# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1870

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

**Page:** 1871

---

## [Convert delayed differential equation in Julia notation for DifferentialEquations.jl](https://discourse.julialang.org/t/convert-delayed-differential-equation-in-julia-notation-for-differentialequations-jl/31690)

<div class="topic-metadata">

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 6\
**Last updated:** [December 3, 2019, 11:31am UTC](https://discourse.julialang.org/t/convert-delayed-differential-equation-in-julia-notation-for-differentialequations-jl/31690 "2019-12-03T11:31:09Z")

</div>

Hello I am trying to convert the following delayed differential equations (DDE) into Julia notation: Thus I wrote this code followingthis example: using DifferentialEquations function dynDelay!(du, u, h, p) μ, κ,…

---

## [Can't start Julia from folder with Russian characters](https://discourse.julialang.org/t/cant-start-julia-from-folder-with-russian-characters/31792)

<div class="topic-metadata">

**Author:** [@junxz](https://discourse.julialang.org/u/junxz)\
**Replies:** 0\
**Last updated:** [December 3, 2019, 11:14am UTC](https://discourse.julialang.org/t/cant-start-julia-from-folder-with-russian-characters/31792 "2019-12-03T11:14:24Z")

</div>

I’m having problem starting Julia kernel from the folder with Russian characters in it. I get the following error: Please advise how to fix this.

---

## [DimensionMismatch("column length of 178 for columns startTime, startLoc, routePlaned, and is incompatible with column length 177 for columns dists and travelTimes" in julia dataframes)](https://discourse.julialang.org/t/dimensionmismatch-column-length-of-178-for-columns-starttime-startloc-routeplaned-and-is-incompatible-with-column-length-177-for-columns-dists-and-traveltimes-in-julia-dataframes/31759)

<div class="topic-metadata">

**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 5\
**Last updated:** [December 3, 2019, 9:16am UTC](https://discourse.julialang.org/t/dimensionmismatch-column-length-of-178-for-columns-starttime-startloc-routeplaned-and-is-incompatible-with-column-length-177-for-columns-dists-and-traveltimes-in-julia-dataframes/31759 "2019-12-03T09:16:58Z")

</div>

Hi. I was trying to use a dataframe with several columns, where some columns are vectors of varying length; i.e., in some columns, they are of length say 10, and in some other columns, they are of length say 12. Also, i…

---

## [Directory tracking in emacs julia-repl](https://discourse.julialang.org/t/directory-tracking-in-emacs-julia-repl/31770)

<div class="topic-metadata">

**Author:** [@recri](https://discourse.julialang.org/u/recri)\
**Replies:** 1\
**Last updated:** [December 3, 2019, 8:51am UTC](https://discourse.julialang.org/t/directory-tracking-in-emacs-julia-repl/31770 "2019-12-03T08:51:53Z")

</div>

The following snippet for .julia/config/startup.jl implements directory, user, and host tracking for julia-repl. # set up emacs directory, host, and user tracking for julia-repl atreplinit() do repl if haskey(ENV, "…

---

## [Why the result from Flux.jl is totally different from tf.Keras (with the same simple MLP)](https://discourse.julialang.org/t/why-the-result-from-flux-jl-is-totally-different-from-tf-keras-with-the-same-simple-mlp/31739)

<div class="topic-metadata">

**Author:** [@Carol](https://discourse.julialang.org/u/Carol)\
**Replies:** 6\
**Last updated:** [December 3, 2019, 5:26am UTC](https://discourse.julialang.org/t/why-the-result-from-flux-jl-is-totally-different-from-tf-keras-with-the-same-simple-mlp/31739 "2019-12-03T05:26:04Z")

</div>

Dear all, I want to use Flux.jl to build a simple Multi-Layer Perceptron (MLP) as I did in Keras, where the input data is a matrix of nGene (number of genes) by nInd (number of individuals), output data is a vector of l…

---

## [How to implement MLJ models properly for \`learning\_curve!\`](https://discourse.julialang.org/t/how-to-implement-mlj-models-properly-for-learning-curve/31655)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 2\
**Last updated:** [December 3, 2019, 4:34am UTC](https://discourse.julialang.org/t/how-to-implement-mlj-models-properly-for-learning-curve/31655 "2019-12-03T04:34:42Z")

</div>

I am trying to copy the XGBoost.jl with Crabs tutorial with JLBoost.jl. I think the data is identical and most things work fine, but I can’t get learning\_curve! to work. Here is the code. using Pkg; Pkg.activate(".") u…

---

## [Scattered interpolation](https://discourse.julialang.org/t/scattered-interpolation/31733)

<div class="topic-metadata">

**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 5\
**Last updated:** [December 3, 2019, 1:37am UTC](https://discourse.julialang.org/t/scattered-interpolation/31733 "2019-12-03T01:37:54Z")

</div>

Hi, I am kind of struggling with scattered interpolation in Julia for 2D. What I have is a bunch of points (x,y,w), where x and y are coordinates and w is the value. I want to interpolate onto a regular grid. Currently …

---

## [Which Discourse area for PRE Coding discussions? NB I have NOT written a line of code](https://discourse.julialang.org/t/which-discourse-area-for-pre-coding-discussions-nb-i-have-not-written-a-line-of-code/31767)

<div class="topic-metadata">

**Author:** [@anon97116444](https://discourse.julialang.org/u/anon97116444)\
**Replies:** 4\
**Last updated:** [December 2, 2019, 11:43pm UTC](https://discourse.julialang.org/t/which-discourse-area-for-pre-coding-discussions-nb-i-have-not-written-a-line-of-code/31767 "2019-12-02T23:43:34Z")

</div>

HI there, I am trying to make sure I play by the rules of discourse and so far have screwed up TWICE. So, I am making sure that I get it right this time by asking the question in the subject. To clarify, I have a HIGH …

---

## [Trojan horse types - a type that takes over the function calling it](https://discourse.julialang.org/t/trojan-horse-types-a-type-that-takes-over-the-function-calling-it/31731)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 20\
**Last updated:** [December 2, 2019, 11:16pm UTC](https://discourse.julialang.org/t/trojan-horse-types-a-type-that-takes-over-the-function-calling-it/31731 "2019-12-02T23:16:03Z")

</div>

I have been implementing a new type of array which is just a normal array except the content is fetched in the background and everything about it is the same as a normal array including access etc. I call this Array the…

---

## [How can I use TileDB from Julia?](https://discourse.julialang.org/t/how-can-i-use-tiledb-from-julia/18864)

<div class="topic-metadata">

**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 6\
**Last updated:** [November 18, 2019, 9:16pm UTC](https://discourse.julialang.org/t/how-can-i-use-tiledb-from-julia/18864 "2019-11-18T21:16:14Z")

</div>

How can I use TileDB from Julia? Is there any port? I’ve searched on Julia observer but haven’t find anything? I’ve also searched on JuliaDB docs but haven’t found anything. I’m looking for a fast database to deal with…

---

## [Completely puzzled why AdvancedHMC version went backwards](https://discourse.julialang.org/t/completely-puzzled-why-advancedhmc-version-went-backwards/31729)

<div class="topic-metadata">

**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 4\
**Last updated:** [December 2, 2019, 9:01pm UTC](https://discourse.julialang.org/t/completely-puzzled-why-advancedhmc-version-went-backwards/31729 "2019-12-02T21:01:09Z")

</div>

Today I perform update on the packages for Julia-1.3 But I was extremely puzzled why the package AdvancedHMC version went BACKWARDS. No other package version has went backwards. Updating \`~/.julia/environments/v1.3/Pro…

---

## [Documentation on Semantics of package Registry files](https://discourse.julialang.org/t/documentation-on-semantics-of-package-registry-files/31774)

<div class="topic-metadata">

**Author:** [@non-Jedi](https://discourse.julialang.org/u/non-Jedi)\
**Replies:** 0\
**Last updated:** [December 2, 2019, 8:44pm UTC](https://discourse.julialang.org/t/documentation-on-semantics-of-package-registry-files/31774 "2019-12-02T20:44:13Z")

</div>

Is there documentation somewhere on the semantics of the various toml files in Julia package registries? There was a release of a package as a patch version bump with a change in api that broke a downstream package, and …

---

## [Hover over Latex/ Unicode Character to see the Latex Sourcecode](https://discourse.julialang.org/t/hover-over-latex-unicode-character-to-see-the-latex-sourcecode/31749)

<div class="topic-metadata">

**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 5\
**Last updated:** [December 2, 2019, 7:47pm UTC](https://discourse.julialang.org/t/hover-over-latex-unicode-character-to-see-the-latex-sourcecode/31749 "2019-12-02T19:47:27Z")

</div>

Hey :slight\_smile: I really like the unicode support in Julia. But sometime it’s hard to differentiate different latex character. Wouldn’t it be nice if there were a way to look them up and maybe get the latex source co…

---

## [Help setting up convolution in NNLib.jl](https://discourse.julialang.org/t/help-setting-up-convolution-in-nnlib-jl/31769)

<div class="topic-metadata">

**Author:** [@stormyweathers](https://discourse.julialang.org/u/stormyweathers)\
**Replies:** 0\
**Last updated:** [December 2, 2019, 6:36pm UTC](https://discourse.julialang.org/t/help-setting-up-convolution-in-nnlib-jl/31769 "2019-12-02T18:36:23Z")

</div>

Hey there, new Julia user here trying to get acclimated. As a warm-up example, I want to build a GPU accelerated heat-equation explicit time-stepper. I am trying to implement the discrete laplacian using a convolution…

---

## [Is dijkstra\_shortest\_paths only supposed to handle integer weights?](https://discourse.julialang.org/t/is-dijkstra-shortest-paths-only-supposed-to-handle-integer-weights/31761)

<div class="topic-metadata">

**Author:** [@HBreddam](https://discourse.julialang.org/u/HBreddam)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 5:54pm UTC](https://discourse.julialang.org/t/is-dijkstra-shortest-paths-only-supposed-to-handle-integer-weights/31761 "2019-12-02T17:54:54Z")

</div>

Hi everyone, I need to have float weight on a graph as it is used as a pricing problem for column generation. As far as i can see the dijkstra\_shortest\_paths should be able use float weight, but when i try the followin…

---

## [Accessibility tools for visually impaired using Juno?](https://discourse.julialang.org/t/accessibility-tools-for-visually-impaired-using-juno/31730)

<div class="topic-metadata">

**Author:** [@klaff](https://discourse.julialang.org/u/klaff)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 5:34pm UTC](https://discourse.julialang.org/t/accessibility-tools-for-visually-impaired-using-juno/31730 "2019-12-02T17:34:55Z")

</div>

Does anyone have experience with using Juno and screen reader software? I have a coworker who needs such software and am wondering how they perform with Atom/Juno and with the LaTeX extension characters. How do they rea…

---

## [What could I use to visualise/graphically represent a model written in Julia?](https://discourse.julialang.org/t/what-could-i-use-to-visualise-graphically-represent-a-model-written-in-julia/31764)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 0\
**Last updated:** [December 2, 2019, 4:20pm UTC](https://discourse.julialang.org/t/what-could-i-use-to-visualise-graphically-represent-a-model-written-in-julia/31764 "2019-12-02T16:20:37Z")

</div>

Hello, I found the STELLA software (here a video of the representation of the climate change DICE model), and I has been impressed by the way I can represent graphically complicate models. Of course I would keep Julia t…

---

## [Keep a log of vehicle routes for animation purpose](https://discourse.julialang.org/t/keep-a-log-of-vehicle-routes-for-animation-purpose/31667)

<div class="topic-metadata">

**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 5\
**Last updated:** [December 2, 2019, 2:27pm UTC](https://discourse.julialang.org/t/keep-a-log-of-vehicle-routes-for-animation-purpose/31667 "2019-12-02T14:27:24Z")

</div>

Hi, I was doing a project to animate vehicle transportations on a road network. During the process, the vehicle will stay in a position for a certain time interval, travel to a certain location to pick up goods and then …

---

## [Is it possible to link julia to mkl without recompiling from source?](https://discourse.julialang.org/t/is-it-possible-to-link-julia-to-mkl-without-recompiling-from-source/31752)

<div class="topic-metadata">

**Author:** [@kirk](https://discourse.julialang.org/u/kirk)\
**Replies:** 0\
**Last updated:** [December 2, 2019, 1:42pm UTC](https://discourse.julialang.org/t/is-it-possible-to-link-julia-to-mkl-without-recompiling-from-source/31752 "2019-12-02T13:42:24Z")

</div>

Is it possible to use mkl instead of blas without having to recompile julia from source? For instance, through some configuration file where we can point where the mkl lib is on the system and then julia can recognise an…

---

## [\[ANN\] SequentialConvexRelaxation.jl: non-convex optimization on top of Convex.jl](https://discourse.julialang.org/t/ann-sequentialconvexrelaxation-jl-non-convex-optimization-on-top-of-convex-jl/31743)

<div class="topic-metadata">

**Author:** [@rdoelman](https://discourse.julialang.org/u/rdoelman)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 1:59pm UTC](https://discourse.julialang.org/t/ann-sequentialconvexrelaxation-jl-non-convex-optimization-on-top-of-convex-jl/31743 "2019-12-02T13:59:21Z")

</div>

Hi all, I’d like to introduce the package SequentialConvexRelaxation.jl. The package implements a heuristic method on top of Convex.jl to attempt to solve non-convex problems that can be expressed as a convex problem, …

---

## [Does SimJulia support parallel computation?](https://discourse.julialang.org/t/does-simjulia-support-parallel-computation/31698)

<div class="topic-metadata">

**Author:** [@zhangliye](https://discourse.julialang.org/u/zhangliye)\
**Replies:** 6\
**Last updated:** [December 2, 2019, 12:48pm UTC](https://discourse.julialang.org/t/does-simjulia-support-parallel-computation/31698 "2019-12-02T12:48:04Z")

</div>

I have developed a traffic simulation package using SimJulia. When the network is larger, the simulation is not quick enough. Does anyone know whether SimJulia supports the parallel calculation? This is not mentioned in…

---

## [Is there something better than \`reshape\` for flattening data batches?](https://discourse.julialang.org/t/is-there-something-better-than-reshape-for-flattening-data-batches/31744)

<div class="topic-metadata">

**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 3\
**Last updated:** [December 2, 2019, 12:16pm UTC](https://discourse.julialang.org/t/is-there-something-better-than-reshape-for-flattening-data-batches/31744 "2019-12-02T12:16:52Z")

</div>

In the MINST example of Flux Model Zoo, the layer that “flattens” tensor data before the Dense layer uses reshape: # Reshape 3d tensor into a 2d one, at this point it should be (3, 3, 32, N) # which is where we get the …

---

## [Dubious code: @spawn psort!(v, lo, mid)](https://discourse.julialang.org/t/dubious-code-spawn-psort-v-lo-mid/31742)

<div class="topic-metadata">

**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 12:03pm UTC](https://discourse.julialang.org/t/dubious-code-spawn-psort-v-lo-mid/31742 "2019-12-02T12:03:25Z")

</div>

Here is the code snippet taken from Announcing composable multi-threaded parallelism in Julia import Base.Threads.@spawn # sort the elements of \`v\` in place, from indices \`lo\` to \`hi\` inclusive function psort!(v, lo::…

---

## [MatrixEquations.jl: A package for solving Lyapunov, Sylvester and Riccati matrix equations with dense matrices](https://discourse.julialang.org/t/matrixequations-jl-a-package-for-solving-lyapunov-sylvester-and-riccati-matrix-equations-with-dense-matrices/31740)

<div class="topic-metadata">

**Author:** [@andreasvarga](https://discourse.julialang.org/u/andreasvarga)\
**Replies:** 0\
**Last updated:** [December 2, 2019, 11:24am UTC](https://discourse.julialang.org/t/matrixequations-jl-a-package-for-solving-lyapunov-sylvester-and-riccati-matrix-equations-with-dense-matrices/31740 "2019-12-02T11:24:33Z")

</div>

I would like to announce a new package MatrixEquations.jl for solving linear and quadratic matrix equations which frequently appear in control systems related computations. Solvers are provided for several classes of Lya…

---

## [Has GPU support changed since Flux 0.10?](https://discourse.julialang.org/t/has-gpu-support-changed-since-flux-0-10/31695)

<div class="topic-metadata">

**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 10:40am UTC](https://discourse.julialang.org/t/has-gpu-support-changed-since-flux-0-10/31695 "2019-12-02T10:40:21Z")

</div>

I get an error message related to CuArrays when I import Flux julia\> using Flux \[ Info: CuArrays.jl failed to initialize and will be unavailable (set JULIA\_CUDA\_SILENT or JULIA\_CUDA\_VERBOSE to silence or expand this mes…

---

## [Data Science for Managers: Programming Languages](https://discourse.julialang.org/t/data-science-for-managers-programming-languages/31699)

<div class="topic-metadata">

**Author:** [@Gunter\_Faes](https://discourse.julialang.org/u/Gunter_Faes)\
**Replies:** 11\
**Last updated:** [December 2, 2019, 10:32am UTC](https://discourse.julialang.org/t/data-science-for-managers-programming-languages/31699 "2019-12-02T10:32:33Z")

</div>

I found this interesting article about data analysis languages on KDnuggetes. Julia is described as follows by ActiveWizards: Julia is a high-level, high-performance dynamic programming language for numerical computin…

---

## [Juno.@run doesn't stop at breakpoints in package code](https://discourse.julialang.org/t/juno-run-doesnt-stop-at-breakpoints-in-package-code/31737)

<div class="topic-metadata">

**Author:** [@cserteGT3](https://discourse.julialang.org/u/cserteGT3)\
**Replies:** 2\
**Last updated:** [December 2, 2019, 9:23am UTC](https://discourse.julialang.org/t/juno-run-doesnt-stop-at-breakpoints-in-package-code/31737 "2019-12-02T09:23:39Z")

</div>

I’m trying to debug my package with Juno’s builtin debugger, but it ignores the breakpoints I put in the files. The package is \]dev-ed, and using Revise is called before using it. Debugging works, I can step through the …

---

## [Workers cannot access to RemoteChanel data during Parallel processing of dataframes](https://discourse.julialang.org/t/workers-cannot-access-to-remotechanel-data-during-parallel-processing-of-dataframes/31568)

<div class="topic-metadata">

**Author:** [@Fred](https://discourse.julialang.org/u/Fred)\
**Replies:** 1\
**Last updated:** [December 2, 2019, 9:05am UTC](https://discourse.julialang.org/t/workers-cannot-access-to-remotechanel-data-during-parallel-processing-of-dataframes/31568 "2019-12-02T09:05:13Z")

</div>

Hi, I have an error while processing dataframes in parallel. This is a toy program reproducing the problem with only one worker. Thank you for your help ! using Distributed using DataFrames df1 = DataFrame(A = \["R1", …

---

## [Converting symbols to types and splatting inside @eval](https://discourse.julialang.org/t/converting-symbols-to-types-and-splatting-inside-eval/31728)

<div class="topic-metadata">

**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 10\
**Last updated:** [December 2, 2019, 7:52am UTC](https://discourse.julialang.org/t/converting-symbols-to-types-and-splatting-inside-eval/31728 "2019-12-02T07:52:48Z")

</div>

I am trying to wrap my head around metaprogramming and macros and I struggle to figure this out and I think I am on the wrong path. I have the feeling that I need to build up an expression tree programmatically instead o…

---

## [Version of library in binary builds](https://discourse.julialang.org/t/version-of-library-in-binary-builds/31592)

<div class="topic-metadata">

**Author:** [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Replies:** 6\
**Last updated:** [December 2, 2019, 7:42am UTC](https://discourse.julialang.org/t/version-of-library-in-binary-builds/31592 "2019-12-02T07:42:23Z")

</div>

When I run the binary build of Julia-1.2.0 or Julia-1.3.0 under a clean install of Ubuntu-19.10 I encounter problems with the version of libstdc++ in the binary build. This comes about when using RCall and loading R pac…

[Previous page](https://discourse.julialang.org/latest.md?page=1869)

[Next page](https://discourse.julialang.org/latest.md?page=1871)