# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1014

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

**Page:** 1015

---

## [GLM.jl LogisticRegression errors: matrix is not positive definite; Cholesky factorization failed](https://discourse.julialang.org/t/glm-jl-logisticregression-errors-matrix-is-not-positive-definite-cholesky-factorization-failed/28981)

<div class="topic-metadata">

**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 14\
**Last updated:** [June 9, 2022, 10:04pm UTC](https://discourse.julialang.org/t/glm-jl-logisticregression-errors-matrix-is-not-positive-definite-cholesky-factorization-failed/28981 "2022-06-09T22:04:16Z")

</div>

The following errors: using DataFrames, GLM df = DataFrame(x1=\[1,2,3,4\], x2=\[1,2,3,4\], y=\[1,1,0,0\]) mdl = glm(@formula(y~x1+x2), df, Binomial(), LogitLink()) predict(mdl, df\[:, \[:x1, :x2\]\]) ERROR: LoadError: PosDef…

---

## [Why does Tuple not have AbstractVector semantics?](https://discourse.julialang.org/t/why-does-tuple-not-have-abstractvector-semantics/82237)

<div class="topic-metadata">

**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 20\
**Last updated:** [June 9, 2022, 9:37pm UTC](https://discourse.julialang.org/t/why-does-tuple-not-have-abstractvector-semantics/82237 "2022-06-09T21:37:30Z")

</div>

This came up along time ago, and I’m puzzling through it today: https://github.com/SciML/DifferentialEquations.jl/issues/566 We cannot use Tuples for DifferentialEquations.jl initial conditions, but everyone keeps aski…

---

## [Differences of Core.eval vs. running the code directly in other modules then Main](https://discourse.julialang.org/t/differences-of-core-eval-vs-running-the-code-directly-in-other-modules-then-main/82489)

<div class="topic-metadata">

**Author:** [@sfuerst](https://discourse.julialang.org/u/sfuerst)\
**Replies:** 4\
**Last updated:** [June 9, 2022, 9:27pm UTC](https://discourse.julialang.org/t/differences-of-core-eval-vs-running-the-code-directly-in-other-modules-then-main/82489 "2022-06-09T21:27:47Z")

</div>

While writing the documentation of a package I’m currently developing, I did ran into a problem with Documenter.jl which I could track down to the sandboxing mechanism of Documenter in combination with Core.eval. Withou…

---

## [How to plot matrix as gradient grid?](https://discourse.julialang.org/t/how-to-plot-matrix-as-gradient-grid/82187)

<div class="topic-metadata">

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 12\
**Last updated:** [June 9, 2022, 9:00pm UTC](https://discourse.julialang.org/t/how-to-plot-matrix-as-gradient-grid/82187 "2022-06-09T21:00:47Z")

</div>

Hello, I have a matrix of floating numbers that I would like to plot as a grid whose cells are shaded according to these numbers. Thus, having julia\> grid = rand(Float32, 5, 5) 5×5 Matrix{Float32}: 0.157996 0.965474 …

---

## [\[ANN\] Sparspak: suite of solvers for linear algebraic equations in Julia](https://discourse.julialang.org/t/ann-sparspak-suite-of-solvers-for-linear-algebraic-equations-in-julia/82461)

<div class="topic-metadata">

**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 8\
**Last updated:** [June 9, 2022, 8:45pm UTC](https://discourse.julialang.org/t/ann-sparspak-suite-of-solvers-for-linear-algebraic-equations-in-julia/82461 "2022-06-09T20:45:36Z")

</div>

\# Sparspak.jl Translation into Julia of the well-known sparse matrix software Sparspak (Waterloo Sparse Matrix Package) for solving large sparse systems of linear algebraic equations. Sparspak was composed originally o…

---

## [Interpolation using $ with @cfunction in a macro reported as a closure, thus won't work on Apple Silicon](https://discourse.julialang.org/t/interpolation-using-with-cfunction-in-a-macro-reported-as-a-closure-thus-wont-work-on-apple-silicon/75984)

<div class="topic-metadata">

**Author:** [@jackbeagley](https://discourse.julialang.org/u/jackbeagley)\
**Replies:** 8\
**Last updated:** [June 9, 2022, 8:44pm UTC](https://discourse.julialang.org/t/interpolation-using-with-cfunction-in-a-macro-reported-as-a-closure-thus-wont-work-on-apple-silicon/75984 "2022-06-09T20:44:08Z")

</div>

I’m still learning about macros and only recently learnt about closures. I am trying to use the ArchGDAL package on my Apple Silicon Macbook, but it reported an error during precompilation: ERROR: LoadError: cfunction: c…

---

## [Solving symbolic system of equations using Ax = b](https://discourse.julialang.org/t/solving-symbolic-system-of-equations-using-ax-b/82454)

<div class="topic-metadata">

**Author:** [@jpro](https://discourse.julialang.org/u/jpro)\
**Replies:** 9\
**Last updated:** [June 9, 2022, 8:29pm UTC](https://discourse.julialang.org/t/solving-symbolic-system-of-equations-using-ax-b/82454 "2022-06-09T20:29:55Z")

</div>

I’m attempting to solve a system of 8 vector equations with 8 unknown vectors symbolically in Julia using Ax = b. The matrix is 24\*24 (due to 3-dimensional vectors) of variables I’ve defined using @ vars After defining …

---

## [Add Dollar Signs to Axis](https://discourse.julialang.org/t/add-dollar-signs-to-axis/82524)

<div class="topic-metadata">

**Author:** [@gjh](https://discourse.julialang.org/u/gjh)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 8:14pm UTC](https://discourse.julialang.org/t/add-dollar-signs-to-axis/82524 "2022-06-09T20:14:59Z")

</div>

I want to add dollar signs to the x and y-axis (e.g., $10K). I’m sure I am missing something simple. Thank you for any help!!! using Gadfly, Printf plot(x=rand(10)\*10\_000, y=rand(10)\*10\_000, Scale.x\_continuous(labels…

---

## [How to put a single marker on a heatmap](https://discourse.julialang.org/t/how-to-put-a-single-marker-on-a-heatmap/82447)

<div class="topic-metadata">

**Author:** [@Xavier\_Gonzalez](https://discourse.julialang.org/u/Xavier_Gonzalez)\
**Replies:** 12\
**Last updated:** [June 9, 2022, 8:05pm UTC](https://discourse.julialang.org/t/how-to-put-a-single-marker-on-a-heatmap/82447 "2022-06-09T20:05:03Z")

</div>

I’m using CairoMakie to make a heatmap in Julia 1.7.3 I’d like to add a single smiley face (or really any marker) in the very center of the heatmap, at say 50 x 50. This seems like a super simple task, but I’ve been lo…

---

## [Can somebody explain this syntax?](https://discourse.julialang.org/t/can-somebody-explain-this-syntax/82519)

<div class="topic-metadata">

**Author:** [@Sharath\_Gururaj](https://discourse.julialang.org/u/Sharath_Gururaj)\
**Replies:** 3\
**Last updated:** [June 9, 2022, 7:52pm UTC](https://discourse.julialang.org/t/can-somebody-explain-this-syntax/82519 "2022-06-09T19:52:27Z")

</div>

We know that Typenames can be used as constructors for example Float64(1.0) I wanted to check how this is possible, so I ran @which Float64(1.0) It printed the following (::Type{T})(x::T) where {T\<:Number} = x Wha…

---

## [Speed up Gaussian Process model](https://discourse.julialang.org/t/speed-up-gaussian-process-model/82315)

<div class="topic-metadata">

**Author:** [@EvoArt](https://discourse.julialang.org/u/EvoArt)\
**Replies:** 16\
**Last updated:** [June 9, 2022, 7:43pm UTC](https://discourse.julialang.org/t/speed-up-gaussian-process-model/82315 "2022-06-09T19:43:42Z")

</div>

Hi all I am interested in implementing a latent variable Gaussian process regression model with a pre-calculated (phylogenetic) distance matrix. The below model (mostly copied from here and based on this runs, and get’s…

---

## [Juliaup breaks after failed auto upgrade](https://discourse.julialang.org/t/juliaup-breaks-after-failed-auto-upgrade/82521)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 6:54pm UTC](https://discourse.julialang.org/t/juliaup-breaks-after-failed-auto-upgrade/82521 "2022-06-09T18:54:35Z")

</div>

I’m getting this error when trying to start Julia from juliaup. A few days ago it worked. Note that I get back to the shell, then julia starts, but soon later I get those “IOError” stream errors. Any idea? ~% julia The…

---

## [How to make Julia code faster than python code?](https://discourse.julialang.org/t/how-to-make-julia-code-faster-than-python-code/82381)

<div class="topic-metadata">

**Author:** [@YitaoCai](https://discourse.julialang.org/u/YitaoCai)\
**Replies:** 10\
**Last updated:** [June 9, 2022, 6:02pm UTC](https://discourse.julialang.org/t/how-to-make-julia-code-faster-than-python-code/82381 "2022-06-09T18:02:36Z")

</div>

I found my Juila code is way slower than python code, it keeps running for more than 2 hours and no results, so I terminated it. Python code gave results in 1 hour. Here is the original python code: def ImageTiler(file…

---

## ["Why I no longer recommend Julia" at JuliaCon 2022?](https://discourse.julialang.org/t/why-i-no-longer-recommend-julia-at-juliacon-2022/82070)

<div class="topic-metadata">

**Author:** [@matthias314](https://discourse.julialang.org/u/matthias314)\
**Replies:** 19\
**Last updated:** [June 9, 2022, 5:39pm UTC](https://discourse.julialang.org/t/why-i-no-longer-recommend-julia-at-juliacon-2022/82070 "2022-06-09T17:39:10Z")

</div>

The thread Discussion on “Why I no longer recommend Julia” by Yuri Vishnevsky seems to generate a huge amount of interest. What about having a panel discussion along these lines at the upcoming JuliaCon 2022? Moreover, i…

---

## [Application compilation does not account for required code](https://discourse.julialang.org/t/application-compilation-does-not-account-for-required-code/82515)

<div class="topic-metadata">

**Author:** [@BambOoxX](https://discourse.julialang.org/u/BambOoxX)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 4:59pm UTC](https://discourse.julialang.org/t/application-compilation-does-not-account-for-required-code/82515 "2022-06-09T16:59:39Z")

</div>

I’m currently trying to compile an app using PackageCompiler. The associated project App depends on two packages Foo and Bar. Foo contains a bit of glue code to link with Bar-provided functionnalities. These portion of…

---

## [Understanding NLSolvers Package through the Given Documentation](https://discourse.julialang.org/t/understanding-nlsolvers-package-through-the-given-documentation/82512)

<div class="topic-metadata">

**Author:** [@MJF](https://discourse.julialang.org/u/MJF)\
**Replies:** 0\
**Last updated:** [June 9, 2022, 4:22pm UTC](https://discourse.julialang.org/t/understanding-nlsolvers-package-through-the-given-documentation/82512 "2022-06-09T16:22:07Z")

</div>

I am quite new to Julia and trying to figure out how to use the NLSolvers package as given in the following link: NLSolvers In the README file, they provide an example for a nonlinear system of equations for the Rosenbr…

---

## [A minimal CUDA-compatible and differentiable GP implementation](https://discourse.julialang.org/t/a-minimal-cuda-compatible-and-differentiable-gp-implementation/80099)

<div class="topic-metadata">

**Author:** [@Red-Portal](https://discourse.julialang.org/u/Red-Portal)\
**Replies:** 11\
**Last updated:** [June 9, 2022, 3:22pm UTC](https://discourse.julialang.org/t/a-minimal-cuda-compatible-and-differentiable-gp-implementation/80099 "2022-06-09T15:22:07Z")

</div>

Hi folks, I was really frustrated last week because it seems there isn’t a way to implement Gaussian processes with both CUDA acceleration and differentiation. Because of this, I had to roll my own CUDA kernels that did…

---

## [How to print a graph with LightGraphs](https://discourse.julialang.org/t/how-to-print-a-graph-with-lightgraphs/82506)

<div class="topic-metadata">

**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 3:09pm UTC](https://discourse.julialang.org/t/how-to-print-a-graph-with-lightgraphs/82506 "2022-06-09T15:09:35Z")

</div>

I have a graph which is of type Dict{Int64, Vector{Tuple{Int64, Float64}}}. The first three lines of graph are: 5 =\> \[(11, 34.54), (7, 3.33), (45, 1382.97)\] 56 =\> \[(61, 11.06), (57, 0.02), (76, 197.03)\] 35 =\> \[(50, 78.…

---

## [Using eval within a function](https://discourse.julialang.org/t/using-eval-within-a-function/82487)

<div class="topic-metadata">

**Author:** [@flobe](https://discourse.julialang.org/u/flobe)\
**Replies:** 7\
**Last updated:** [June 9, 2022, 2:31pm UTC](https://discourse.julialang.org/t/using-eval-within-a-function/82487 "2022-06-09T14:31:52Z")

</div>

I’m trying to build a statement for an if case within a function. Something like: function build\_string(test\_value, comparator, value) if eval(Meta.parse("test\_value" \* "comparator" \* "value")) \[...\] end … I ge…

---

## [Looking for panelists to join JuliaCon discussion on Enterprise Adoption of Julia](https://discourse.julialang.org/t/looking-for-panelists-to-join-juliacon-discussion-on-enterprise-adoption-of-julia/82469)

<div class="topic-metadata">

**Author:** [@James\_Lee](https://discourse.julialang.org/u/James_Lee)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 2:52pm UTC](https://discourse.julialang.org/t/looking-for-panelists-to-join-juliacon-discussion-on-enterprise-adoption-of-julia/82469 "2022-06-09T14:52:55Z")

</div>

Julius Tech is planning on hosting a BoF event at JuliaCon focusing on enterprise adoption of Julia and related tools. We’re looking for panelists who have some experience bringing Julia into their company and to share t…

---

## [Solving an analytical ODE \*slower\* than numerical?](https://discourse.julialang.org/t/solving-an-analytical-ode-slower-than-numerical/82499)

<div class="topic-metadata">

**Author:** [@dodoplus](https://discourse.julialang.org/u/dodoplus)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 2:51pm UTC](https://discourse.julialang.org/t/solving-an-analytical-ode-slower-than-numerical/82499 "2022-06-09T14:51:17Z")

</div>

The documentation (Composing Ordinary Differential Equations · ModelingToolkit.jl) gives the following example to show symbolic derivatives result in higher performance vs. numerical approximation: using BenchmarkTools …

---

## [Run two repls on the same project](https://discourse.julialang.org/t/run-two-repls-on-the-same-project/81620)

<div class="topic-metadata">

**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 2\
**Last updated:** [June 9, 2022, 2:25pm UTC](https://discourse.julialang.org/t/run-two-repls-on-the-same-project/81620 "2022-06-09T14:25:14Z")

</div>

I have a project with lots of modules I’m actively developing. But I also want to run some long running tasks based on it and occasionally update that, so I’ve been running a repl in vscode to develop, and a second one i…

---

## [Dispatch on the last layer type in Flux](https://discourse.julialang.org/t/dispatch-on-the-last-layer-type-in-flux/82481)

<div class="topic-metadata">

**Author:** [@DoktorMike](https://discourse.julialang.org/u/DoktorMike)\
**Replies:** 3\
**Last updated:** [June 9, 2022, 11:07am UTC](https://discourse.julialang.org/t/dispatch-on-the-last-layer-type-in-flux/82481 "2022-06-09T11:07:01Z")

</div>

I’m making an implementation of a Evidential Deep Learning model in Flux and I would like to have a function predict(model, x) where x is input data. The model is a Chain which consists possibly of many layers. I want th…

---

## [Why Pluto is much slower than Jupyter](https://discourse.julialang.org/t/why-pluto-is-much-slower-than-jupyter/82445)

<div class="topic-metadata">

**Author:** [@GoYetChallenged](https://discourse.julialang.org/u/GoYetChallenged)\
**Replies:** 10\
**Last updated:** [June 9, 2022, 10:04am UTC](https://discourse.julialang.org/t/why-pluto-is-much-slower-than-jupyter/82445 "2022-06-09T10:04:55Z")

</div>

I am trying migrating to Pluto from Jupyter notebook. I test a function written in Jupyter. however, for same codes, it becomes about 30 times slower than running in Jupyter. In Jupyter: BenchmarkTools.Trial: 2 sample…

---

## [Compilation time not vanishing on subsequent runs](https://discourse.julialang.org/t/compilation-time-not-vanishing-on-subsequent-runs/82431)

<div class="topic-metadata">

**Author:** [@mitchemi](https://discourse.julialang.org/u/mitchemi)\
**Replies:** 4\
**Last updated:** [June 9, 2022, 9:39am UTC](https://discourse.julialang.org/t/compilation-time-not-vanishing-on-subsequent-runs/82431 "2022-06-09T09:39:30Z")

</div>

Hi! I’ve got a relatively simple piece of code that takes an 2D array (“correlation”), and gives you a radial average working outwards from the centre. xs = range(1, 100, 100) ys = range(1, 100, 100) R(x, y) = (sqrt((x…

---

## [TOML Parser error](https://discourse.julialang.org/t/toml-parser-error/82474)

<div class="topic-metadata">

**Author:** [@ga72kud](https://discourse.julialang.org/u/ga72kud)\
**Replies:** 1\
**Last updated:** [June 9, 2022, 9:34am UTC](https://discourse.julialang.org/t/toml-parser-error/82474 "2022-06-09T09:34:41Z")

</div>

Hi I have a weird error. I don’t know how to handle it. TOML Parser error: none:3373:1 error: invalid bare key character: ‘\\0’ \[\[“/home/michael/.julia/environments/v1.6/Manifest.toml”\]\] ^ parse at toml\_parser.jl:441 …

---

## [Flux.jl confusion matrix](https://discourse.julialang.org/t/flux-jl-confusion-matrix/19740)

<div class="topic-metadata">

**Author:** [@essenciary](https://discourse.julialang.org/u/essenciary)\
**Replies:** 13\
**Last updated:** [June 9, 2022, 9:19am UTC](https://discourse.julialang.org/t/flux-jl-confusion-matrix/19740 "2022-06-09T09:19:10Z")

</div>

I’m using Flux to implement a handwritten digit classifier based on the MNIST dataset (ex https://github.com/FluxML/model-zoo/blob/master/vision/mnist/mlp.jl). Is there any way to compute the confusion matrix in order t…

---

## [Julia for Quantum Cryptography by edX](https://discourse.julialang.org/t/julia-for-quantum-cryptography-by-edx/82418)

<div class="topic-metadata">

**Author:** [@josh\_pat](https://discourse.julialang.org/u/josh_pat)\
**Replies:** 3\
**Last updated:** [June 9, 2022, 8:38am UTC](https://discourse.julialang.org/t/julia-for-quantum-cryptography-by-edx/82418 "2022-06-09T08:38:14Z")

</div>

I am taking an online course from edX on Quantum Cryptography. The course uses Julia for programming, and it is an important part of the learning experience. The Julia notebooks for this course are written for version 0…

---

## [Non-Diagonal SDE with matrix variables](https://discourse.julialang.org/t/non-diagonal-sde-with-matrix-variables/82351)

<div class="topic-metadata">

**Author:** [@thobili](https://discourse.julialang.org/u/thobili)\
**Replies:** 1\
**Last updated:** [June 7, 2022, 11:07am UTC](https://discourse.julialang.org/t/non-diagonal-sde-with-matrix-variables/82351 "2022-06-07T11:07:57Z")

</div>

I was trying to apply the method described at https://diffeq.sciml.ai/stable/tutorials/sde\_example/#Example-4:-Systems-of-SDEs-with-Non-Diagonal-Noise for a matrix valued variable, e.g. f(du,u,p,t) = du .= 1.01u funct…

---

## [PSA: Atom will be archived Dez. 15th](https://discourse.julialang.org/t/psa-atom-will-be-archived-dez-15th/82463)

<div class="topic-metadata">

**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 3\
**Last updated:** [June 9, 2022, 8:25am UTC](https://discourse.julialang.org/t/psa-atom-will-be-archived-dez-15th/82463 "2022-06-09T08:25:32Z")

</div>

GitHub announced the sunset of Atom Time to move to EMacs :wink:

[Previous page](https://discourse.julialang.org/latest.md?page=1013)

[Next page](https://discourse.julialang.org/latest.md?page=1015)