# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1160

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

**Page:** 1161

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## [How make a true distributed program](https://discourse.julialang.org/t/how-make-a-true-distributed-program/73919)

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**Author:** [@GalloLuigi](https://discourse.julialang.org/u/GalloLuigi)\
**Replies:** 5\
**Last updated:** [January 5, 2022, 4:18pm UTC](https://discourse.julialang.org/t/how-make-a-true-distributed-program/73919 "2022-01-05T16:18:31Z")

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Hi on my local machine i have a program like this : using Distributed @distributed for(...) # some code end I want to “distribute” the for iterations to some remote virtual machines. How can I do it?

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## [Vector of structs -- push/append/?](https://discourse.julialang.org/t/vector-of-structs-push-append/74092)

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**Author:** [@das](https://discourse.julialang.org/u/das)\
**Replies:** 2\
**Last updated:** [January 5, 2022, 4:11pm UTC](https://discourse.julialang.org/t/vector-of-structs-push-append/74092 "2022-01-05T16:11:37Z")

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I’m trying to create and load a music note (a struct “Note”) into an array representing 16 tracks of music. The declaration: sequence = Note works perfectly and I’ve been able to add notes to sequence by using: push!(se…

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## [Can pluto handle real time data from python code](https://discourse.julialang.org/t/can-pluto-handle-real-time-data-from-python-code/73838)

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**Author:** [@anon69491625](https://discourse.julialang.org/u/anon69491625)\
**Replies:** 6\
**Last updated:** [January 5, 2022, 4:01pm UTC](https://discourse.julialang.org/t/can-pluto-handle-real-time-data-from-python-code/73838 "2022-01-05T16:01:08Z")

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I am working on my first julia program and using an existing python script I wrote to give me a data stream. To develop I am using Pluto and PyCall and trying to implement a asynch callback that returns a stream of data…

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## [How to use/add local temporary dependencies?](https://discourse.julialang.org/t/how-to-use-add-local-temporary-dependencies/74091)

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**Author:** [@Sushant-Padha](https://discourse.julialang.org/u/Sushant-Padha)\
**Replies:** 1\
**Last updated:** [January 5, 2022, 3:57pm UTC](https://discourse.julialang.org/t/how-to-use-add-local-temporary-dependencies/74091 "2022-01-05T15:57:26Z")

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I am creating a package in Julia. For that package environment, I have also \] added the Revise and OhMyREPL packages, for convenience. However, when I upload my package to the general registry, I don’t really want to ke…

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## [Error while parallelizing](https://discourse.julialang.org/t/error-while-parallelizing/74049)

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**Author:** [@Sumit\_Malbari](https://discourse.julialang.org/u/Sumit_Malbari)\
**Replies:** 0\
**Last updated:** [January 4, 2022, 5:43pm UTC](https://discourse.julialang.org/t/error-while-parallelizing/74049 "2022-01-04T17:43:30Z")

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Hi All, I ran JULIA\_COPY\_STACKS=yes julia -e ‘using Pkg;Pkg.add(Pkg.PackageSpec(;name=“Spark”, version=“0.5.1”));Pkg.build(“Spark”);using Spark;Spark.init();sc = SparkContext(master=“yarn”);’ all this worked fine. C…

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## [How to add CUDA as optional dependency?](https://discourse.julialang.org/t/how-to-add-cuda-as-optional-dependency/73077)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 19\
**Last updated:** [January 5, 2022, 3:44pm UTC](https://discourse.julialang.org/t/how-to-add-cuda-as-optional-dependency/73077 "2022-01-05T15:44:46Z")

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Suppose I have a package and that I am interested in providing an option to end users to speed up their calculations in the presence of a NVIDIA GPU. Not everyone will benefit from this option and so I can’t add CUDA as …

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## [Putting offline some old doc where Google is still sending](https://discourse.julialang.org/t/putting-offline-some-old-doc-where-google-is-still-sending/73955)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [January 5, 2022, 3:35pm UTC](https://discourse.julialang.org/t/putting-offline-some-old-doc-where-google-is-still-sending/73955 "2022-01-05T15:35:05Z")

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urgh… Google for some queries still sends to these pages… https://kristofferc.github.io/JuliaDocFrontPageEx That, if you are directly directed to an inner page (e.g. https://kristofferc.github.io/JuliaDocFrontPageEx/st…

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## [What is the best way to keyboard macros in Julia/VSCode?](https://discourse.julialang.org/t/what-is-the-best-way-to-keyboard-macros-in-julia-vscode/74081)

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**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 2\
**Last updated:** [January 5, 2022, 12:03pm UTC](https://discourse.julialang.org/t/what-is-the-best-way-to-keyboard-macros-in-julia-vscode/74081 "2022-01-05T12:03:40Z")

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I use Autohotkey to create keyboard macros (bindings) that can be quite useful. They do not seem to work inside the Visual Studio Code editor. The same key binding that works inside, say, Notepad, does not have any effec…

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## [Embedding Julia in C++: DLL procedure entry point errors](https://discourse.julialang.org/t/embedding-julia-in-c-dll-procedure-entry-point-errors/73792)

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**Author:** [@Thorgrif](https://discourse.julialang.org/u/Thorgrif)\
**Replies:** 4\
**Last updated:** [January 5, 2022, 2:49pm UTC](https://discourse.julialang.org/t/embedding-julia-in-c-dll-procedure-entry-point-errors/73792 "2022-01-05T14:49:30Z")

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Good afternoon, I’ve been trying to follow the basic guide for embedding Julia in C++, and I’m running into a problem when my C++ uses certain standard functions. Here’s a simple bit of test code that causes the prob…

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## [\[ANN\] Skans.jl: Get notified when a web page has changed](https://discourse.julialang.org/t/ann-skans-jl-get-notified-when-a-web-page-has-changed/74086)

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**Author:** [@rikh](https://discourse.julialang.org/u/rikh)\
**Replies:** 1\
**Last updated:** [January 5, 2022, 2:06pm UTC](https://discourse.julialang.org/t/ann-skans-jl-get-notified-when-a-web-page-has-changed/74086 "2022-01-05T14:06:46Z")

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To keep track of things, web pages are often the primary source of information. Twitter bots and journalist base much of their news on updated web pages. For example, organizations and businesses update their web pages w…

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## [What makes a worker terminate on a cluster?](https://discourse.julialang.org/t/what-makes-a-worker-terminate-on-a-cluster/61409)

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**Author:** [@WouterJRV](https://discourse.julialang.org/u/WouterJRV)\
**Replies:** 16\
**Last updated:** [January 5, 2022, 2:02pm UTC](https://discourse.julialang.org/t/what-makes-a-worker-terminate-on-a-cluster/61409 "2022-01-05T14:02:12Z")

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Hi, I am using the Julia language for calculations on a cluster. Typically, I define a few sharedarrays in the beginning of a script, and then do a @sync @distributed for over say 32 cores of a node to fill it (mainly u…

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## [LightGraphs.jl/Graphs.jl only values from half the cartesian plane is needed](https://discourse.julialang.org/t/lightgraphs-jl-graphs-jl-only-values-from-half-the-cartesian-plane-is-needed/74080)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 3\
**Last updated:** [January 5, 2022, 1:34pm UTC](https://discourse.julialang.org/t/lightgraphs-jl-graphs-jl-only-values-from-half-the-cartesian-plane-is-needed/74080 "2022-01-05T13:34:50Z")

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Hi, this is a continuation of finding link distances between species in a food web. It’s been a few months so I am starting a new topic. I can find distances between species, but when I want to randomly choose a species …

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## [DataFrame grouped by a column; How to access a group by a particular value in that column](https://discourse.julialang.org/t/dataframe-grouped-by-a-column-how-to-access-a-group-by-a-particular-value-in-that-column/74084)

<div class="topic-metadata">

**Author:** [@empet](https://discourse.julialang.org/u/empet)\
**Replies:** 1\
**Last updated:** [January 5, 2022, 12:41pm UTC](https://discourse.julialang.org/t/dataframe-grouped-by-a-column-how-to-access-a-group-by-a-particular-value-in-that-column/74084 "2022-01-05T12:41:59Z")

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It’s the first time when I’m working with groupby a DataFrame. Let us say I have a DataFrame, grouped by city name: df=DataFrame(city=\["Paris", "London", "Paris", "Berlin", "London", "Berlin", "Berlin"\], …

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## [Pkg error: identity of github.com could not be verified](https://discourse.julialang.org/t/pkg-error-identity-of-github-com-could-not-be-verified/74079)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 4\
**Last updated:** [January 5, 2022, 12:28pm UTC](https://discourse.julialang.org/t/pkg-error-identity-of-github-com-could-not-be-verified/74079 "2022-01-05T12:28:04Z")

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I am having an issue after installing julia 1.7.1 on Ubuntu using Jill.py that Pkg updates result in an error: (@v1.7) pkg\> update Updating registry at \`~/.julia/registries/General\` Updating git-repo \`https://gi…

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## [Flux.jl Restrict Gradients to Non-Zero values in sparse layer](https://discourse.julialang.org/t/flux-jl-restrict-gradients-to-non-zero-values-in-sparse-layer/72124)

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**Author:** [@james-a-mcmanus](https://discourse.julialang.org/u/james-a-mcmanus)\
**Replies:** 5\
**Last updated:** [January 5, 2022, 11:07am UTC](https://discourse.julialang.org/t/flux-jl-restrict-gradients-to-non-zero-values-in-sparse-layer/72124 "2022-01-05T11:07:06Z")

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Hi, I’m trying to make a custom network layer with sparse weights. I only want to train the non-zero values of the layer, however when I try to create a gradient from this the gradient returns nothing. Here is a MWE. u…

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## [How do I find out about all the (very) specific functions in julia?](https://discourse.julialang.org/t/how-do-i-find-out-about-all-the-very-specific-functions-in-julia/74010)

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**Author:** [@jonoke](https://discourse.julialang.org/u/jonoke)\
**Replies:** 7\
**Last updated:** [January 5, 2022, 10:29am UTC](https://discourse.julialang.org/t/how-do-i-find-out-about-all-the-very-specific-functions-in-julia/74010 "2022-01-05T10:29:59Z")

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Hi, I’m working my way through exercism, and looking at community solutions I’m seeing all these very specific functions that I’m coding myself, eg findall Where should I look to see all the functions julia is providin…

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## [Missing records in my FASTA file when writing new FASTAs](https://discourse.julialang.org/t/missing-records-in-my-fasta-file-when-writing-new-fastas/74032)

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**Author:** [@Lamma](https://discourse.julialang.org/u/Lamma)\
**Replies:** 3\
**Last updated:** [January 5, 2022, 10:27am UTC](https://discourse.julialang.org/t/missing-records-in-my-fasta-file-when-writing-new-fastas/74032 "2022-01-05T10:27:36Z")

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I have a co-assembly and some alignment data telling me if a reads from a sample that helped spawn that co-assembly align to a contig. I am using this to write a fasta file for that sample. t1 = Threads.@spawn DataF…

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## [Is this the maximum perf i can obtain?](https://discourse.julialang.org/t/is-this-the-maximum-perf-i-can-obtain/74022)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 10\
**Last updated:** [January 5, 2022, 9:55am UTC](https://discourse.julialang.org/t/is-this-the-maximum-perf-i-can-obtain/74022 "2022-01-05T09:55:25Z")

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Hi, I have a simple operation to make, which represents 80% of my runtime. I am trying to make it as fast as possible… Here is the sketch of the problem : using Statistics, BenchmarkTools function exp\_and\_mean!(slack,D…

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## [SciMLCon 2022: Call for Reviewers!](https://discourse.julialang.org/t/scimlcon-2022-call-for-reviewers/73937)

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**Author:** [@Renee\_Spear](https://discourse.julialang.org/u/Renee_Spear)\
**Replies:** 1\
**Last updated:** [January 3, 2022, 2:24am UTC](https://discourse.julialang.org/t/scimlcon-2022-call-for-reviewers/73937 "2022-01-03T02:24:12Z")

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SciMLCon 2022 Call for Reviewers Proposals for SciMLCon 2022 are reviewed anonymously by volunteers. A set of proposal abstracts will be assigned to these volunteers who read, rank, and provide feedback/comments on the …

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## [Convert symbol to expression](https://discourse.julialang.org/t/convert-symbol-to-expression/74016)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 5\
**Last updated:** [January 5, 2022, 6:52am UTC](https://discourse.julialang.org/t/convert-symbol-to-expression/74016 "2022-01-05T06:52:15Z")

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I’m trying to complete a DataFrame that omits some years with the average of adjacent years. For example: using DataFrames df = DataFrame(year = \[1995, 1996, 1997, 1999, 2001\], x = float(1:5)) From that, I am trying t…

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## [Precompilation error for CSV package - PosLen not defined](https://discourse.julialang.org/t/precompilation-error-for-csv-package-poslen-not-defined/68480)

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**Author:** [@gobs](https://discourse.julialang.org/u/gobs)\
**Replies:** 7\
**Last updated:** [January 5, 2022, 2:08am UTC](https://discourse.julialang.org/t/precompilation-error-for-csv-package-poslen-not-defined/68480 "2022-01-05T02:08:58Z")

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I have spent about an hour trying to fix a precompilation error related to the CSV package (full stacktrace at bottom). As far as I can tell: Deleting the compiled folder doesn’t help. Neither does starting a new envi…

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## [JuMP constraint: how to use more than one filter elements in the sets](https://discourse.julialang.org/t/jump-constraint-how-to-use-more-than-one-filter-elements-in-the-sets/73928)

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**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 2\
**Last updated:** [January 5, 2022, 12:53am UTC](https://discourse.julialang.org/t/jump-constraint-how-to-use-more-than-one-filter-elements-in-the-sets/73928 "2022-01-05T00:53:39Z")

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Hi, In JuMP, I need to implement a constraint that uses more than one filter elements in the sets. It seems that JuMP accepts only one filter. The error message is:“There can be at most one filtering condition, which i…

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## [JuMP, one constraint with two inequalities in the expression, is it possible?](https://discourse.julialang.org/t/jump-one-constraint-with-two-inequalities-in-the-expression-is-it-possible/73843)

<div class="topic-metadata">

**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 4\
**Last updated:** [January 5, 2022, 12:52am UTC](https://discourse.julialang.org/t/jump-one-constraint-with-two-inequalities-in-the-expression-is-it-possible/73843 "2022-01-05T00:52:45Z")

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Hi, I am having trouble to implement the following constraint (with two inequalities). Does JuMP accept this kind of expression? @constraint(model, con4\[i in Vtotal, j in Vcustomer; i != j\], x\[i,j\] \* Menergy\[i,j\] - (1-x…

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## [Extremely slow CSV / IO?](https://discourse.julialang.org/t/extremely-slow-csv-io/74065)

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**Author:** [@g2boojum](https://discourse.julialang.org/u/g2boojum)\
**Replies:** 3\
**Last updated:** [January 5, 2022, 12:18am UTC](https://discourse.julialang.org/t/extremely-slow-csv-io/74065 "2022-01-05T00:18:16Z")

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The following very simple code takes about 25 seconds to run: using CSV #pulseit = CSV.Rows("Data\_CH0@DT5790N\_13963\_run\_192.csv") pulseit = CSV.Rows("foo.csv") (curr\_pulse, pulse\_state) = iterate(pulseit) (next\_pulse, …

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## [Root finding package with array of polynomials?](https://discourse.julialang.org/t/root-finding-package-with-array-of-polynomials/74061)

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**Author:** [@DeepQ](https://discourse.julialang.org/u/DeepQ)\
**Replies:** 1\
**Last updated:** [January 4, 2022, 9:37pm UTC](https://discourse.julialang.org/t/root-finding-package-with-array-of-polynomials/74061 "2022-01-04T21:37:37Z")

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I have a function defined like: f(x) = a\_1x^2+a\_2x+a\_3 I know that I can find its roots using Roots.jl package. How can I find its roots if its coefficients are a (3,n) matrix instead of just 3 numbers? The matrix is d…

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## [Telethon like library for Julia](https://discourse.julialang.org/t/telethon-like-library-for-julia/74055)

<div class="topic-metadata">

**Author:** [@serhii](https://discourse.julialang.org/u/serhii)\
**Replies:** 4\
**Last updated:** [January 4, 2022, 8:59pm UTC](https://discourse.julialang.org/t/telethon-like-library-for-julia/74055 "2022-01-04T20:59:18Z")

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Hi! I am looking for a library similar to python’s telethon. A quick google search has not led to anything, so I would appreciate your suggestions. I want to emphasize that I am not looking for Telegram Bot API impleme…

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## [Julia 1.8 feature freeze: February 15, 2022](https://discourse.julialang.org/t/julia-1-8-feature-freeze-february-15-2022/74059)

<div class="topic-metadata">

**Author:** [@dilumaluthge](https://discourse.julialang.org/u/dilumaluthge)\
**Replies:** 0\
**Last updated:** [January 4, 2022, 8:56pm UTC](https://discourse.julialang.org/t/julia-1-8-feature-freeze-february-15-2022/74059 "2022-01-04T20:56:50Z")

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We’ve set the feature freeze date for Julia 1.8 to Tuesday, February 15, 2022. If there are any feature PRs you’d like to get into Julia 1.8, they’ll need to be in prior to that date.

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## [TCAD and julia?](https://discourse.julialang.org/t/tcad-and-julia/49590)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 3\
**Last updated:** [January 4, 2022, 8:38pm UTC](https://discourse.julialang.org/t/tcad-and-julia/49590 "2022-01-04T20:38:05Z")

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Is there a package which can solve drift-diffusion and Poisson’s equations for isotype heterojunctions? I think 1D would be enough. I am asking as I would be interested in understanding thermal emission or tunneling tra…

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## [Best way to locate and load a font?](https://discourse.julialang.org/t/best-way-to-locate-and-load-a-font/73996)

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**Author:** [@ederag](https://discourse.julialang.org/u/ederag)\
**Replies:** 7\
**Last updated:** [January 4, 2022, 8:27pm UTC](https://discourse.julialang.org/t/best-way-to-locate-and-load-a-font/73996 "2022-01-04T20:27:02Z")

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After filing https://github.com/JuliaGraphics/FreeTypeAbstraction.jl/issues/67 I have been looking for the best way to locate and load a font. (initially for DynamicGrids.jl, which is otherwise super fast, so it matte…

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## [ERROR: LoadError: Unable to locate Gurobi installation](https://discourse.julialang.org/t/error-loaderror-unable-to-locate-gurobi-installation/74051)

<div class="topic-metadata">

**Author:** [@konsath](https://discourse.julialang.org/u/konsath)\
**Replies:** 2\
**Last updated:** [January 4, 2022, 8:09pm UTC](https://discourse.julialang.org/t/error-loaderror-unable-to-locate-gurobi-installation/74051 "2022-01-04T20:09:50Z")

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I’m using Julia 1.6.5 and Gurobi 9.5.0 but right now Julia is adding an outdated version of Gurobi that doesn’t match my Path (9.5.0). Could anyone provide some insight maybe? :slight\_smile: ‘’’ julia\> Pkg.build(“Gurob…

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