# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1982

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

**Page:** 1983

---

## [Exp() of nonsquare matrix](https://discourse.julialang.org/t/exp-of-nonsquare-matrix/25036)

<div class="topic-metadata">

**Author:** [@hytonwons](https://discourse.julialang.org/u/hytonwons)\
**Replies:** 3\
**Last updated:** [June 7, 2019, 8:02am UTC](https://discourse.julialang.org/t/exp-of-nonsquare-matrix/25036 "2019-06-07T08:02:46Z")

</div>

Hi, I ran into an issue on exp() of a matrix. Here is a minimal reproducible example, and I’m using Julia 1.0.3: using LinearAlgebra exp(Matrix(1.0I, 2, 1)) The error I got is: DimensionMismatch("matrix is not squa…

---

## [Subtype vs Abstract type in function definition](https://discourse.julialang.org/t/subtype-vs-abstract-type-in-function-definition/25030)

<div class="topic-metadata">

**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 1\
**Last updated:** [June 7, 2019, 3:26am UTC](https://discourse.julialang.org/t/subtype-vs-abstract-type-in-function-definition/25030 "2019-06-07T03:26:59Z")

</div>

Is there a difference between these two functions? Is it just a coincidence/fluke of Julia syntax, or is there a deeper meaning that separates them or reason for both of them to be permitted. function f(a::AbstractVecto…

---

## [About operators & some other questions & possible suggestions](https://discourse.julialang.org/t/about-operators-some-other-questions-possible-suggestions/24341)

<div class="topic-metadata">

**Author:** [@B.Vangod](https://discourse.julialang.org/u/B.Vangod)\
**Replies:** 8\
**Last updated:** [June 7, 2019, 1:35am UTC](https://discourse.julialang.org/t/about-operators-some-other-questions-possible-suggestions/24341 "2019-06-07T01:35:53Z")

</div>

Hi. I am new to Julia and have enjoyed it so far. What a beautiful language. I have not made anything special or serious with it yet, but was playing with it and was getting used to it. I have used C and C-like language…

---

## [Starting Cuda programming with Julia](https://discourse.julialang.org/t/starting-cuda-programming-with-julia/25009)

<div class="topic-metadata">

**Author:** [@wiktorkujawa](https://discourse.julialang.org/u/wiktorkujawa)\
**Replies:** 3\
**Last updated:** [June 7, 2019, 1:05am UTC](https://discourse.julialang.org/t/starting-cuda-programming-with-julia/25009 "2019-06-07T01:05:32Z")

</div>

Hi, I want to start programming with CUDA language. I just bought new notebook with NVIDIA GeForce GTX 1050 graphic card and windows 10 system. I personally use Linux mint, so I want to install it on my new notebook. I r…

---

## [Error with Cairo and Fontconfig](https://discourse.julialang.org/t/error-with-cairo-and-fontconfig/25025)

<div class="topic-metadata">

**Author:** [@B.Vangod](https://discourse.julialang.org/u/B.Vangod)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 11:49pm UTC](https://discourse.julialang.org/t/error-with-cairo-and-fontconfig/25025 "2019-06-06T23:49:41Z")

</div>

I saw a few links that may have given me a solution, but in the end it was not really effective for me. I hope this is the right forum to post this. I’ve been using DataFrames, DataFramesMeta, Gadfly, CSV (and sometimes…

---

## [Plots Ticks Axis Override](https://discourse.julialang.org/t/plots-ticks-axis-override/25026)

<div class="topic-metadata">

**Author:** [@fer](https://discourse.julialang.org/u/fer)\
**Replies:** 0\
**Last updated:** [June 6, 2019, 9:23pm UTC](https://discourse.julialang.org/t/plots-ticks-axis-override/25026 "2019-06-06T21:23:01Z")

</div>

I am using the Plots library and I create plots as attached to this post. The y-ticks label for instance of the plot of “x4” are not nice and I would like to find an automatic way to arrange them (I created this plots i…

---

## [How to use CairoMakie?](https://discourse.julialang.org/t/how-to-use-cairomakie/25001)

<div class="topic-metadata">

**Author:** [@cserteGT3](https://discourse.julialang.org/u/cserteGT3)\
**Replies:** 6\
**Last updated:** [June 6, 2019, 9:17pm UTC](https://discourse.julialang.org/t/how-to-use-cairomakie/25001 "2019-06-06T21:17:55Z")

</div>

I can’t figure out, how to use Makie with CairoMakie and neither found tutorials on it. What I tried: (RealTimePlot-julia) pkg\> st Status \`C:\\Users\\EMI\\Documents\\cstamas\_SVN\\cstamas\\JuliaRobotics\\RealTimePlot-julia…

---

## [How can I shade an area under a curve between two lines?](https://discourse.julialang.org/t/how-can-i-shade-an-area-under-a-curve-between-two-lines/24897)

<div class="topic-metadata">

**Author:** [@Alessandro\_Vivas](https://discourse.julialang.org/u/Alessandro_Vivas)\
**Replies:** 5\
**Last updated:** [June 6, 2019, 8:26pm UTC](https://discourse.julialang.org/t/how-can-i-shade-an-area-under-a-curve-between-two-lines/24897 "2019-06-06T20:26:27Z")

</div>

I am plotting a normal curve and I want shaded some areas in this curve. I want to shaded to values minor than -1.96 e greater than 1.96. I tried some options: fill and fill area but I didn’t get sucess. x = rand( Norma…

---

## [Calling a package function with a parallelized for loop](https://discourse.julialang.org/t/calling-a-package-function-with-a-parallelized-for-loop/24986)

<div class="topic-metadata">

**Author:** [@bigoten](https://discourse.julialang.org/u/bigoten)\
**Replies:** 2\
**Last updated:** [June 6, 2019, 8:17pm UTC](https://discourse.julialang.org/t/calling-a-package-function-with-a-parallelized-for-loop/24986 "2019-06-06T20:17:39Z")

</div>

I want to run some code in parallel, however I found a strange behavior that I would like to understand. Here is a small working example: using Random; using Statistics; using Distributed; using SharedArrays; nprocs()…

---

## [Is there a way to debug an Nlopt optimization](https://discourse.julialang.org/t/is-there-a-way-to-debug-an-nlopt-optimization/24289)

<div class="topic-metadata">

**Author:** [@CPPhysics](https://discourse.julialang.org/u/CPPhysics)\
**Replies:** 27\
**Last updated:** [June 6, 2019, 6:31pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-debug-an-nlopt-optimization/24289 "2019-06-06T18:31:08Z")

</div>

I am trying to debug my code with the Juno debugger, and I would like to run part of the optimization line by line, however when I try to “@enter”, the REPL tells me I can only call that with a function. Is there any way…

---

## [Using Module names for dispatch](https://discourse.julialang.org/t/using-module-names-for-dispatch/25010)

<div class="topic-metadata">

**Author:** [@pablosanjose](https://discourse.julialang.org/u/pablosanjose)\
**Replies:** 6\
**Last updated:** [June 6, 2019, 5:28pm UTC](https://discourse.julialang.org/t/using-module-names-for-dispatch/25010 "2019-06-06T17:28:58Z")

</div>

I’m working on a metapackage (HermitianDiagonalization.jl) that implements a bunch of methods based on the functionality of some third-party packages (Arpack, ArnoldiMethod, etc…), provided they have been loaded by the u…

---

## [Semi-continuous variables: JuMP and Cplex solver](https://discourse.julialang.org/t/semi-continuous-variables-jump-and-cplex-solver/24966)

<div class="topic-metadata">

**Author:** [@bienpierre](https://discourse.julialang.org/u/bienpierre)\
**Replies:** 2\
**Last updated:** [June 6, 2019, 4:08pm UTC](https://discourse.julialang.org/t/semi-continuous-variables-jump-and-cplex-solver/24966 "2019-06-06T16:08:17Z")

</div>

Hello, I have a semi-continuous variable, the domain is {0} U \[l,u\]. Example is: using JuMP using CPLEX MyModel = Model(with\_optimizer(CPLEX.Optimizer)) @variable(MyModel, zz) @constraint(MyModel, zz in MOI.Semicontin…

---

## [Flux - cannot add package to Julia 1.1](https://discourse.julialang.org/t/flux-cannot-add-package-to-julia-1-1/24993)

<div class="topic-metadata">

**Author:** [@mrVeng](https://discourse.julialang.org/u/mrVeng)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 2:10pm UTC](https://discourse.julialang.org/t/flux-cannot-add-package-to-julia-1-1/24993 "2019-06-06T14:10:07Z")

</div>

Hi guys, I am new to Julia and installed some packages successfully already, I am working via Juno in the Atom ide and downloaded JuliaPRO 1.1 . I would like to add Flux as well, but get an error, I added a screenshot …

---

## [Normalization of histograms](https://discourse.julialang.org/t/normalization-of-histograms/25007)

<div class="topic-metadata">

**Author:** [@woutersj](https://discourse.julialang.org/u/woutersj)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 1:22pm UTC](https://discourse.julialang.org/t/normalization-of-histograms/25007 "2019-06-06T13:22:40Z")

</div>

This used to work in v0.6.3: using StatsBase normalize(fit(Histogram,rand(100),closed=:left)) In v1.1.0 I get UndefVarError: normalize not defined. Is this a bug or has the syntax changed?

---

## [The art of giving and receiving code reviews](https://discourse.julialang.org/t/the-art-of-giving-and-receiving-code-reviews/25002)

<div class="topic-metadata">

**Author:** [@Datseris](https://discourse.julialang.org/u/Datseris)\
**Replies:** 4\
**Last updated:** [June 6, 2019, 1:16pm UTC](https://discourse.julialang.org/t/the-art-of-giving-and-receiving-code-reviews/25002 "2019-06-06T13:16:46Z")

</div>

Hi All, I just finished participating in the “Reseach Software Engineers” conference in Germany, deRSE19 . From the conference I took home 2 important messages, the first one I will share in this post (and the second to…

---

## [Efficiently Calculate Matrices Defined Recursively](https://discourse.julialang.org/t/efficiently-calculate-matrices-defined-recursively/25006)

<div class="topic-metadata">

**Author:** [@Joseph\_Saia](https://discourse.julialang.org/u/Joseph_Saia)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 12:48pm UTC](https://discourse.julialang.org/t/efficiently-calculate-matrices-defined-recursively/25006 "2019-06-06T12:48:11Z")

</div>

In my work I frequently have to calculate a long sequence (about N=10^6) of small matrices (about 3x3) that are defined recursively like X\_t = f(X\_{t-1}). The object of interest is the entire chain of matrices so I need …

---

## [Loading image folder](https://discourse.julialang.org/t/loading-image-folder/24999)

<div class="topic-metadata">

**Author:** [@Deanodirector](https://discourse.julialang.org/u/Deanodirector)\
**Replies:** 0\
**Last updated:** [June 6, 2019, 8:58am UTC](https://discourse.julialang.org/t/loading-image-folder/24999 "2019-06-06T08:58:41Z")

</div>

Hello, sorry for the basic question. I know how to load an image in FileIO but how do I load a folder and reshape into an array to use as a flux input? Many thanks

---

## [Waiting for lock on pidfile .jlassetregistry.lock](https://discourse.julialang.org/t/waiting-for-lock-on-pidfile-jlassetregistry-lock/24962)

<div class="topic-metadata">

**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 9:23am UTC](https://discourse.julialang.org/t/waiting-for-lock-on-pidfile-jlassetregistry-lock/24962 "2019-06-06T09:23:55Z")

</div>

A module of mine is using several other modules/packages. When I load my module @everywhere I get infos about “waiting for lock on pidfile .jlassetregistry.lock”. Can someone help me understand this? Can I find out whi…

---

## [How to install matlab in julia and how to occupy it](https://discourse.julialang.org/t/how-to-install-matlab-in-julia-and-how-to-occupy-it/24994)

<div class="topic-metadata">

**Author:** [@GERSON\_EZEQUIEL\_HERN](https://discourse.julialang.org/u/GERSON_EZEQUIEL_HERN)\
**Replies:** 6\
**Last updated:** [June 6, 2019, 8:36am UTC](https://discourse.julialang.org/t/how-to-install-matlab-in-julia-and-how-to-occupy-it/24994 "2019-06-06T08:36:28Z")

</div>

I need Matlab in julia…

---

## [Type defintions of composite types with concrete dimensions](https://discourse.julialang.org/t/type-defintions-of-composite-types-with-concrete-dimensions/24991)

<div class="topic-metadata">

**Author:** [@Volker](https://discourse.julialang.org/u/Volker)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 8:04am UTC](https://discourse.julialang.org/t/type-defintions-of-composite-types-with-concrete-dimensions/24991 "2019-06-06T08:04:35Z")

</div>

Hello, I would like to improve the performance of my code. And now starting to make stable types. Is it possible to create types with a concrete dimension in a struct with other fields of the struct? I know that this is…

---

## [Weird errors installing Julia client and ink](https://discourse.julialang.org/t/weird-errors-installing-julia-client-and-ink/24989)

<div class="topic-metadata">

**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 3\
**Last updated:** [June 6, 2019, 3:56am UTC](https://discourse.julialang.org/t/weird-errors-installing-julia-client-and-ink/24989 "2019-06-06T03:56:16Z")

</div>

Windows 10 here. First I tried the package installer in Atom. That failed (incompatible version of uber-juno 0.2??). Then I got down to the command line and I got: $ apm install ink Installing ink to C:\\Users\\PK\\.atom…

---

## [Configuring MPI.jl to run on XC-40 / KNL with craype and cray-mpich](https://discourse.julialang.org/t/configuring-mpi-jl-to-run-on-xc-40-knl-with-craype-and-cray-mpich/20197)

<div class="topic-metadata">

**Author:** [@frankwillmore](https://discourse.julialang.org/u/frankwillmore)\
**Replies:** 10\
**Last updated:** [June 6, 2019, 2:56am UTC](https://discourse.julialang.org/t/configuring-mpi-jl-to-run-on-xc-40-knl-with-craype-and-cray-mpich/20197 "2019-06-06T02:56:12Z")

</div>

I am attempting to configure the MPI.jl package to run in Julia 1.0.3 on theta, a Cray XC-40/KNL. Cross-compilation has not been an issue, but interfacing to the CrayPE and Cray-MPICH are currently stumping me. I have be…

---

## [How can I evaluate a Julia function with sin/cos as real value?](https://discourse.julialang.org/t/how-can-i-evaluate-a-julia-function-with-sin-cos-as-real-value/24988)

<div class="topic-metadata">

**Author:** [@Nha\_Dinh\_Cao](https://discourse.julialang.org/u/Nha_Dinh_Cao)\
**Replies:** 1\
**Last updated:** [June 6, 2019, 12:39am UTC](https://discourse.julialang.org/t/how-can-i-evaluate-a-julia-function-with-sin-cos-as-real-value/24988 "2019-06-06T00:39:16Z")

</div>

Hi everyone, I have a Julia function like f(x) = x + sin(x), and then I try to type f(2), which returns 2 + sin(2). I think it is great, but is there anything to make it returns a single real number? Thank you. It would…

---

## [Standard streams much slower in Windows than in Linux](https://discourse.julialang.org/t/standard-streams-much-slower-in-windows-than-in-linux/24924)

<div class="topic-metadata">

**Author:** [@mbaz](https://discourse.julialang.org/u/mbaz)\
**Replies:** 4\
**Last updated:** [June 5, 2019, 9:52pm UTC](https://discourse.julialang.org/t/standard-streams-much-slower-in-windows-than-in-linux/24924 "2019-06-05T21:52:21Z")

</div>

While testing Gaston in Windows, I discovered that it was running much slower than in Linux. A simple plot in Windows could take a few seconds, while in Linux it is basically instantaneous. Some tests seemed to point to …

---

## [Can a FunctionWrapper be used with a function that isn't type stable?](https://discourse.julialang.org/t/can-a-functionwrapper-be-used-with-a-function-that-isnt-type-stable/24977)

<div class="topic-metadata">

**Author:** [@danielmatz](https://discourse.julialang.org/u/danielmatz)\
**Replies:** 2\
**Last updated:** [June 5, 2019, 9:36pm UTC](https://discourse.julialang.org/t/can-a-functionwrapper-be-used-with-a-function-that-isnt-type-stable/24977 "2019-06-05T21:36:40Z")

</div>

I’ve been experimenting with using FunctionWrappers.jl. When I try to create a FunctionWrapper for a function that doesn’t have a stable return type, I get a segfault. Is that a limitation of FunctionWrapper, or is tha…

---

## [Failure to precompile packages on ARM](https://discourse.julialang.org/t/failure-to-precompile-packages-on-arm/24974)

<div class="topic-metadata">

**Author:** [@Marco\_Andres\_Bastias](https://discourse.julialang.org/u/Marco_Andres_Bastias)\
**Replies:** 4\
**Last updated:** [June 5, 2019, 9:08pm UTC](https://discourse.julialang.org/t/failure-to-precompile-packages-on-arm/24974 "2019-06-05T21:08:34Z")

</div>

I want to use the julia program to process some images, but the image package does not respond. when i use: julia\> using Images \[ Info: Precompiling Images \[916415d5-f1e6-5110-898d-aaa5f9f070e0\] ERROR: could not load li…

---

## [Postdoc Positions @ LANL USA: Physics-informed machine learning](https://discourse.julialang.org/t/postdoc-positions-lanl-usa-physics-informed-machine-learning/24978)

<div class="topic-metadata">

**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 0\
**Last updated:** [June 5, 2019, 8:49pm UTC](https://discourse.julialang.org/t/postdoc-positions-lanl-usa-physics-informed-machine-learning/24978 "2019-06-05T20:49:55Z")

</div>

The Computational Earth Science Group at Los Alamos National Laboratory (LANL) has immediate openings for Postdoctoral Research Associates with applied math and computational science skills. The postdoctoral research wil…

---

## [Understanding supertypes](https://discourse.julialang.org/t/understanding-supertypes/24971)

<div class="topic-metadata">

**Author:** [@Paul\_McVay](https://discourse.julialang.org/u/Paul_McVay)\
**Replies:** 5\
**Last updated:** [June 5, 2019, 7:08pm UTC](https://discourse.julialang.org/t/understanding-supertypes/24971 "2019-06-05T19:08:18Z")

</div>

I’m a little confused about how supertypes work and the inheritance of methods. Say for example, I define my own type with integer as the supertype. How can I use the integer methods with my type? primitive type MyInt \<:…

---

## [ClickHouse database and Julia](https://discourse.julialang.org/t/clickhouse-database-and-julia/14281)

<div class="topic-metadata">

**Author:** [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Replies:** 4\
**Last updated:** [June 5, 2019, 3:10pm UTC](https://discourse.julialang.org/t/clickhouse-database-and-julia/14281 "2019-06-05T15:10:58Z")

</div>

For the last 3 years, I have been tortured by the slowness of Postgresql, and recently I came across this open source columnar database called clickhouse. The speed is unexpectedly fast, especially when I need to run a l…

---

## [PlotlyJS - Match trace color](https://discourse.julialang.org/t/plotlyjs-match-trace-color/24967)

<div class="topic-metadata">

**Author:** [@rand5](https://discourse.julialang.org/u/rand5)\
**Replies:** 0\
**Last updated:** [June 5, 2019, 2:54pm UTC](https://discourse.julialang.org/t/plotlyjs-match-trace-color/24967 "2019-06-05T14:54:55Z")

</div>

I am using PlotlyJS to plot pairs of traces (raw data and lines of best fit). I’d like for each pair of traces to show as the same color. Is there a way to query the color used in a specific trace in order to reuse it l…

[Previous page](https://discourse.julialang.org/latest.md?page=1981)

[Next page](https://discourse.julialang.org/latest.md?page=1983)