an optional argument that is a dict. So I try function test\_optional(x,y,z=nothing) print("$x,$y") if z!=n…

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## [Can you export plots with the plotly back-end as interactive plots?](https://discourse.julialang.org/t/can-you-export-plots-with-the-plotly-back-end-as-interactive-plots/31377)

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**Author:** [@ElectronicTeaCup](https://discourse.julialang.org/u/ElectronicTeaCup)\
**Replies:** 1\
**Last updated:** [October 3, 2020, 6:35am UTC](https://discourse.julialang.org/t/can-you-export-plots-with-the-plotly-back-end-as-interactive-plots/31377 "2020-10-03T06:35:26Z")

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Suppose I have to share a plot I made using Plots.jl with the plotly back-end. Can I export it in a format that would let a user (without anything Julia related installed) be able to open it and interact it with the way …

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## [Accuracy\_score](https://discourse.julialang.org/t/accuracy-score/47650)

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**Author:** [@Mun\_Barimukh](https://discourse.julialang.org/u/Mun_Barimukh)\
**Replies:** 2\
**Last updated:** [October 3, 2020, 4:27am UTC](https://discourse.julialang.org/t/accuracy-score/47650 "2020-10-03T04:27:12Z")

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How to check the accuracy for linear regression model.

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## [DataFrames.leftjoin now working? leftjoin not defined](https://discourse.julialang.org/t/dataframes-leftjoin-now-working-leftjoin-not-defined/47667)

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**Author:** [@psabela](https://discourse.julialang.org/u/psabela)\
**Replies:** 2\
**Last updated:** [October 3, 2020, 4:06am UTC](https://discourse.julialang.org/t/dataframes-leftjoin-now-working-leftjoin-not-defined/47667 "2020-10-03T04:06:18Z")

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julia\> using DataFrames julia\> jobs = DataFrame(ID = \[20, 60\], Job = \[“Lawyer”, “Astronaut”\]) 2×2 DataFrame │ Row │ ID │ Job │ │ │ Int64 │ String │ ├─────┼───────┼───────────┤ │ 1 │ 20 │ Lawyer…

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## [Iteration using array of arrays/matrices vs iteration over matrix subsets](https://discourse.julialang.org/t/iteration-using-array-of-arrays-matrices-vs-iteration-over-matrix-subsets/47661)

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**Author:** [@jleman](https://discourse.julialang.org/u/jleman)\
**Replies:** 2\
**Last updated:** [October 3, 2020, 12:00am UTC](https://discourse.julialang.org/t/iteration-using-array-of-arrays-matrices-vs-iteration-over-matrix-subsets/47661 "2020-10-03T00:00:15Z")

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It seems to me that in past versions of Julia the array of arrays or array of matrices approach for iteration usually outperformed iterating over matrix subsets. That gap seems to be smaller in the more recent version. …

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## [Is there something equivalent to deparse(substitute(x)) in Julia?](https://discourse.julialang.org/t/is-there-something-equivalent-to-deparse-substitute-x-in-julia/47666)

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**Author:** [@julianjohs](https://discourse.julialang.org/u/julianjohs)\
**Replies:** 1\
**Last updated:** [October 2, 2020, 10:39pm UTC](https://discourse.julialang.org/t/is-there-something-equivalent-to-deparse-substitute-x-in-julia/47666 "2020-10-02T22:39:05Z")

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Dear all, coming from R, I used to use deparse(substitute(x)) to get the name of an object x as a string. Is there anything similar in Julia? Thanks in advance!

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## [Trying to launch Julia cluster under PBS](https://discourse.julialang.org/t/trying-to-launch-julia-cluster-under-pbs/47558)

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**Author:** [@Jeff\_Becker](https://discourse.julialang.org/u/Jeff_Becker)\
**Replies:** 8\
**Last updated:** [October 2, 2020, 9:28pm UTC](https://discourse.julialang.org/t/trying-to-launch-julia-cluster-under-pbs/47558 "2020-10-02T21:28:04Z")

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Hi. I used PBS qsub to get four nodes on our cluster. I put the contents of $PBS\_NODEFILE in the array hosts below. After doing “using Distributed”, I tried using addprocs as below, and I don’t understand what to do abou…

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## [Suggestion needed: Tree like structure for adaptive binning of multidim data](https://discourse.julialang.org/t/suggestion-needed-tree-like-structure-for-adaptive-binning-of-multidim-data/47602)

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**Author:** [@francesco.alemanno](https://discourse.julialang.org/u/francesco.alemanno)\
**Replies:** 6\
**Last updated:** [October 2, 2020, 9:01pm UTC](https://discourse.julialang.org/t/suggestion-needed-tree-like-structure-for-adaptive-binning-of-multidim-data/47602 "2020-10-02T21:01:52Z")

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Hi everyone, i need to perform adaptive binning of multidimensional data, in an online fashion. as far as i understand i need a dynamic kd-tree, is there something in the julia ecosystem that implements a structure re…

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## [No REPL in Atom anymore](https://discourse.julialang.org/t/no-repl-in-atom-anymore/47653)

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**Author:** [@ulipoto](https://discourse.julialang.org/u/ulipoto)\
**Replies:** 2\
**Last updated:** [October 2, 2020, 7:36pm UTC](https://discourse.julialang.org/t/no-repl-in-atom-anymore/47653 "2020-10-02T19:36:53Z")

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Hey guys! I have been using Julia on Atom for a while now. This week I had to run a C shell file, therefore I installed ubuntu and followed a tutorial kinda blind to give it some permissions (I know, stupid). Now, when…

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## [State of JuAFEM](https://discourse.julialang.org/t/state-of-juafem/39183)

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**Author:** [@CorbinFoucart](https://discourse.julialang.org/u/CorbinFoucart)\
**Replies:** 2\
**Last updated:** [October 2, 2020, 6:17pm UTC](https://discourse.julialang.org/t/state-of-juafem/39183 "2020-10-02T18:17:09Z")

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I’m reading the JuAFEM dev docs and it’s not immediately apparent whether a few things are supported. Are: general unstructured grids (tet, hex) wedge elements nonconforming and adaptive meshes supported? Secondly, i…

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## [How do you get debugger to work in current environment in VsCode](https://discourse.julialang.org/t/how-do-you-get-debugger-to-work-in-current-environment-in-vscode/47659)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 0\
**Last updated:** [October 2, 2020, 6:16pm UTC](https://discourse.julialang.org/t/how-do-you-get-debugger-to-work-in-current-environment-in-vscode/47659 "2020-10-02T18:16:00Z")

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I cannot find the documentation on setting an active environment for the debugger. It doesn’t appear to use the active environment set in the REPL. Instead it goes back to the default for the Julia version @1.5. That …

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## [Hierarchical Component Models in ModelingToolkit, How to Connect](https://discourse.julialang.org/t/hierarchical-component-models-in-modelingtoolkit-how-to-connect/47626)

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**Author:** [@mefob](https://discourse.julialang.org/u/mefob)\
**Replies:** 2\
**Last updated:** [October 2, 2020, 5:20pm UTC](https://discourse.julialang.org/t/hierarchical-component-models-in-modelingtoolkit-how-to-connect/47626 "2020-10-02T17:20:49Z")

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I am trying to build a hierarchical model of groups of Lorenz oscillators. I am following the tutorial, but instead of solving the pair of coupled oscillators, I’d like to solve a set of many pairs of coupled oscillators…

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## [Are Python packages called in julia faster than in python](https://discourse.julialang.org/t/are-python-packages-called-in-julia-faster-than-in-python/47644)

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**Author:** [@MalteMederacke](https://discourse.julialang.org/u/MalteMederacke)\
**Replies:** 12\
**Last updated:** [October 2, 2020, 5:04pm UTC](https://discourse.julialang.org/t/are-python-packages-called-in-julia-faster-than-in-python/47644 "2020-10-02T17:04:10Z")

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Hi guys, basicly this. I am not a computer scientist, but I am curious, if I call a python package with julia, does it run faster than in python? Or is it the same or even slower.

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## [CUDA.jl 2.0: Per-thread streams, Float16, CUSPARSE clean-up](https://discourse.julialang.org/t/cuda-jl-2-0-per-thread-streams-float16-cusparse-clean-up/47630)

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**Author:** [@maleadt](https://discourse.julialang.org/u/maleadt)\
**Replies:** 2\
**Last updated:** [October 2, 2020, 4:46pm UTC](https://discourse.julialang.org/t/cuda-jl-2-0-per-thread-streams-float16-cusparse-clean-up/47630 "2020-10-02T16:46:16Z")

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Hi all, I’ve just tagged and release CUDA.jl 2.0, with several new features: https://juliagpu.org/2020-10-02-cuda\_2.0/ This release is slightly breaking because of the following changes: per-thread streams: unlikely …

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## [Flux vs pytorch cpu performance](https://discourse.julialang.org/t/flux-vs-pytorch-cpu-performance/42667)

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**Author:** [@d1cker](https://discourse.julialang.org/u/d1cker)\
**Replies:** 59\
**Last updated:** [October 2, 2020, 3:39pm UTC](https://discourse.julialang.org/t/flux-vs-pytorch-cpu-performance/42667 "2020-10-02T15:39:07Z")

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Hi, I’m trying to make my colleagues use Julia, but I got this performance issue with some simple code. At first I though that the problem is use the AD but now I think it’s with the feed forward (and because of that th…

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## [Two questions on Flux](https://discourse.julialang.org/t/two-questions-on-flux/22307)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 23\
**Last updated:** [October 2, 2020, 3:28pm UTC](https://discourse.julialang.org/t/two-questions-on-flux/22307 "2020-10-02T15:28:35Z")

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I’ve watched videos in JuliaAcademy (I recommend them), and continued playing around with Flux. To test Flux, I’ve tried to re-create simple results from: Bishop, Chris M. (1994). “Neural networks and their application…

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## [How to time julia's choleskey factorization?](https://discourse.julialang.org/t/how-to-time-julias-choleskey-factorization/47627)

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**Author:** [@vkv](https://discourse.julialang.org/u/vkv)\
**Replies:** 8\
**Last updated:** [October 2, 2020, 2:44pm UTC](https://discourse.julialang.org/t/how-to-time-julias-choleskey-factorization/47627 "2020-10-02T14:44:03Z")

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Hi, I’m trying to compare timings of julia’s cholesky factorization and LAPACK.potrf! function. The timings of julia’s cholesky function is varying from 50 \\mu s to 100 \\mu s and LAPACK.potrf! is blazingly fast varying…

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## [The JuliaDebug repo: how to be helpful to newbies (and old hands as well)?](https://discourse.julialang.org/t/the-juliadebug-repo-how-to-be-helpful-to-newbies-and-old-hands-as-well/47618)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 12\
**Last updated:** [October 2, 2020, 2:39pm UTC](https://discourse.julialang.org/t/the-juliadebug-repo-how-to-be-helpful-to-newbies-and-old-hands-as-well/47618 "2020-10-02T14:39:01Z")

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When one visits JuliaDebug, the page shows about a dozen repos but no guidance as to what does what, what is live, and how to make sense of it all. I don’t have a good answer yet, but how about you all?

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## [Pgfplotsx, plots: non-uniform colormaps only partially implemented](https://discourse.julialang.org/t/pgfplotsx-plots-non-uniform-colormaps-only-partially-implemented/47621)

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**Author:** [@AntoninDellaNoce](https://discourse.julialang.org/u/AntoninDellaNoce)\
**Replies:** 15\
**Last updated:** [October 2, 2020, 2:16pm UTC](https://discourse.julialang.org/t/pgfplotsx-plots-non-uniform-colormaps-only-partially-implemented/47621 "2020-10-02T14:16:40Z")

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Hi, I have an error at the level of pgfplots package when using pgfplotsx() backend to draw surfaces. Here is the working example provided by the Plots documentation surface(range(-3,3, length=30), range(-3,3, length=3…

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## [Random number generators](https://discourse.julialang.org/t/random-number-generators/47613)

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**Author:** [@caetanotc](https://discourse.julialang.org/u/caetanotc)\
**Replies:** 3\
**Last updated:** [October 2, 2020, 1:28pm UTC](https://discourse.julialang.org/t/random-number-generators/47613 "2020-10-02T13:28:41Z")

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Hi, I’m new to julia and have some questions about RNG’s. If I understood well, MersenneTwister is the default method, but MersenneTwister objects are linked with the Random library and rand() function isn’t. When usin…

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## [Integration of function with discontinuities given as vector elements with "quadgk"?](https://discourse.julialang.org/t/integration-of-function-with-discontinuities-given-as-vector-elements-with-quadgk/47629)

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**Author:** [@hainzl](https://discourse.julialang.org/u/hainzl)\
**Replies:** 3\
**Last updated:** [October 2, 2020, 1:21pm UTC](https://discourse.julialang.org/t/integration-of-function-with-discontinuities-given-as-vector-elements-with-quadgk/47629 "2020-10-02T13:21:32Z")

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I want to integrate a function f, which has discontinuities at the positions given as vector elements x\[i\] (the length of the vector and its values depends on the particular data set). I know the “quadgk” offers the pos…

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## [Is there some minimal list of packages (almost) all users should use?](https://discourse.julialang.org/t/is-there-some-minimal-list-of-packages-almost-all-users-should-use/47583)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 7\
**Last updated:** [October 2, 2020, 12:19pm UTC](https://discourse.julialang.org/t/is-there-some-minimal-list-of-packages-almost-all-users-should-use/47583 "2020-10-02T12:19:29Z")

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I do see e.g. brand new ConcreateStructs.jl but it may be too new, so I have established packages in mind at least. I’m not thinking of e.g. some statistics package, but to add language features (and well Revise.jl), no…

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## [The current state of Javis and a look into the future](https://discourse.julialang.org/t/the-current-state-of-javis-and-a-look-into-the-future/47631)

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**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\
**Replies:** 0\
**Last updated:** [October 2, 2020, 9:45am UTC](https://discourse.julialang.org/t/the-current-state-of-javis-and-a-look-into-the-future/47631 "2020-10-02T09:45:46Z")

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Javis is a relatively new Julia package which helps you to create animations in general. Ranging from making a simple loading animation to a fourier animation (thanks @ric.cioffi) In my newest blog post you can read ab…

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## [Pkg\> dev --local /some/path doesn't make a local clone in ./dev](https://discourse.julialang.org/t/pkg-dev-local-some-path-doesnt-make-a-local-clone-in-dev/47316)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 5\
**Last updated:** [October 2, 2020, 9:08am UTC](https://discourse.julialang.org/t/pkg-dev-local-some-path-doesnt-make-a-local-clone-in-dev/47316 "2020-10-02T09:08:05Z")

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I am trying to use pkg\> dev --local for a package available locally, but it seems that --local is ignored and no copy in dev is made. Is this expected behavior or a known issue? dev --local works for registered packages…

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## [Using optim.jl - how can i set an interval for x\[1\] , for example](https://discourse.julialang.org/t/using-optim-jl-how-can-i-set-an-interval-for-x-1-for-example/6949)

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**Author:** [@leaoshark](https://discourse.julialang.org/u/leaoshark)\
**Replies:** 9\
**Last updated:** [October 2, 2020, 7:33am UTC](https://discourse.julialang.org/t/using-optim-jl-how-can-i-set-an-interval-for-x-1-for-example/6949 "2020-10-02T07:33:38Z")

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Hello. using optim.jl in julia ( using ATOM ide ) opt = optimize(function, \[starting\_guess\] ) suposse my starting guess is \[ 1 ; 2 \] for x\[1\] and x\[2\] … the program will find the best x\[1\] and x\[2\] to fit my data … …

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## [VegaLite, "description" doesn't work](https://discourse.julialang.org/t/vegalite-description-doesnt-work/47625)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 1\
**Last updated:** [October 2, 2020, 7:19am UTC](https://discourse.julialang.org/t/vegalite-description-doesnt-work/47625 "2020-10-02T07:19:48Z")

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Would you help me? How can I add a title to a figure? I’ve tried “description” - it didn’t work. Thank you in advance.

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