# Latest

**URL:** https://discourse.julialang.org/latest.md?page=702

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

**Page:** 703

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## [Cfunction error handler](https://discourse.julialang.org/t/cfunction-error-handler/20678)

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**Author:** [@Bernard\_GODARD](https://discourse.julialang.org/u/Bernard_GODARD)\
**Replies:** 3\
**Last updated:** [May 12, 2023, 7:49am UTC](https://discourse.julialang.org/t/cfunction-error-handler/20678 "2023-05-12T07:49:02Z")

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Hi I am trying to wrap a C function to set a error handler in the CALCEPH C library. The prototype is: void calceph\_seterrorhandler(int typehandler, void (\*userfunc)(const char\*)) The error message is passed to userfu…

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## [How to specify weights (wts) in MixedModels.jl?](https://discourse.julialang.org/t/how-to-specify-weights-wts-in-mixedmodels-jl/98707)

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**Author:** [@Rscho314](https://discourse.julialang.org/u/Rscho314)\
**Replies:** 0\
**Last updated:** [May 11, 2023, 11:22pm UTC](https://discourse.julialang.org/t/how-to-specify-weights-wts-in-mixedmodels-jl/98707 "2023-05-11T23:22:44Z")

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Hi, I specified a multilevel longitudinal model in MixedModels.jl. I am having a heteroscedasticity issue, for which I’d like to try to weight observations. So, the unweighted model: fit(MixedModel,@formula(maxtrop~1+…

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## [Needing to plot streaming vehicle trajectories on a map similar to city or road map](https://discourse.julialang.org/t/needing-to-plot-streaming-vehicle-trajectories-on-a-map-similar-to-city-or-road-map/98705)

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**Author:** [@benibilme](https://discourse.julialang.org/u/benibilme)\
**Replies:** 1\
**Last updated:** [May 12, 2023, 7:19am UTC](https://discourse.julialang.org/t/needing-to-plot-streaming-vehicle-trajectories-on-a-map-similar-to-city-or-road-map/98705 "2023-05-12T07:19:47Z")

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Hello, I desparately need a plotting library, platform to plot streaming vehicle trajectories on a city map. I am trying to put distance to python ecosystem and try to stay in julia ecosystem as much as possible but I h…

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## [How to check symmetry inside tuples and avoide overwrtting?](https://discourse.julialang.org/t/how-to-check-symmetry-inside-tuples-and-avoide-overwrtting/98694)

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**Author:** [@Optimization](https://discourse.julialang.org/u/Optimization)\
**Replies:** 6\
**Last updated:** [May 12, 2023, 6:52am UTC](https://discourse.julialang.org/t/how-to-check-symmetry-inside-tuples-and-avoide-overwrtting/98694 "2023-05-12T06:52:50Z")

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Is there any easy way to check if you have symmetric tuples in your lists? Like auto checking that \[(2,3),(3,5),(3,2),..., \[10,8)\] has. Because of (2,3) and (3,2). Also I don’r have any tuples with same number as first…

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## [How can I just use the return value from one function but without calling that function in Julia](https://discourse.julialang.org/t/how-can-i-just-use-the-return-value-from-one-function-but-without-calling-that-function-in-julia/98708)

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**Author:** [@jianqixi](https://discourse.julialang.org/u/jianqixi)\
**Replies:** 2\
**Last updated:** [May 12, 2023, 12:10am UTC](https://discourse.julialang.org/t/how-can-i-just-use-the-return-value-from-one-function-but-without-calling-that-function-in-julia/98708 "2023-05-12T00:10:46Z")

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I know it maybe weird to ask this kind of question, but I am not sure Julia has this kind of way to achieve what I want. Here is one example code: function initialize(a,b,c) do something return x end function run(a,…

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## [Plotting trajectories](https://discourse.julialang.org/t/plotting-trajectories/7111)

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**Author:** [@Romero\_Azzalini](https://discourse.julialang.org/u/Romero_Azzalini)\
**Replies:** 3\
**Last updated:** [May 11, 2023, 10:41pm UTC](https://discourse.julialang.org/t/plotting-trajectories/7111 "2023-05-11T22:41:46Z")

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Hi, I wanted to plot trajectories around a planet and therefore cut out a circle in the middle of the plot (PyPlot). I tried it with fill, but I can still see the trajectories :frowning: Also I want to plot 3D trajec…

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## [Working with Multiple Vectors of Parameters](https://discourse.julialang.org/t/working-with-multiple-vectors-of-parameters/98685)

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**Author:** [@astrobc1](https://discourse.julialang.org/u/astrobc1)\
**Replies:** 2\
**Last updated:** [May 11, 2023, 8:37pm UTC](https://discourse.julialang.org/t/working-with-multiple-vectors-of-parameters/98685 "2023-05-11T20:37:33Z")

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I’m working with the SciML Optimization framework trying to optimize several Vectors of parameters with ReverseDiff.jl. I understand the Vector that’s passed to my objective function is flattened, so I’m also passing the…

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## ["julia: error while loading shared libraries: libjulia.so.1: cannot open shared object file: No such file or directory" error when starting julia from command line on ubuntu](https://discourse.julialang.org/t/julia-error-while-loading-shared-libraries-libjulia-so-1-cannot-open-shared-object-file-no-such-file-or-directory-error-when-starting-julia-from-command-line-on-ubuntu/72707)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 4\
**Last updated:** [May 11, 2023, 8:06pm UTC](https://discourse.julialang.org/t/julia-error-while-loading-shared-libraries-libjulia-so-1-cannot-open-shared-object-file-no-such-file-or-directory-error-when-starting-julia-from-command-line-on-ubuntu/72707 "2023-05-11T20:06:27Z")

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On ubuntu 18.04 I have a desktop which I haven’t really used since pre-pandemic times (with julia 1.3.1). I can run julia 1.3.1 from it just fine. However, I want to run the latest version (1.7.0)! I have downloaded tha…

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## [V1.9-rc3 - faster precompilation with explicit \`precompile\` call?](https://discourse.julialang.org/t/v1-9-rc3-faster-precompilation-with-explicit-precompile-call/98323)

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**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 16\
**Last updated:** [May 11, 2023, 6:07pm UTC](https://discourse.julialang.org/t/v1-9-rc3-faster-precompilation-with-explicit-precompile-call/98323 "2023-05-11T18:07:34Z")

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I have an internal package I’m using that is particularly slow to load on 1.9-rc3, on an AWS docker image (built locally, then deployed). Basically it’s just there to bring in all dependencies with some coordinating func…

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## [\[ANN\] FresnelEquations.jl](https://discourse.julialang.org/t/ann-fresnelequations-jl/98693)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 2\
**Last updated:** [May 11, 2023, 5:54pm UTC](https://discourse.julialang.org/t/ann-fresnelequations-jl/98693 "2023-05-11T17:54:03Z")

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I am pleased to announce another minor package of mine that should hit the general registry in a couple of days: :tada: FresnelEquations.jl :tada: After having implemented the rather long and tedious Fresnel equations s…

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## [Question on Starting Julia with Sys Image](https://discourse.julialang.org/t/question-on-starting-julia-with-sys-image/98686)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 1\
**Last updated:** [May 11, 2023, 5:51pm UTC](https://discourse.julialang.org/t/question-on-starting-julia-with-sys-image/98686 "2023-05-11T17:51:03Z")

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I’ve created a system image following the example described here for OhMyREPL. I can now do the following, and it works! julia --sysimage=OMR-sysimage.so But typing that every time is a bit cumbersome. Can loading th…

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## [Saving arguments or wrap function?](https://discourse.julialang.org/t/saving-arguments-or-wrap-function/98688)

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**Author:** [@Veenty](https://discourse.julialang.org/u/Veenty)\
**Replies:** 4\
**Last updated:** [May 11, 2023, 5:42pm UTC](https://discourse.julialang.org/t/saving-arguments-or-wrap-function/98688 "2023-05-11T17:42:41Z")

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Currently I have a structure where I save functions into something of the sort struct fooS x::Float64 A::Dict{Symbol, Function} fooS(x) = new(consfoo(x)...) end function consfoo(x) return x, Dict{Sym…

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## [Logging: filter packages](https://discourse.julialang.org/t/logging-filter-packages/98692)

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**Author:** [@FedeClaudi](https://discourse.julialang.org/u/FedeClaudi)\
**Replies:** 1\
**Last updated:** [May 11, 2023, 5:23pm UTC](https://discourse.julialang.org/t/logging-filter-packages/98692 "2023-05-11T17:23:43Z")

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Hey folks, A quick question: I’ve set the logging level so that I can see @debug messages from my package as I develop stuff. However this will naturally also show @debug messages from other packages that are called fro…

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## [VSCode Run Multiple Lines from File in Terminal Broken](https://discourse.julialang.org/t/vscode-run-multiple-lines-from-file-in-terminal-broken/94796)

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**Author:** [@mrufsvold](https://discourse.julialang.org/u/mrufsvold)\
**Replies:** 6\
**Last updated:** [May 11, 2023, 4:44pm UTC](https://discourse.julialang.org/t/vscode-run-multiple-lines-from-file-in-terminal-broken/94796 "2023-05-11T16:44:56Z")

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EDITED: I was able to narrow down the problem a bit. I recently updated Julia to v1.9.0-beta4. Previously I was on v1.8.2. I have been using v1.41.1 Pre-Release of the Julia VSCode extension. After updating Julia versi…

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## [Flux Dense Layer Type Instability](https://discourse.julialang.org/t/flux-dense-layer-type-instability/98642)

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**Author:** [@Ian\_L](https://discourse.julialang.org/u/Ian_L)\
**Replies:** 7\
**Last updated:** [May 11, 2023, 4:20pm UTC](https://discourse.julialang.org/t/flux-dense-layer-type-instability/98642 "2023-05-11T16:20:12Z")

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Hi. I am stumped as to why the forward pass is type unstable. It’s effectively a varying length chain similar to Flux.Chain on an alternating sequence of dense and dropout layers: struct MLP dense::Vector{Flux.Dense…

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## [Cannot declare constant it already has a value](https://discourse.julialang.org/t/cannot-declare-constant-it-already-has-a-value/77372)

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**Author:** [@the\_dude](https://discourse.julialang.org/u/the_dude)\
**Replies:** 7\
**Last updated:** [May 11, 2023, 4:16pm UTC](https://discourse.julialang.org/t/cannot-declare-constant-it-already-has-a-value/77372 "2023-05-11T16:16:20Z")

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I used this struct I created a lot of times, but now, out of nothing, my VSCode started presenting this: Any idea of what is happening?

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## [Matplotlib & Julia : Pcolormesh and mask](https://discourse.julialang.org/t/matplotlib-julia-pcolormesh-and-mask/1792)

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**Author:** [@lcambier](https://discourse.julialang.org/u/lcambier)\
**Replies:** 2\
**Last updated:** [May 11, 2023, 3:55pm UTC](https://discourse.julialang.org/t/matplotlib-julia-pcolormesh-and-mask/1792 "2023-05-11T15:55:48Z")

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Hi, I have a 2d matrix with values that I currently plot doing something like axis\[:pcolormesh\](A', vmin=minimum(A\[:\]), vmax=0, edgecolor="white") But some values in A are non-relevant and I’d like to give them a whit…

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## [VSCode plots wont show anymore anywhere](https://discourse.julialang.org/t/vscode-plots-wont-show-anymore-anywhere/73470)

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**Author:** [@Wingmore](https://discourse.julialang.org/u/Wingmore)\
**Replies:** 17\
**Last updated:** [May 11, 2023, 3:48pm UTC](https://discourse.julialang.org/t/vscode-plots-wont-show-anymore-anywhere/73470 "2023-05-11T15:48:10Z")

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I have had no issues with VSCode plots until all of a sudden, they stopped showing up. I dont even know what I changed because no matter what I do, the plots dont show up whatsoever. I’m using PlotlyJS, and a simple lin…

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## [Index elements of a function with several outputs](https://discourse.julialang.org/t/index-elements-of-a-function-with-several-outputs/98684)

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**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 3\
**Last updated:** [May 11, 2023, 3:08pm UTC](https://discourse.julialang.org/t/index-elements-of-a-function-with-several-outputs/98684 "2023-05-11T15:08:51Z")

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I would like to access specific output elements of a function. Here an example: function foo() return 1, 2, 3, 4, 5 end If I am only interested in output two and four I can use the underscore: \_, output2, \_, outp…

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## [Work around for \`eigvals!(Matrix{Dec64})\`?](https://discourse.julialang.org/t/work-around-for-eigvals-matrix-dec64/98680)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 2\
**Last updated:** [May 11, 2023, 2:30pm UTC](https://discourse.julialang.org/t/work-around-for-eigvals-matrix-dec64/98680 "2023-05-11T14:30:54Z")

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Reading the code for eigvals!, it always tries to promote the matrix to some kind of “normal” float so it can work with LAPACK.geevx!… I think. But that clearly defeats the purpose of using something like DecFP. julia\> …

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## [Problems with \`dlopen\`](https://discourse.julialang.org/t/problems-with-dlopen/98679)

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**Author:** [@frylock](https://discourse.julialang.org/u/frylock)\
**Replies:** 10\
**Last updated:** [May 11, 2023, 2:27pm UTC](https://discourse.julialang.org/t/problems-with-dlopen/98679 "2023-05-11T14:27:05Z")

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Ok I realize that dlopen may not be a new-to-Julia issue, but FFI is important for us to be able to expand usage of Julia in my company. I have read through the manual section on using C and Fortran (which is rather good…

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## [Why the allocated memory keep increase in for loop](https://discourse.julialang.org/t/why-the-allocated-memory-keep-increase-in-for-loop/98683)

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**Author:** [@crazyfireji](https://discourse.julialang.org/u/crazyfireji)\
**Replies:** 0\
**Last updated:** [May 11, 2023, 1:55pm UTC](https://discourse.julialang.org/t/why-the-allocated-memory-keep-increase-in-for-loop/98683 "2023-05-11T13:55:48Z")

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steps = 799500:100:800000 print("样本数为：",length(steps),"\\n") function main(filepath, nx, ny, nz, steps, Axi, Axj, Ayi, Ayj) hx = 1.0/(nx - 1); hy = 1/(ny - 1); for n in steps print("读取$(n)步 \\n") …

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## [DataFrames: convert column data type](https://discourse.julialang.org/t/dataframes-convert-column-data-type/35522)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 65\
**Last updated:** [May 11, 2023, 1:37pm UTC](https://discourse.julialang.org/t/dataframes-convert-column-data-type/35522 "2023-05-11T13:37:19Z")

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Was looking around, but didn’t find an answer. Specifically, I have a DataFrame and one column has data type Int64; it has the unique values 0 and 1 (meaning obviously false and true). What is the easiest quickest way t…

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## [Load pkg in startup, then activate environment](https://discourse.julialang.org/t/load-pkg-in-startup-then-activate-environment/98671)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 1\
**Last updated:** [May 11, 2023, 12:20pm UTC](https://discourse.julialang.org/t/load-pkg-in-startup-then-activate-environment/98671 "2023-05-11T12:20:22Z")

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What happens if a launch julia, load a package, and then activate a new enviroment?

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## [Turing autodiff error](https://discourse.julialang.org/t/turing-autodiff-error/98603)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 4\
**Last updated:** [May 11, 2023, 12:15pm UTC](https://discourse.julialang.org/t/turing-autodiff-error/98603 "2023-05-11T12:15:00Z")

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I have a two small model which are connected to each other. Both have common parameters. nested task error: TaskFailedException nested task error: MethodError: no method matching Float64(::ForwardDiff.Dual{ForwardDiff.T…

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## [Parse an array of bits (\`BitArray\`) to an integer](https://discourse.julialang.org/t/parse-an-array-of-bits-bitarray-to-an-integer/42361)

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**Author:** [@roi.holtzman](https://discourse.julialang.org/u/roi.holtzman)\
**Replies:** 27\
**Last updated:** [May 11, 2023, 11:52am UTC](https://discourse.julialang.org/t/parse-an-array-of-bits-bitarray-to-an-integer/42361 "2023-05-11T11:52:44Z")

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I want to parse an array of bits to a decimal number. I am using this function now but it does not work very fast function bitarr\_to\_int(arr) return sum(arr .\* (2 .^ collect(length(arr)-1:-1:0))) end Is there a wa…

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## [Error "POOCollSolution not defined" (DDEBifurcationKit)](https://discourse.julialang.org/t/error-poocollsolution-not-defined-ddebifurcationkit/98420)

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**Author:** [@catchia](https://discourse.julialang.org/u/catchia)\
**Replies:** 3\
**Last updated:** [May 11, 2023, 11:45am UTC](https://discourse.julialang.org/t/error-poocollsolution-not-defined-ddebifurcationkit/98420 "2023-05-11T11:45:17Z")

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Hello there. I am new to numerical analysis and Julia, and I intend to perform a bifurcation analysis on a two-component DDE system. (Thanks for the DDEBifurcationKit package @rveltz!) As a start I attempt to reproduce…

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## [How to convert a number to an hexadecimal \`bitstring\`?](https://discourse.julialang.org/t/how-to-convert-a-number-to-an-hexadecimal-bitstring/98673)

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**Author:** [@tokujin](https://discourse.julialang.org/u/tokujin)\
**Replies:** 3\
**Last updated:** [May 11, 2023, 11:27am UTC](https://discourse.julialang.org/t/how-to-convert-a-number-to-an-hexadecimal-bitstring/98673 "2023-05-11T11:27:11Z")

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I can do string(parse(Int, bitstring(x), base=2), base=16) to convert bitstring(x) to an hexadecimal string, but is there another way, one which is simpler and doesn’t trim the leading zeros off of integers?

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## [Trying to implement Miller's recurrence algorithm and getting terrible results](https://discourse.julialang.org/t/trying-to-implement-millers-recurrence-algorithm-and-getting-terrible-results/98574)

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**Author:** [@fda-tome](https://discourse.julialang.org/u/fda-tome)\
**Replies:** 6\
**Last updated:** [May 11, 2023, 11:07am UTC](https://discourse.julialang.org/t/trying-to-implement-millers-recurrence-algorithm-and-getting-terrible-results/98574 "2023-05-11T11:07:08Z")

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I am currently trying to implement Miller’s algorithm but Im getting terrible numerical results, numerical errors are getting to 80% of original values. Is there an issue with my code? function besselj(orderLim, arg::Bi…

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## [Variable rate jump stops matching birth-death theory](https://discourse.julialang.org/t/variable-rate-jump-stops-matching-birth-death-theory/98609)

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**Author:** [@freddie090](https://discourse.julialang.org/u/freddie090)\
**Replies:** 2\
**Last updated:** [May 11, 2023, 11:06am UTC](https://discourse.julialang.org/t/variable-rate-jump-stops-matching-birth-death-theory/98609 "2023-05-11T11:06:37Z")

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I saw that a mixed birth-death ODE-jump process I was using wasn’t behaving as expected. Following some investigation, it appears that when I switch the rates from being ‘ConstantRateJump’ to ‘VariableRateJump’ the birt…

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