# Latest

**URL:** https://discourse.julialang.org/latest.md?page=816

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

**Page:** 817

---

## [Why \`inv(Complex(0.0, 0.0))\` returns \`Complex(NaN, NaN)\`?](https://discourse.julialang.org/t/why-inv-complex-0-0-0-0-returns-complex-nan-nan/92694)

<div class="topic-metadata">

**Author:** [@hyrodium](https://discourse.julialang.org/u/hyrodium)\
**Replies:** 12\
**Last updated:** [January 10, 2023, 4:15pm UTC](https://discourse.julialang.org/t/why-inv-complex-0-0-0-0-returns-complex-nan-nan/92694 "2023-01-10T16:15:39Z")

</div>

In Julia, inv(Complex(0.0, 0.0)) is evaluated as julia\> c = inv(Complex(0.0, 0.0)) NaN + NaN\*im julia\> isnan(c) true julia\> isinf(c) false julia\> versioninfo() Julia Version 1.8.4 Commit 00177ebc4fc (2022-12-23 21:32…

---

## [Should a macro throw an error, or return expression that throws an error?](https://discourse.julialang.org/t/should-a-macro-throw-an-error-or-return-expression-that-throws-an-error/92720)

<div class="topic-metadata">

**Author:** [@bbejanov](https://discourse.julialang.org/u/bbejanov)\
**Replies:** 6\
**Last updated:** [January 10, 2023, 3:55pm UTC](https://discourse.julialang.org/t/should-a-macro-throw-an-error-or-return-expression-that-throws-an-error/92720 "2023-01-10T15:55:03Z")

</div>

I have a macro that in some circumstances must throw an error. Is there a recommended way of doing that? For example, I can throw the error directly from the macro, or return code that throws the error. macro A() i…

---

## [Is it possible to plot gain margin and phase margin on the bode diagram?](https://discourse.julialang.org/t/is-it-possible-to-plot-gain-margin-and-phase-margin-on-the-bode-diagram/89876)

<div class="topic-metadata">

**Author:** [@lucasmsoares96](https://discourse.julialang.org/u/lucasmsoares96)\
**Replies:** 5\
**Last updated:** [January 10, 2023, 3:12pm UTC](https://discourse.julialang.org/t/is-it-possible-to-plot-gain-margin-and-phase-margin-on-the-bode-diagram/89876 "2023-01-10T15:12:39Z")

</div>

I didn’t find anything about this in the documentation.

---

## [Getting the original name of structs](https://discourse.julialang.org/t/getting-the-original-name-of-structs/92757)

<div class="topic-metadata">

**Author:** [@lklein](https://discourse.julialang.org/u/lklein)\
**Replies:** 2\
**Last updated:** [January 10, 2023, 3:01pm UTC](https://discourse.julialang.org/t/getting-the-original-name-of-structs/92757 "2023-01-10T15:01:17Z")

</div>

I want to write a function get\_original\_name(::DataType) that returns the original name used when declaring a struct. Is there any way to do this? Is the original name even distinguishable from names that were added late…

---

## [MethodOfLines.jl: Obtain Jacobian of MOL semi-discretization](https://discourse.julialang.org/t/methodoflines-jl-obtain-jacobian-of-mol-semi-discretization/92681)

<div class="topic-metadata">

**Author:** [@DanDoe](https://discourse.julialang.org/u/DanDoe)\
**Replies:** 5\
**Last updated:** [January 10, 2023, 1:41pm UTC](https://discourse.julialang.org/t/methodoflines-jl-obtain-jacobian-of-mol-semi-discretization/92681 "2023-01-10T13:41:40Z")

</div>

Consider an exemplary PDE with temporal & spatial derivatives \\partial\_t u(t, x) + D\_x f\\big(u(t, x)\\big) = 0 Where D\_x is a general differential operator, like the Laplacian and f is some function. I can use MethodO…

---

## [An idea for using ccall less in BigFloat operations](https://discourse.julialang.org/t/an-idea-for-using-ccall-less-in-bigfloat-operations/92755)

<div class="topic-metadata">

**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 0\
**Last updated:** [January 10, 2023, 1:15pm UTC](https://discourse.julialang.org/t/an-idea-for-using-ccall-less-in-bigfloat-operations/92755 "2023-01-10T13:15:05Z")

</div>

I got an idea for a way to slightly decrease the ccall-ing of libmpfr within the Base.MPFR module, which implements BigFloat. Julia defines the BigFloat type as a mutable struct with a number of fields, and it seems lik…

---

## [GraphRecipes: Setting nodesize independently of node names?](https://discourse.julialang.org/t/graphrecipes-setting-nodesize-independently-of-node-names/80543)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 1\
**Last updated:** [January 10, 2023, 12:41pm UTC](https://discourse.julialang.org/t/graphrecipes-setting-nodesize-independently-of-node-names/80543 "2023-01-10T12:41:32Z")

</div>

At the following link to GraphReceipes, the following description can be found for the attribute “nodesize” “The size of nodes in the plot coordinates. Note that if names is not empty, then nodes will be scaled to fit t…

---

## [Initializing a matrix of matrices](https://discourse.julialang.org/t/initializing-a-matrix-of-matrices/92743)

<div class="topic-metadata">

**Author:** [@dfb1002](https://discourse.julialang.org/u/dfb1002)\
**Replies:** 17\
**Last updated:** [January 10, 2023, 12:10pm UTC](https://discourse.julialang.org/t/initializing-a-matrix-of-matrices/92743 "2023-01-10T12:10:26Z")

</div>

Hi everyone, I have found these posts: Neither seems to do exactly what I want. I am trying to create a matrix of matrices. I need the structure to be in this way for what I am working on. I will provide an example. …

---

## [When to update agent property that depends on moves of all other agents](https://discourse.julialang.org/t/when-to-update-agent-property-that-depends-on-moves-of-all-other-agents/92695)

<div class="topic-metadata">

**Author:** [@SDA](https://discourse.julialang.org/u/SDA)\
**Replies:** 5\
**Last updated:** [January 10, 2023, 11:53am UTC](https://discourse.julialang.org/t/when-to-update-agent-property-that-depends-on-moves-of-all-other-agents/92695 "2023-01-10T11:53:30Z")

</div>

Hi everyone, I’m confused about how an agent property should be best updated within the Agents.jl package. At each time step, each agent does some computation and then moves to a new location. The agent property should…

---

## [Processing RTK GPS data in Julia?](https://discourse.julialang.org/t/processing-rtk-gps-data-in-julia/92753)

<div class="topic-metadata">

**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 0\
**Last updated:** [January 10, 2023, 11:10am UTC](https://discourse.julialang.org/t/processing-rtk-gps-data-in-julia/92753 "2023-01-10T11:10:52Z")

</div>

Hi everyone, At work we installed two gps, one fixed and a rover, in order to geo-located the optical fibre. I would like to just correct the rover position according to the fixed antenna. Is there a package for this …

---

## [|n\> as notation for function piping n times?](https://discourse.julialang.org/t/n-as-notation-for-function-piping-n-times/92712)

<div class="topic-metadata">

**Author:** [@jd-foster](https://discourse.julialang.org/u/jd-foster)\
**Replies:** 5\
**Last updated:** [January 10, 2023, 11:02am UTC](https://discourse.julialang.org/t/n-as-notation-for-function-piping-n-times/92712 "2023-01-10T11:02:43Z")

</div>

Suppose you wanted to repeatedly compose a certain function via piping. For sake of argument, say we want to do 3 |\> sqrt |\> sqrt |\> sqrt |\> sqrt One can do this for an arbitrary number of times n (where n = 4 above) u…

---

## [Incremental compilation broken](https://discourse.julialang.org/t/incremental-compilation-broken/71944)

<div class="topic-metadata">

**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 7\
**Last updated:** [January 10, 2023, 2:17am UTC](https://discourse.julialang.org/t/incremental-compilation-broken/71944 "2023-01-10T02:17:39Z")

</div>

I get this: WARNING: Method definition (::Type{Float32})(Base.Irrational{:loghalf}) in module IrrationalConstants at irrationals.jl:190 overwritten in module StatsFuns on the same line (check for duplicate calls to \`inc…

---

## [GLMakie and Plots fail to precompile under Julia 1.8.4](https://discourse.julialang.org/t/glmakie-and-plots-fail-to-precompile-under-julia-1-8-4/92087)

<div class="topic-metadata">

**Author:** [@tt1234567](https://discourse.julialang.org/u/tt1234567)\
**Replies:** 56\
**Last updated:** [January 10, 2023, 10:34am UTC](https://discourse.julialang.org/t/glmakie-and-plots-fail-to-precompile-under-julia-1-8-4/92087 "2023-01-10T10:34:34Z")

</div>

Today I updated to Julia 1.8.4 but GLMakie and Plots bothe fail to precompile. The first error that occurs is similar in both cases and refers to \\libcairo-2.dll, eg: using GLMakie \[ Info: Precompiling GLMakie \[e9467ef8…

---

## [Pgfplotsx with \\mathbb](https://discourse.julialang.org/t/pgfplotsx-with-mathbb/92747)

<div class="topic-metadata">

**Author:** [@Elyco](https://discourse.julialang.org/u/Elyco)\
**Replies:** 2\
**Last updated:** [January 10, 2023, 10:21am UTC](https://discourse.julialang.org/t/pgfplotsx-with-mathbb/92747 "2023-01-10T10:21:10Z")

</div>

Hi, I’m trying to put a latex label \\mathbb{R} with pgfplotsx() backend. But I get an error: using Plots using LaTeXStrings pgfplotsx() plot(rand(10), label=L"\\mathcal{R}^{2N}") |\> display # works! plot(rand(10), labe…

---

## [Why does each BigFloat allocate a big String in addition to the MPFR big float object?](https://discourse.julialang.org/t/why-does-each-bigfloat-allocate-a-big-string-in-addition-to-the-mpfr-big-float-object/92745)

<div class="topic-metadata">

**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 7\
**Last updated:** [January 10, 2023, 9:57am UTC](https://discourse.julialang.org/t/why-does-each-bigfloat-allocate-a-big-string-in-addition-to-the-mpfr-big-float-object/92745 "2023-01-10T09:57:25Z")

</div>

I’m doing allocation profiling on some code that uses BigFloats at precision 2048, and I noticed that each time a BigFloat is allocated, half of the allocation seems to go to the MPFR object, and the other half to a Stri…

---

## [How to add Visitor Counter in a website made by Franklin.jl package?](https://discourse.julialang.org/t/how-to-add-visitor-counter-in-a-website-made-by-franklin-jl-package/92746)

<div class="topic-metadata">

**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 1\
**Last updated:** [January 10, 2023, 8:05am UTC](https://discourse.julialang.org/t/how-to-add-visitor-counter-in-a-website-made-by-franklin-jl-package/92746 "2023-01-10T08:05:56Z")

</div>

How to add Visitor Counter in Franklin.jl Website in footer ? What codes should be added ?

---

## [How to Convert Computation Result in Julia in pi terms?](https://discourse.julialang.org/t/how-to-convert-computation-result-in-julia-in-pi-terms/92700)

<div class="topic-metadata">

**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 4\
**Last updated:** [January 10, 2023, 7:22am UTC](https://discourse.julialang.org/t/how-to-convert-computation-result-in-julia-in-pi-terms/92700 "2023-01-10T07:22:35Z")

</div>

Hi all, I want to show the result of my computation in pi terms, instead of float with lots of decimal numbers. Is it possible? Here is my code: using Plots, LaTeXStrings; gr() #= # To plot a curve starting at (0, 0) …

---

## [\[CONTROL SYSTEMS\] - MIMO system through array of SISO](https://discourse.julialang.org/t/control-systems-mimo-system-through-array-of-siso/92718)

<div class="topic-metadata">

**Author:** [@pyKuga](https://discourse.julialang.org/u/pyKuga)\
**Replies:** 5\
**Last updated:** [January 10, 2023, 6:06am UTC](https://discourse.julialang.org/t/control-systems-mimo-system-through-array-of-siso/92718 "2023-01-10T06:06:39Z")

</div>

Greetings. I would like to know if it’s possible, in ControlSystems.jl, to reach an MIMO system through an array of TransferFunctions. Let’s suppose that we have a matrix H, which is related to a Y = H\*U, where Y is a …

---

## [NeuralPDE passing current grid point the the loss and activation funciton](https://discourse.julialang.org/t/neuralpde-passing-current-grid-point-the-the-loss-and-activation-funciton/92729)

<div class="topic-metadata">

**Author:** [@c\_sell](https://discourse.julialang.org/u/c_sell)\
**Replies:** 1\
**Last updated:** [January 10, 2023, 2:41am UTC](https://discourse.julialang.org/t/neuralpde-passing-current-grid-point-the-the-loss-and-activation-funciton/92729 "2023-01-10T02:41:34Z")

</div>

Hello everyone, i have three questions regarding the NeuralPDE package: is it possible to pass the current grid point to the additional cost function? I would like to take the derivative at the boundary of the domain …

---

## [MATLAB outperforms Julia (20 times faster) running this nested loop](https://discourse.julialang.org/t/matlab-outperforms-julia-20-times-faster-running-this-nested-loop/92691)

<div class="topic-metadata">

**Author:** [@SantiagoOrtiz](https://discourse.julialang.org/u/SantiagoOrtiz)\
**Replies:** 20\
**Last updated:** [January 10, 2023, 2:03am UTC](https://discourse.julialang.org/t/matlab-outperforms-julia-20-times-faster-running-this-nested-loop/92691 "2023-01-10T02:03:30Z")

</div>

Hello Fellas, I am relatively new to Julia Programming. So far, Julia’s high performance has caught my attention. However, it was disappointing to see that MATLAB performs 20 times faster in executing the following prog…

---

## [Using MATLAB Package with R2022b and R2021b downloaded](https://discourse.julialang.org/t/using-matlab-package-with-r2022b-and-r2021b-downloaded/90785)

<div class="topic-metadata">

**Author:** [@dfb1002](https://discourse.julialang.org/u/dfb1002)\
**Replies:** 27\
**Last updated:** [January 10, 2023, 2:01am UTC](https://discourse.julialang.org/t/using-matlab-package-with-r2022b-and-r2021b-downloaded/90785 "2023-01-10T02:01:53Z")

</div>

Hello, I am trying to use the MATLAB package, which I have read has a bug with both the R2022a and R2022b Matlab versions. I have R2021b installed, but when I attempt to build the package, it returns an error because it…

---

## [Hyperopt.jl Hyperband states existing variables are undefined](https://discourse.julialang.org/t/hyperopt-jl-hyperband-states-existing-variables-are-undefined/92740)

<div class="topic-metadata">

**Author:** [@RLB](https://discourse.julialang.org/u/RLB)\
**Replies:** 0\
**Last updated:** [January 10, 2023, 1:30am UTC](https://discourse.julialang.org/t/hyperopt-jl-hyperband-states-existing-variables-are-undefined/92740 "2023-01-10T01:30:37Z")

</div>

Package Versions: Julia - v1.8.3 Flux - v0.13.9 Hyperopt - v0.5.6 I’m attempting to use the Hyperopt.jl package to help tune the layers and number of nodes in a neural network. I would like to be able to use their im…

---

## [Julia v1.8.5 has been released](https://discourse.julialang.org/t/julia-v1-8-5-has-been-released/92738)

<div class="topic-metadata">

**Author:** [@ararslan](https://discourse.julialang.org/u/ararslan)\
**Replies:** 0\
**Last updated:** [January 10, 2023, 1:23am UTC](https://discourse.julialang.org/t/julia-v1-8-5-has-been-released/92738 "2023-01-10T01:23:20Z")

</div>

The Julia developers are pleased to announce the release of v1.8.5, the fifth patch release in the 1.8 stable series. You can download binaries at https://julialang.org/downloads in the “current stable release” section. …

---

## [Color-blind-friendly color sequence (palette) for line graphs](https://discourse.julialang.org/t/color-blind-friendly-color-sequence-palette-for-line-graphs/92551)

<div class="topic-metadata">

**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 24\
**Last updated:** [January 10, 2023, 12:34am UTC](https://discourse.julialang.org/t/color-blind-friendly-color-sequence-palette-for-line-graphs/92551 "2023-01-10T00:34:01Z")

</div>

I’d like to know “what” the default color sequence is for line graphs, such as the sample code below generates. In particular I’d like to know whether consideration has gone into the color palette about color blindness.…

---

## [Find DataFrame row with missing values present](https://discourse.julialang.org/t/find-dataframe-row-with-missing-values-present/92728)

<div class="topic-metadata">

**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 8\
**Last updated:** [January 9, 2023, 11:14pm UTC](https://discourse.julialang.org/t/find-dataframe-row-with-missing-values-present/92728 "2023-01-09T23:14:47Z")

</div>

I am trying to find a row in a dataframe column that has missing values as well. As an example the following code without the missing value works: julia\> df = DataFrame(name=\["a", "b", "c"\], value=\[1,2,3\]) 3×2 DataFram…

---

## [Calling chemical kinetics solvers like CHEMKIN or Cantera from Julia](https://discourse.julialang.org/t/calling-chemical-kinetics-solvers-like-chemkin-or-cantera-from-julia/50568)

<div class="topic-metadata">

**Author:** [@R\_Surya\_Narayan](https://discourse.julialang.org/u/R_Surya_Narayan)\
**Replies:** 2\
**Last updated:** [January 9, 2023, 9:46pm UTC](https://discourse.julialang.org/t/calling-chemical-kinetics-solvers-like-chemkin-or-cantera-from-julia/50568 "2023-01-09T21:46:12Z")

</div>

Hello Everyone. I am relatively new to Julia and I am using it to solve a chemically-reacting flow problem that requires extensive reaction-rate and species thermodynamic-data. I came across one such open-source software…

---

## [Help implementing parallelism with readbytes!](https://discourse.julialang.org/t/help-implementing-parallelism-with-readbytes/92672)

<div class="topic-metadata">

**Author:** [@CodeGodz](https://discourse.julialang.org/u/CodeGodz)\
**Replies:** 9\
**Last updated:** [January 9, 2023, 9:44pm UTC](https://discourse.julialang.org/t/help-implementing-parallelism-with-readbytes/92672 "2023-01-09T21:44:08Z")

</div>

I have to read some TBs of data and I want to read a 10-50GB chunk using readbytes! and process it. Since processing the chunk takes longer than reading it it would be a waste to every time wait for the readbytes!. So I…

---

## [Proper way to revise a package under local development](https://discourse.julialang.org/t/proper-way-to-revise-a-package-under-local-development/92730)

<div class="topic-metadata">

**Author:** [@Robert\_Aronoff](https://discourse.julialang.org/u/Robert_Aronoff)\
**Replies:** 1\
**Last updated:** [January 9, 2023, 9:10pm UTC](https://discourse.julialang.org/t/proper-way-to-revise-a-package-under-local-development/92730 "2023-01-09T21:10:45Z")

</div>

Am a bit turned around on appropriate methodology. I am developing a package on my local machine. Created the package structure with PkgTemplates, moved the folder out of dev to a more convenient location, went in to th…

---

## [10-15 minute TTFP with Plots.jl... Please help](https://discourse.julialang.org/t/10-15-minute-ttfp-with-plots-jl-please-help/92636)

<div class="topic-metadata">

**Author:** [@Lilith](https://discourse.julialang.org/u/Lilith)\
**Replies:** 55\
**Last updated:** [January 9, 2023, 8:36pm UTC](https://discourse.julialang.org/t/10-15-minute-ttfp-with-plots-jl-please-help/92636 "2023-01-09T20:36:41Z")

</div>

TLDR: I spend half my day staring at Precompiling project... I hear people talking a lot about improvements in time to first plot, but I’m not seeing it. My TTPF is still on the order of 10-15 minutes. This is the test …

---

## [Ordinal Indexing as a Language Feature](https://discourse.julialang.org/t/ordinal-indexing-as-a-language-feature/91970)

<div class="topic-metadata">

**Author:** [@ParadaCarleton](https://discourse.julialang.org/u/ParadaCarleton)\
**Replies:** 25\
**Last updated:** [January 9, 2023, 7:45pm UTC](https://discourse.julialang.org/t/ordinal-indexing-as-a-language-feature/91970 "2023-01-09T19:45:15Z")

</div>

So, I just had an interesting idea for a 2.0 redesign that could kill the problems with Dictionaries, array labeling, and OffsetArrays with one stone. Someone recently put out a very nice package which distinguishes betw…

[Previous page](https://discourse.julialang.org/latest.md?page=815)

[Next page](https://discourse.julialang.org/latest.md?page=817)