# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1250

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

**Page:** 1251

---

## [Weighted sampling algorithms not yet shipped?](https://discourse.julialang.org/t/weighted-sampling-algorithms-not-yet-shipped/69111)

<div class="topic-metadata">

**Author:** [@Naba7](https://discourse.julialang.org/u/Naba7)\
**Replies:** 1\
**Last updated:** [October 2, 2021, 12:40pm UTC](https://discourse.julialang.org/t/weighted-sampling-algorithms-not-yet-shipped/69111 "2021-10-02T12:40:39Z")

</div>

Why direct\_sample!, knuths\_sample!, alias\_sample or any of the other Weighted sampling algorithms say they are not defined? Are those functions not yet shipped? direct\_sample!(Random.GLOBAL\_RNG, rand(50), Weights(rand(5…

---

## [3D quiver plot?](https://discourse.julialang.org/t/3d-quiver-plot/69075)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 10\
**Last updated:** [October 2, 2021, 9:06am UTC](https://discourse.julialang.org/t/3d-quiver-plot/69075 "2021-10-02T09:06:05Z")

</div>

Hello! I am aware of the quiver function, but am not sure how to easily do a 3d quiver plot? Kind regards

---

## [How does JuMP.jl (Gurobi solver) take full advantage of the performance of multi-core CPUs](https://discourse.julialang.org/t/how-does-jump-jl-gurobi-solver-take-full-advantage-of-the-performance-of-multi-core-cpus/69103)

<div class="topic-metadata">

**Author:** [@iiitr](https://discourse.julialang.org/u/iiitr)\
**Replies:** 2\
**Last updated:** [October 2, 2021, 11:07am UTC](https://discourse.julialang.org/t/how-does-jump-jl-gurobi-solver-take-full-advantage-of-the-performance-of-multi-core-cpus/69103 "2021-10-02T11:07:24Z")

</div>

Hi all, In the past, I usually used Yalmip to complete the modeling of mathematical optimization. When I construct a large-scale mixed integer linear programming, I don’t need any additional settings, and Gurobi can alw…

---

## [Pkg3 vs. Go's vgo](https://discourse.julialang.org/t/pkg3-vs-gos-vgo/10154)

<div class="topic-metadata">

**Author:** [@waldyrious](https://discourse.julialang.org/u/waldyrious)\
**Replies:** 9\
**Last updated:** [April 17, 2018, 10:06pm UTC](https://discourse.julialang.org/t/pkg3-vs-gos-vgo/10154 "2018-04-17T22:06:07Z")

</div>

The other day I came across the post A Proposal for Package Versioning in Go in Go’s blog, and the following passages in particular (edited for clarity) got me wondering about whether these concerns (and corresponding pr…

---

## [Some clarification on \`@inbounds\`](https://discourse.julialang.org/t/some-clarification-on-inbounds/69076)

<div class="topic-metadata">

**Author:** [@markmbaum](https://discourse.julialang.org/u/markmbaum)\
**Replies:** 2\
**Last updated:** [October 1, 2021, 9:51pm UTC](https://discourse.julialang.org/t/some-clarification-on-inbounds/69076 "2021-10-01T21:51:32Z")

</div>

I know that @inbounds can be applied before a statement like x\[i\] = y and it will elide the bounds check for the setindex! call on x. I’m a little confused about where else @inbounds can be applied, though. If I write …

---

## [Mixed partials](https://discourse.julialang.org/t/mixed-partials/69068)

<div class="topic-metadata">

**Author:** [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Replies:** 1\
**Last updated:** [October 1, 2021, 9:29pm UTC](https://discourse.julialang.org/t/mixed-partials/69068 "2021-10-01T21:29:11Z")

</div>

Suppose that I have a scalar function of multiple variables, e.g., z = f(x,y) How can I compute mixed partials using ForwardDiff? E.g., suppose that I want d^2f/dxdy The case for the hessian, it is clear, e.g., d^2f/…

---

## [Struct: access only one element from it](https://discourse.julialang.org/t/struct-access-only-one-element-from-it/68977)

<div class="topic-metadata">

**Author:** [@flalom](https://discourse.julialang.org/u/flalom)\
**Replies:** 7\
**Last updated:** [October 1, 2021, 9:08pm UTC](https://discourse.julialang.org/t/struct-access-only-one-element-from-it/68977 "2021-10-01T21:08:12Z")

</div>

Hi there! It is not so clear to me how to access a single element of a struct: mutable struct CREDENTIALS PASS::AbstractString USER::AbstractString end I would like to access CREDENTIALS.PASS and assign it to…

---

## [Why are flux models declared in top-level scope?](https://discourse.julialang.org/t/why-are-flux-models-declared-in-top-level-scope/68954)

<div class="topic-metadata">

**Author:** [@htmj](https://discourse.julialang.org/u/htmj)\
**Replies:** 4\
**Last updated:** [October 1, 2021, 8:48pm UTC](https://discourse.julialang.org/t/why-are-flux-models-declared-in-top-level-scope/68954 "2021-10-01T20:48:28Z")

</div>

From what I understand, one of the big things to avoid in julia is to have stuff be in the global scope (at least unless they are declared constant). In addition I don’t understand how i’m supposed to have several “inst…

---

## [Is there anyone that is an expert in SQL?](https://discourse.julialang.org/t/is-there-anyone-that-is-an-expert-in-sql/68766)

<div class="topic-metadata">

**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 8\
**Last updated:** [October 1, 2021, 7:54pm UTC](https://discourse.julialang.org/t/is-there-anyone-that-is-an-expert-in-sql/68766 "2021-10-01T19:54:02Z")

</div>

I was trying to use PostgresSQL in an accounting program, but I couldn’t get it to load. I want to know the best options for relational databases, and how to integrate them into my code.

---

## [Strange symbols show up on using LaTeX tables in Pluto Notebook](https://discourse.julialang.org/t/strange-symbols-show-up-on-using-latex-tables-in-pluto-notebook/69050)

<div class="topic-metadata">

**Author:** [@rodolforbcoutinho](https://discourse.julialang.org/u/rodolforbcoutinho)\
**Replies:** 2\
**Last updated:** [October 1, 2021, 7:46pm UTC](https://discourse.julialang.org/t/strange-symbols-show-up-on-using-latex-tables-in-pluto-notebook/69050 "2021-10-01T19:46:23Z")

</div>

Hi. I’m seen strange symbols on LaTeX tables when they render in Pluto Notebooks. Its just a temporary bug or could I’m making some mistakes? I’m using Chrome Browser. In anex a print from notebook and the code. Best …

---

## [Instability diffeq](https://discourse.julialang.org/t/instability-diffeq/69062)

<div class="topic-metadata">

**Author:** [@Jorge\_Silva](https://discourse.julialang.org/u/Jorge_Silva)\
**Replies:** 1\
**Last updated:** [October 1, 2021, 6:09pm UTC](https://discourse.julialang.org/t/instability-diffeq/69062 "2021-10-01T18:09:26Z")

</div>

I have a system with a dependent mass matrix. It always return me some mensage of instability. Is it an intrisic characteristic of the system? Any thing I can do about? using DifferentialEquations alpha=0.105 …

---

## [How to set max\_iterations for Optim.jl](https://discourse.julialang.org/t/how-to-set-max-iterations-for-optim-jl/61410)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 5\
**Last updated:** [October 1, 2021, 6:04pm UTC](https://discourse.julialang.org/t/how-to-set-max-iterations-for-optim-jl/61410 "2021-10-01T18:04:32Z")

</div>

I have the following code: lower = \[-20, -20, -20, -20, -20, -20.0, -20, -20, -20, -20, -20, -20\] upper = \[ 20, 20, 20, 20, 20, 20.0, 20, 20, 20, 20, 20, 20\] initial\_x = \[-1.4665866297620287, -3.…

---

## [Uploading vector of vectors to GPU in flux.jl](https://discourse.julialang.org/t/uploading-vector-of-vectors-to-gpu-in-flux-jl/68552)

<div class="topic-metadata">

**Author:** [@mys\_721tx](https://discourse.julialang.org/u/mys_721tx)\
**Replies:** 4\
**Last updated:** [October 1, 2021, 5:55pm UTC](https://discourse.julialang.org/t/uploading-vector-of-vectors-to-gpu-in-flux-jl/68552 "2021-10-01T17:55:52Z")

</div>

Hello all, I am training a many-to-many RNN. My input and output data are both Vector{Vector{Vector{Float32}}}. The jld file of the input and output is about 3GB. I checked the model-zoo and did not find anything exampl…

---

## [Unsatisfiable requirements generated by two unrelated local packages](https://discourse.julialang.org/t/unsatisfiable-requirements-generated-by-two-unrelated-local-packages/69052)

<div class="topic-metadata">

**Author:** [@Jack\_Coughlin](https://discourse.julialang.org/u/Jack_Coughlin)\
**Replies:** 2\
**Last updated:** [October 1, 2021, 5:45pm UTC](https://discourse.julialang.org/t/unsatisfiable-requirements-generated-by-two-unrelated-local-packages/69052 "2021-10-01T17:45:13Z")

</div>

I have a pair of local packages that I am working on in parallel, call them LocalA and LocalB. Just now I entered a new REPL and executed \] dev . on LocalA, hoping to use a Revise.jl workflow with it in the REPL. This gi…

---

## [Avoid re-compiling functions with specialized types](https://discourse.julialang.org/t/avoid-re-compiling-functions-with-specialized-types/69057)

<div class="topic-metadata">

**Author:** [@whatsthecraic](https://discourse.julialang.org/u/whatsthecraic)\
**Replies:** 1\
**Last updated:** [October 1, 2021, 5:25pm UTC](https://discourse.julialang.org/t/avoid-re-compiling-functions-with-specialized-types/69057 "2021-10-01T17:25:37Z")

</div>

suppose we have the following classes: struct A; end struct B; end struct C{T}; x; end function foo(c::C); c.x = 1; end does invoking foo(C{A}()) and foo(C{B}()) still cause the compiler to generate two specialized fu…

---

## [Is there a metaprogramming package for struct creation?](https://discourse.julialang.org/t/is-there-a-metaprogramming-package-for-struct-creation/69055)

<div class="topic-metadata">

**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 2\
**Last updated:** [October 1, 2021, 5:02pm UTC](https://discourse.julialang.org/t/is-there-a-metaprogramming-package-for-struct-creation/69055 "2021-10-01T17:02:27Z")

</div>

@flalom and I recently fell into the same beginner trap of setting the fields of a struct to abstract types: Basic struct usage questions - New to Julia - JuliaLang Struct: access only one element from it - New to Juli…

---

## [Julia embedding in a dylib](https://discourse.julialang.org/t/julia-embedding-in-a-dylib/68830)

<div class="topic-metadata">

**Author:** [@gianmariomanca](https://discourse.julialang.org/u/gianmariomanca)\
**Replies:** 3\
**Last updated:** [October 1, 2021, 4:12pm UTC](https://discourse.julialang.org/t/julia-embedding-in-a-dylib/68830 "2021-10-01T16:12:37Z")

</div>

I’m testing a specific case of Embedding Julia · The Julia Language on MacOS. I need to call Julia from a dylib (dylib code in C++) that is called from Julia to pass input data and analyze the results. In other words: …

---

## [Transform counts to binary variable in DataFrame](https://discourse.julialang.org/t/transform-counts-to-binary-variable-in-dataframe/69044)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 5\
**Last updated:** [October 1, 2021, 3:55pm UTC](https://discourse.julialang.org/t/transform-counts-to-binary-variable-in-dataframe/69044 "2021-10-01T15:55:34Z")

</div>

I have a DataFrame containing counts of a binary variable (yes/no). I would like to code the counts as instances of 1 = yes and no = 0. Here is a simple example of the Dataframe with the same structure as my dataset: i…

---

## [\[RFC-ANN\] GeographicModels.jl: earth gravity and magnetic models from GeographicLib](https://discourse.julialang.org/t/rfc-ann-geographicmodels-jl-earth-gravity-and-magnetic-models-from-geographiclib/69021)

<div class="topic-metadata">

**Author:** [@twadleigh](https://discourse.julialang.org/u/twadleigh)\
**Replies:** 1\
**Last updated:** [October 1, 2021, 3:08pm UTC](https://discourse.julialang.org/t/rfc-ann-geographicmodels-jl-earth-gravity-and-magnetic-models-from-geographiclib/69021 "2021-10-01T15:08:32Z")

</div>

I’ve created GeographicModels.jl, a package that wraps the magnetic, gravity, and gridded geoid models of GeographicLib. Possibly useful to persons who want to do high-precision navigation work in julia. I would welcome…

---

## [How to use \`display\` in \`sprint\`?](https://discourse.julialang.org/t/how-to-use-display-in-sprint/69040)

<div class="topic-metadata">

**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 4\
**Last updated:** [October 1, 2021, 2:42pm UTC](https://discourse.julialang.org/t/how-to-use-display-in-sprint/69040 "2021-10-01T14:42:42Z")

</div>

Hi all :slight\_smile: I want to do something like that to get the display string. julia\> display\_str = sprint(display, Dict(1:10 .=\> 1:10)) But it does not work. How would I do that?

---

## [Diagnosing rrule issues](https://discourse.julialang.org/t/diagnosing-rrule-issues/69036)

<div class="topic-metadata">

**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 8\
**Last updated:** [October 1, 2021, 2:24pm UTC](https://discourse.julialang.org/t/diagnosing-rrule-issues/69036 "2021-10-01T14:24:01Z")

</div>

I am using ChainRulesTestUtils to test an rrule for a function mulsafe I define below. The idea is that mulsafe(x,y) returns the product x .\* y, but giving a strong zero if x == 0 (even if y is Inf, or NaN). using Chain…

---

## [Multiple texture interpolations at the same time](https://discourse.julialang.org/t/multiple-texture-interpolations-at-the-same-time/69037)

<div class="topic-metadata">

**Author:** [@lodygaw](https://discourse.julialang.org/u/lodygaw)\
**Replies:** 1\
**Last updated:** [October 1, 2021, 12:07pm UTC](https://discourse.julialang.org/t/multiple-texture-interpolations-at-the-same-time/69037 "2021-10-01T12:07:29Z")

</div>

Hello, I am begginer to Julia and CUDA.jl so please forgive me if the answer to the question is obvious. I couldn’t find the solution by myself. I would like to perform texture interpolation (similar to this) but I hav…

---

## [Change setting of --check-bounds in user code?](https://discourse.julialang.org/t/change-setting-of-check-bounds-in-user-code/69038)

<div class="topic-metadata">

**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 0\
**Last updated:** [October 1, 2021, 11:52am UTC](https://discourse.julialang.org/t/change-setting-of-check-bounds-in-user-code/69038 "2021-10-01T11:52:37Z")

</div>

I’m adding a ‘–debug’ flag to my code, so that users/developers can set an integer ‘debug level’ to run the code with. I’d like one of these levels to force bounds-checking, i.e. behave as if I’d started Julia with --che…

---

## [Local, symbolic sensitivity analysis of Euler Angles](https://discourse.julialang.org/t/local-symbolic-sensitivity-analysis-of-euler-angles/68984)

<div class="topic-metadata">

**Author:** [@JanKap](https://discourse.julialang.org/u/JanKap)\
**Replies:** 6\
**Last updated:** [October 1, 2021, 11:24am UTC](https://discourse.julialang.org/t/local-symbolic-sensitivity-analysis-of-euler-angles/68984 "2021-10-01T11:24:15Z")

</div>

Hey all :slight\_smile: I’m trying to wrap my head around a supposedly simple problem, but it’s not working yet. It is known (see https://www.nxp.com/files-static/sensors/doc/app\_note/AN3461.pdf) that the relationship …

---

## [Makie - Cycle colors for all plots](https://discourse.julialang.org/t/makie-cycle-colors-for-all-plots/69033)

<div class="topic-metadata">

**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 4\
**Last updated:** [October 1, 2021, 11:01am UTC](https://discourse.julialang.org/t/makie-cycle-colors-for-all-plots/69033 "2021-10-01T11:01:11Z")

</div>

Hello! I am trying to substitute the current color cycle by one of my own, but I am not able to do so. I have tried set\_theme!(palette = (color = cgrad(:roma, 4, categorical = true))) and \`Axis(palette = (color = cgrad…

---

## [Package for arbitrary \`getindex\` function?](https://discourse.julialang.org/t/package-for-arbitrary-getindex-function/69034)

<div class="topic-metadata">

**Author:** [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Replies:** 5\
**Last updated:** [October 1, 2021, 10:08am UTC](https://discourse.julialang.org/t/package-for-arbitrary-getindex-function/69034 "2021-10-01T10:08:46Z")

</div>

Does anyone know if we have an array package that lets you specify an arbitrary getindex function? Implementing it is pretty trivial; aside from tests, this is a complete package: module ClosureArrays export ClosureArr…

---

## [Callbacks interfering with solver output](https://discourse.julialang.org/t/callbacks-interfering-with-solver-output/69001)

<div class="topic-metadata">

**Author:** [@arkanver](https://discourse.julialang.org/u/arkanver)\
**Replies:** 2\
**Last updated:** [October 1, 2021, 8:35am UTC](https://discourse.julialang.org/t/callbacks-interfering-with-solver-output/69001 "2021-10-01T08:35:39Z")

</div>

Hello all, I am currently working on a MILP using JuMP and Gurobi. As far as I’m aware my versions are all up to date - Julia 1.6.3, JuMP v0.21.10, Gurobi.jl v0.9.14 (and Gurobi - the solver - 9.1.2). I’m solving my pr…

---

## [Is there an idiomatic way to select a single value from a SQL query?](https://discourse.julialang.org/t/is-there-an-idiomatic-way-to-select-a-single-value-from-a-sql-query/68962)

<div class="topic-metadata">

**Author:** [@gleyland](https://discourse.julialang.org/u/gleyland)\
**Replies:** 3\
**Last updated:** [October 1, 2021, 7:59am UTC](https://discourse.julialang.org/t/is-there-an-idiomatic-way-to-select-a-single-value-from-a-sql-query/68962 "2021-10-01T07:59:23Z")

</div>

Hi, Some SQL queries (like “SELECT COUNT(\*)…”) return a single value. The shortest way I’ve managed to come up with for obtaining the result of the query is: using SQLite db = SQLite.DB() SQLite.DBInterface.execute(db…

---

## [Can I access all of my historical questions in a list?](https://discourse.julialang.org/t/can-i-access-all-of-my-historical-questions-in-a-list/68883)

<div class="topic-metadata">

**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 3\
**Last updated:** [September 28, 2021, 3:58pm UTC](https://discourse.julialang.org/t/can-i-access-all-of-my-historical-questions-in-a-list/68883 "2021-09-28T15:58:34Z")

</div>

One question about using julialang community: Is there a way I can access all of my historical questions in a list? Thanks.

---

## [Error when installing \*some\* packages](https://discourse.julialang.org/t/error-when-installing-some-packages/68994)

<div class="topic-metadata">

**Author:** [@Wjgatt](https://discourse.julialang.org/u/Wjgatt)\
**Replies:** 5\
**Last updated:** [October 1, 2021, 6:23am UTC](https://discourse.julialang.org/t/error-when-installing-some-packages/68994 "2021-10-01T06:23:15Z")

</div>

Hi all, I run into the problem below when I try to install some, but not all, packages on my work PC (i.e. I don’t have admin rights). For example, I get this when trying to install DataVoyager, VegaLite (which is relate…

[Previous page](https://discourse.julialang.org/latest.md?page=1249)

[Next page](https://discourse.julialang.org/latest.md?page=1251)