# Latest

**URL:** https://discourse.julialang.org/latest.md?page=845

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

**Page:** 846

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## [JuliaCon 2023 Call for proposals (CFP) is live!](https://discourse.julialang.org/t/juliacon-2023-call-for-proposals-cfp-is-live/90168)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 1\
**Last updated:** [December 5, 2022, 2:30am UTC](https://discourse.julialang.org/t/juliacon-2023-call-for-proposals-cfp-is-live/90168 "2022-12-05T02:30:00Z")

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Hey all! On behalf of the JuliaCon 2023 Organizing committee, I am excited to share that the 2023 Call for proposals (CFP) is now live: JuliaCon 2023 :: pretalx and will close on January 15th. JuliaCon 2023 will be bac…

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## [Extracting data from netcdf stacked file](https://discourse.julialang.org/t/extracting-data-from-netcdf-stacked-file/90927)

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**Author:** [@lmonteiro](https://discourse.julialang.org/u/lmonteiro)\
**Replies:** 2\
**Last updated:** [November 28, 2022, 3:14am UTC](https://discourse.julialang.org/t/extracting-data-from-netcdf-stacked-file/90927 "2022-11-28T03:14:28Z")

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Hi everybody, I have several nc files from AgERA5 database and I want to do 2 main tasks: 1- stack them in a unique nc file; and 2- extract the data series from a specific pair of lat lon coordinates from the stacked …

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## [\[ANN\] DelaunayTriangulation.jl](https://discourse.julialang.org/t/ann-delaunaytriangulation-jl/91239)

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**Author:** [@DanielVandH](https://discourse.julialang.org/u/DanielVandH)\
**Replies:** 0\
**Last updated:** [December 5, 2022, 1:43am UTC](https://discourse.julialang.org/t/ann-delaunaytriangulation-jl/91239 "2022-12-05T01:43:35Z")

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Hi all, I have just released my package DelaunayTriangulation.jl for computing Delaunay triangulations of points in \\mathbb R^2. The package makes use of the great package ExactPredicates.jl for the geometric predicates…

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## [Registration via Juliahub does not generate github package release](https://discourse.julialang.org/t/registration-via-juliahub-does-not-generate-github-package-release/83728)

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**Author:** [@MartinOtter](https://discourse.julialang.org/u/MartinOtter)\
**Replies:** 4\
**Last updated:** [December 4, 2022, 11:02pm UTC](https://discourse.julialang.org/t/registration-via-juliahub-does-not-generate-github-package-release/83728 "2022-12-04T23:02:09Z")

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Since some time registration in Julia registry is successful, but no release (and no tag) is generated for the package on github. There is always a “Server Error” from github actions: Run JuliaRegistries/TagBot@v1 /usr/…

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## [Preconditioners quite slow in PDE system with DifferentialEquations.jl](https://discourse.julialang.org/t/preconditioners-quite-slow-in-pde-system-with-differentialequations-jl/74926)

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**Author:** [@Iddingsite](https://discourse.julialang.org/u/Iddingsite)\
**Replies:** 6\
**Last updated:** [December 4, 2022, 9:55pm UTC](https://discourse.julialang.org/t/preconditioners-quite-slow-in-pde-system-with-differentialequations-jl/74926 "2022-12-04T21:55:18Z")

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Hi everyone, I am using DifferentialEquations.jl to solve 2 couple non-linear PDEs used to model a two-phase flow in a porous media: \\begin{align} \\frac{\\partial \\phi}{\\partial t} = \\nabla \\cdot \[\\phi^n(\\nabla P + u\_z)…

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## [Error with Julia-Client incompatible with the current version of Atom](https://discourse.julialang.org/t/error-with-julia-client-incompatible-with-the-current-version-of-atom/91229)

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**Author:** [@Jorisboyx](https://discourse.julialang.org/u/Jorisboyx)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 9:52pm UTC](https://discourse.julialang.org/t/error-with-julia-client-incompatible-with-the-current-version-of-atom/91229 "2022-12-04T21:52:08Z")

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I suddenly came across this problem on Mac. Do I need to reinstall julia? I clicked the rebuilt but it failed.

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## [L0 norm in JuMp?](https://discourse.julialang.org/t/l0-norm-in-jump/91222)

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**Author:** [@Gaulex](https://discourse.julialang.org/u/Gaulex)\
**Replies:** 4\
**Last updated:** [December 4, 2022, 9:05pm UTC](https://discourse.julialang.org/t/l0-norm-in-jump/91222 "2022-12-04T21:05:23Z")

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Hello, I would like to minimize the L0-norm of a vector (i.e. the number of non-zero element) using JuMp, but I really struggle to achieve it. I tried to define a function to represent the L0-norm: count\_nonzero(x) = s…

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## [How to create a valid \`FeatureCollection\` I can interface with \`GeoJSON\`?](https://discourse.julialang.org/t/how-to-create-a-valid-featurecollection-i-can-interface-with-geojson/91197)

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**Author:** [@ctrebbau](https://discourse.julialang.org/u/ctrebbau)\
**Replies:** 7\
**Last updated:** [December 4, 2022, 8:11pm UTC](https://discourse.julialang.org/t/how-to-create-a-valid-featurecollection-i-can-interface-with-geojson/91197 "2022-12-04T20:11:00Z")

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using GeoJSON EPS = 5 MAD\_BOUNDS = (40.2257307, 40.6072783, -3.9536568, -3.4525022) grid = Dict("Lat" =\> range(MAD\_BOUNDS\[1\], MAD\_BOUNDS\[2\], EPS), "Lng" =\> range(MAD\_BOUNDS\[3\], MAD\_BOUNDS\[4\], EPS), …

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## [Errors using JuMP with Ipopt or HiGHS: UndefVarError: libipopt not defined and UndefVarError: libhighs not defined](https://discourse.julialang.org/t/errors-using-jump-with-ipopt-or-highs-undefvarerror-libipopt-not-defined-and-undefvarerror-libhighs-not-defined/78539)

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**Author:** [@askvorts](https://discourse.julialang.org/u/askvorts)\
**Replies:** 4\
**Last updated:** [December 4, 2022, 7:48pm UTC](https://discourse.julialang.org/t/errors-using-jump-with-ipopt-or-highs-undefvarerror-libipopt-not-defined-and-undefvarerror-libhighs-not-defined/78539 "2022-12-04T19:48:00Z")

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I have Ipopt, OSQPand HiGHS installed. In Jupiter, when running the following script, n = size(Sigma,1) # Sigma is a 30x30 covariance matrix m = Model(Ipopt.Optimizer) @variable(m, w\[1:n\]) @objective(m, Min, w' …

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## [Cannot convert QuadExpr - error in Julia v1.7 but not v.1.8 with PSDCone()](https://discourse.julialang.org/t/cannot-convert-quadexpr-error-in-julia-v1-7-but-not-v-1-8-with-psdcone/91202)

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**Author:** [@malmassa](https://discourse.julialang.org/u/malmassa)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 7:40pm UTC](https://discourse.julialang.org/t/cannot-convert-quadexpr-error-in-julia-v1-7-but-not-v-1-8-with-psdcone/91202 "2022-12-04T19:40:05Z")

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Hi all, I teach a course on convex optimization and use Julia/JuMP (along with Matlab/CVX) to introduce students to implementation aspects – however, I am not a super-user of Julia/JuMP and may be missing something obvi…

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## [JuMP, GLPK integer decision variable value tolerance](https://discourse.julialang.org/t/jump-glpk-integer-decision-variable-value-tolerance/91218)

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**Author:** [@Gokhan\_Kof](https://discourse.julialang.org/u/Gokhan_Kof)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 7:32pm UTC](https://discourse.julialang.org/t/jump-glpk-integer-decision-variable-value-tolerance/91218 "2022-12-04T19:32:56Z")

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Hi, I was using GLPK within JuMP to solve an integer linear program. The value of the decision variables are close to integer values. I can just round them if they are within an accepted tolerance. However, GLPK optimi…

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## [Should \`reshape\` have an option for row-major order?](https://discourse.julialang.org/t/should-reshape-have-an-option-for-row-major-order/6929)

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**Author:** [@tparker](https://discourse.julialang.org/u/tparker)\
**Replies:** 28\
**Last updated:** [December 4, 2022, 7:10pm UTC](https://discourse.julialang.org/t/should-reshape-have-an-option-for-row-major-order/6929 "2022-12-04T19:10:18Z")

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Currently reshape can only rearrange the raw linearly ordered data into Julia’s default column-major order (or colexicographical order, for higher-dimensional arrays). Would it be worth adding an optional keyword argumen…

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## [Example for Linear Quadratic Gaussion control design](https://discourse.julialang.org/t/example-for-linear-quadratic-gaussion-control-design/11829)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 6:24pm UTC](https://discourse.julialang.org/t/example-for-linear-quadratic-gaussion-control-design/11829 "2022-12-04T18:24:21Z")

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Hello, My colleague and me wrote the following example for LQG design of a speed controller of a DC motor: using ControlSystems """ Example for designing an LQG speed controller for an electrical DC motor. """ # Const…

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## [Automatic Function loading](https://discourse.julialang.org/t/automatic-function-loading/91199)

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**Author:** [@SergeantMike67](https://discourse.julialang.org/u/SergeantMike67)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 5:54pm UTC](https://discourse.julialang.org/t/automatic-function-loading/91199 "2022-12-04T17:54:41Z")

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I have created a function that calculates the time to either numbers or percentages of an insect emergence that fits a Gompertz model almost exactly. What I am curious about is that I find I am using this function quite…

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## [\[ANN\] KalmanFilters.jl](https://discourse.julialang.org/t/ann-kalmanfilters-jl/63700)

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**Author:** [@zsoerenm](https://discourse.julialang.org/u/zsoerenm)\
**Replies:** 5\
**Last updated:** [December 4, 2022, 4:50pm UTC](https://discourse.julialang.org/t/ann-kalmanfilters-jl/63700 "2022-12-04T16:50:16Z")

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I’m pleased to announce KalmanFilters.jl. Currently it supports the following filter types: (Square Root) Kalman Filter ((SR-)KF) (Square Root) Unscented Kalman Filter ((SR-)UKF) (Square Root) Augment Unscented Kalman…

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## [\[ANN\] IUCNRedList.jl](https://discourse.julialang.org/t/ann-iucnredlist-jl/91219)

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**Author:** [@Jose\_Diaz](https://discourse.julialang.org/u/Jose_Diaz)\
**Replies:** 0\
**Last updated:** [December 4, 2022, 3:54pm UTC](https://discourse.julialang.org/t/ann-iucnredlist-jl/91219 "2022-12-04T15:54:16Z")

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If you’re working in biodiversity and conservation, you might find this package useful. This is an API Wrapper for the IUCN Red List of Threatened Species You can find all the documentation here And you can install it…

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## [About three dot in julia vector](https://discourse.julialang.org/t/about-three-dot-in-julia-vector/91216)

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**Author:** [@Xuekui\_wang](https://discourse.julialang.org/u/Xuekui_wang)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 3:13pm UTC](https://discourse.julialang.org/t/about-three-dot-in-julia-vector/91216 "2022-12-04T15:13:14Z")

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I am a newer to julia, and cannot understand the use of three dot although have read some documents. For example as follows: A is two elements vector of (x,y); B is six elements vector of (1,2,3,4,5,6); C is four eleme…

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## [Cygwin mishap with Julia 1.9.0-alpha1 / Plots (dlopen cant open libcairo-2.dll](https://discourse.julialang.org/t/cygwin-mishap-with-julia-1-9-0-alpha1-plots-dlopen-cant-open-libcairo-2-dll/91179)

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**Author:** [@jdad](https://discourse.julialang.org/u/jdad)\
**Replies:** 5\
**Last updated:** [December 4, 2022, 2:10pm UTC](https://discourse.julialang.org/t/cygwin-mishap-with-julia-1-9-0-alpha1-plots-dlopen-cant-open-libcairo-2-dll/91179 "2022-12-04T14:10:50Z")

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I have downloaded julia-1.9.0-alpha1, and in REPL (Terminal) it works OK.\` However, when I try to use it with Plots under Cygwin, Plots does not inits : davidj@vivojdw ~$ julia19 \_ \_ \_ \_(\_)\_ …

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## [How to extract links from HTML](https://discourse.julialang.org/t/how-to-extract-links-from-html/91175)

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**Author:** [@edas](https://discourse.julialang.org/u/edas)\
**Replies:** 2\
**Last updated:** [December 4, 2022, 1:53pm UTC](https://discourse.julialang.org/t/how-to-extract-links-from-html/91175 "2022-12-04T13:53:46Z")

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I want to extract links form HTML using Cascadia using Gumbo using HTTP,AbstractTrees r = HTTP.get("https://example.com/") h = parsehtml(String(r.body)) body = h.root\[2\] link = eachmatch(Selector("a"), body) Result: …

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## [Scipy.signal.convolve in Julia](https://discourse.julialang.org/t/scipy-signal-convolve-in-julia/91140)

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**Author:** [@Resul.Akay](https://discourse.julialang.org/u/Resul.Akay)\
**Replies:** 6\
**Last updated:** [December 4, 2022, 1:02pm UTC](https://discourse.julialang.org/t/scipy-signal-convolve-in-julia/91140 "2022-12-04T13:02:33Z")

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Hi I am looking for an implementation of scipy.signal.convolve. Is there an implementation in Julia? Or convolution Linear Filtering similar to R stats::filter Thanks

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## [ControlSystem - lsim wrong usage](https://discourse.julialang.org/t/controlsystem-lsim-wrong-usage/91207)

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**Author:** [@GottDengDirk](https://discourse.julialang.org/u/GottDengDirk)\
**Replies:** 4\
**Last updated:** [December 4, 2022, 10:00am UTC](https://discourse.julialang.org/t/controlsystem-lsim-wrong-usage/91207 "2022-12-04T10:00:02Z")

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Hallo， using ControlSystems, DataInterpolations, Plots w0=2\*pi D=0.01 Ki=0.12 s = tf(“s”) sys = Kiw0^2/(s^3+2Dw0s^2+w0^2s+Kiw0^2) tsim = 0:0.005:50; tval() = rand(range(0, stop=50, length=10000)) vec = \[tval() f…

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## [Calling a C function from within a Julia program](https://discourse.julialang.org/t/calling-a-c-function-from-within-a-julia-program/63643)

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**Author:** [@mmv](https://discourse.julialang.org/u/mmv)\
**Replies:** 21\
**Last updated:** [December 4, 2022, 9:50am UTC](https://discourse.julialang.org/t/calling-a-c-function-from-within-a-julia-program/63643 "2022-12-04T09:50:33Z")

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Hi! I’m using Julia 1.6.1 on a MacBook Pro and trying to use the MISR-Toolkit library of C functions within Julia programs. This library is maintained by NASA/JPL and available from GitHub at I was able to access func…

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## [How to overload Base.Complex?](https://discourse.julialang.org/t/how-to-overload-base-complex/91128)

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**Author:** [@photor](https://discourse.julialang.org/u/photor)\
**Replies:** 23\
**Last updated:** [December 4, 2022, 9:12am UTC](https://discourse.julialang.org/t/how-to-overload-base-complex/91128 "2022-12-04T09:12:50Z")

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import Base: Complex struct Complex{T} re::T im::T end gives cannot assign a value to variable Base.Complex from module Main Stacktrace: \[1\] top-level scope @ In\[6\]:1 \[2\] eval @ .\\boot.jl:360 \[inlined…

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## [Failed to load module "colorreload-gtk-module" / "window-decorations-gtk-module"](https://discourse.julialang.org/t/failed-to-load-module-colorreload-gtk-module-window-decorations-gtk-module/91118)

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**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 6\
**Last updated:** [December 4, 2022, 8:46am UTC](https://discourse.julialang.org/t/failed-to-load-module-colorreload-gtk-module-window-decorations-gtk-module/91118 "2022-12-04T08:46:25Z")

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I am frustrated, under Ubuntu 22.04 it is not possible to pipe the output of PlotlyJS to the default web-browser. Today I found the advice to edit the Gtk-configuration file settings.ini in the following forum thread: ge…

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## [Creating connection using AMQPClient takes one second](https://discourse.julialang.org/t/creating-connection-using-amqpclient-takes-one-second/91212)

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**Author:** [@JesperMartinsson](https://discourse.julialang.org/u/JesperMartinsson)\
**Replies:** 0\
**Last updated:** [December 4, 2022, 8:13am UTC](https://discourse.julialang.org/t/creating-connection-using-amqpclient-takes-one-second/91212 "2022-12-04T08:13:17Z")

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I’m comparing the AMQPClient in julia vs using pika in python based on the tutorials provided by RabbitMQ. I notice that creating a connection with pika is almost instantaneous: connection = pika.BlockingConnection(pika…

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## [Clang vs CBindingGen](https://discourse.julialang.org/t/clang-vs-cbindinggen/56693)

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**Author:** [@mhinsch](https://discourse.julialang.org/u/mhinsch)\
**Replies:** 29\
**Last updated:** [December 4, 2022, 7:43am UTC](https://discourse.julialang.org/t/clang-vs-cbindinggen/56693 "2022-12-04T07:43:50Z")

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I’m thinking about generating a wrapper for a pure C library (raylib). So far I have found two options for doing that (semi-) automatically: Clang and CBindingGen. Clang seems to be the default option, but while documen…

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## [Julia Activate enviroment fails on cloned git repo](https://discourse.julialang.org/t/julia-activate-enviroment-fails-on-cloned-git-repo/91204)

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**Author:** [@WillHWThompson](https://discourse.julialang.org/u/WillHWThompson)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 4:45am UTC](https://discourse.julialang.org/t/julia-activate-enviroment-fails-on-cloned-git-repo/91204 "2022-12-04T04:45:04Z")

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Hello, I am new to Julia. I have been working on a project stored in a git repo on my local machine. I have now cloned the repo on an HPC to scale up my analysis. My Julia environment and packages all. When I am in the…

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## [Equivalent of "lchoose" function from R?](https://discourse.julialang.org/t/equivalent-of-lchoose-function-from-r/91205)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 7\
**Last updated:** [December 4, 2022, 4:42am UTC](https://discourse.julialang.org/t/equivalent-of-lchoose-function-from-r/91205 "2022-12-04T04:42:20Z")

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In R there’s a function lchoose(a,b) which computes the logarithm of the binomial coefficient or choose(a,b) number (number of ways to choose b items from a set of a). This is the only way to work with really big numbers…

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## [Why \`\`julia -e\`\` does not work on Windows?](https://discourse.julialang.org/t/why-julia-e-does-not-work-on-windows/91195)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 6\
**Last updated:** [December 4, 2022, 2:32am UTC](https://discourse.julialang.org/t/why-julia-e-does-not-work-on-windows/91195 "2022-12-04T02:32:24Z")

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C:\\Users\\joaqu\\zzz\>julia -e "using Pkg; Pkg.activate(".")" ERROR: syntax: invalid identifier name "." Stacktrace: \[1\] top-level scope but no problem on Linux j@Marilu:~/aaa$ julia -e 'using Pkg; Pkg.activate(".");' …

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## [Computation precision with Float](https://discourse.julialang.org/t/computation-precision-with-float/91180)

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**Author:** [@dgagnon](https://discourse.julialang.org/u/dgagnon)\
**Replies:** 8\
**Last updated:** [December 3, 2022, 9:39pm UTC](https://discourse.julialang.org/t/computation-precision-with-float/91180 "2022-12-03T21:39:32Z")

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I see strange behavior for the computation of a very simple formula: julia\> rounding(Float64) RoundingMode{:Nearest}() julia\> p=0.8 0.8 julia\> 1-p 0.19999999999999996 I have the same result with Julia 1.8.0 on Windows1…

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