# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=273

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**Page:** 274

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## [What is "incremental compilation" and what does it mean for it to be "broken"?](https://discourse.julialang.org/t/what-is-incremental-compilation-and-what-does-it-mean-for-it-to-be-broken/100956)

<div class="topic-metadata">

**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 16\
**Last updated:** [July 2, 2023, 9:30am UTC](https://discourse.julialang.org/t/what-is-incremental-compilation-and-what-does-it-mean-for-it-to-be-broken/100956 "2023-07-02T09:30:29Z")

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I’ve seen posts talking about a warning “incremental compilation may be fatally broken for this module”. Sometimes it’s not clear why, sometimes it happens because they overwrote a method in a package. What does this mea…

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## [Coefficients on Univariate Polynomial Ring](https://discourse.julialang.org/t/coefficients-on-univariate-polynomial-ring/101071)

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**Author:** [@blociss](https://discourse.julialang.org/u/blociss)\
**Replies:** 0\
**Last updated:** [July 2, 2023, 8:48am UTC](https://discourse.julialang.org/t/coefficients-on-univariate-polynomial-ring/101071 "2023-07-02T08:48:24Z")

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Let R,q=QQ\["q"\] and S,(x,q)=QQ\["x","q"\] two polynomial Ring. let p = q^4 - 2\*q^2 + q + 1 defined in R and S. collect(coefficients(p)) in R give me 5-element Vector{QQFieldElem}: 1 1 -2 0 1 while in the ri…

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## [DataDrivenDiffEq.jl: LoadError upon creating DataDrivenProblem from solution object](https://discourse.julialang.org/t/datadrivendiffeq-jl-loaderror-upon-creating-datadrivenproblem-from-solution-object/101065)

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**Author:** [@AlbertEmil](https://discourse.julialang.org/u/AlbertEmil)\
**Replies:** 1\
**Last updated:** [July 2, 2023, 7:29am UTC](https://discourse.julialang.org/t/datadrivendiffeq-jl-loaderror-upon-creating-datadrivenproblem-from-solution-object/101065 "2023-07-02T07:29:14Z")

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I just started to make my first steps with DataDrivenDiffEq.jl and was able to reproduce the introductory example from the docs without any problems. However, I stumbled upon two very similar errors when I try to adapt …

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## [\`component\_centroids\` did not recognize \`Matrix{Int32}\`](https://discourse.julialang.org/t/component-centroids-did-not-recognize-matrix-int32/101067)

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**Author:** [@Adam\_Page](https://discourse.julialang.org/u/Adam_Page)\
**Replies:** 1\
**Last updated:** [July 2, 2023, 3:17am UTC](https://discourse.julialang.org/t/component-centroids-did-not-recognize-matrix-int32/101067 "2023-07-02T03:17:18Z")

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I’m new to Julia. I was trying to execute center = component\_centroids(cq)\[2:end\] where cq is of type Matrix{Int32}, but got the following error: MethodError: no method matching component\_centroids(::Matrix{Int32}) Clo…

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## [Clang Edit Requirements](https://discourse.julialang.org/t/clang-edit-requirements/101031)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 1\
**Last updated:** [July 2, 2023, 12:52am UTC](https://discourse.julialang.org/t/clang-edit-requirements/101031 "2023-07-02T00:52:19Z")

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I did some work on making a Julia interface for the MCC172. It has a c language library which I wrapped into Julia code. Then I came across Clang and thought I would try it and compare. For the simpler functions I get…

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## [RCall UndefVarError](https://discourse.julialang.org/t/rcall-undefvarerror/101027)

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**Author:** [@eweiss](https://discourse.julialang.org/u/eweiss)\
**Replies:** 4\
**Last updated:** [July 1, 2023, 9:29pm UTC](https://discourse.julialang.org/t/rcall-undefvarerror/101027 "2023-07-01T21:29:53Z")

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I’m running the REPL with this code: using RCall function demo() @rlibrary tidyquant R"tidyquant::tq\_index(‘DOW’)" end And I get the error message: Warning: RCall.jl: Registered S3 method overwritten by ‘quantmod’…

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## [Why are there two websites for packages?](https://discourse.julialang.org/t/why-are-there-two-websites-for-packages/101058)

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**Author:** [@The\_Mastermage](https://discourse.julialang.org/u/The_Mastermage)\
**Replies:** 3\
**Last updated:** [July 1, 2023, 8:45pm UTC](https://discourse.julialang.org/t/why-are-there-two-websites-for-packages/101058 "2023-07-01T20:45:44Z")

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Always when i want to search for packages in Julia I find myself struggling which one to search: https://juliahub.com/ui/Packages https://juliapackages.com/ Can someone tell me which one is the one to use? I would als…

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## [Fast recursion with big rationals](https://discourse.julialang.org/t/fast-recursion-with-big-rationals/101023)

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**Author:** [@Denis\_Ivanov](https://discourse.julialang.org/u/Denis_Ivanov)\
**Replies:** 4\
**Last updated:** [July 1, 2023, 3:56pm UTC](https://discourse.julialang.org/t/fast-recursion-with-big-rationals/101023 "2023-07-01T15:56:24Z")

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Hi! Now I’m doing one task for OEIS. In particular, I need to implement a fast algorithm for finding egyptian fractions of shortest length. There is the next algorithm for to find just the shortest length: If there…

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## [How to get methods of functor?](https://discourse.julialang.org/t/how-to-get-methods-of-functor/101050)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 1\
**Last updated:** [July 1, 2023, 1:04pm UTC](https://discourse.julialang.org/t/how-to-get-methods-of-functor/101050 "2023-07-01T13:04:51Z")

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How to get methods of functor? julia\> foo() = 2; julia\> foo(x) = x + 2; julia\> methods(foo) # 2 methods for generic function "foo": \[1\] foo() in Main at REPL\[21\]:1 \[2\] foo(x) in Main at REPL\[22\]:1 julia\> struct Foo x en…

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## [Convert (N)D Array to (N-2)D Array of SMatrix elements](https://discourse.julialang.org/t/convert-n-d-array-to-n-2-d-array-of-smatrix-elements/85555)

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**Author:** [@andrewkhardy](https://discourse.julialang.org/u/andrewkhardy)\
**Replies:** 3\
**Last updated:** [July 1, 2023, 10:45am UTC](https://discourse.julialang.org/t/convert-n-d-array-to-n-2-d-array-of-smatrix-elements/85555 "2023-07-01T10:45:28Z")

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I want to do matrix inversion on a stack of matrices, based on this post. I’m having difficulty recasting the arrays though. In my case, the array will come as data or an input to a function, but here is a minimal exampl…

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## [How to pass name of macro argument into result struct parameter](https://discourse.julialang.org/t/how-to-pass-name-of-macro-argument-into-result-struct-parameter/101049)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 1\
**Last updated:** [July 1, 2023, 10:36am UTC](https://discourse.julialang.org/t/how-to-pass-name-of-macro-argument-into-result-struct-parameter/101049 "2023-07-01T10:36:47Z")

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Hello, please help to pass name of macro argument into result struct parameter struct Foo{x} end macro foo(x) return esc(:($x = Foo{QuoteNode($x)})) # ??? end @macroexpand @foo x # need - \> # x = Foo{:x} x = …

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## [Strange --- seemingly out-of-bounds access --- bug in Julia v1.6](https://discourse.julialang.org/t/strange-seemingly-out-of-bounds-access-bug-in-julia-v1-6/101041)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 1\
**Last updated:** [July 1, 2023, 4:42am UTC](https://discourse.julialang.org/t/strange-seemingly-out-of-bounds-access-bug-in-julia-v1-6/101041 "2023-07-01T04:42:37Z")

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Using Julia v1.6.7, I obtain julia\> using LinearAlgebra, FillArrays julia\> for (dv, ev) in ((Fill(2,3), Fill(6,2)), (Zeros(2), Zeros(1))) display(Tridiagonal(ev, dv, ev)) end 3×3…

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## [A question about install GLMakie](https://discourse.julialang.org/t/a-question-about-install-glmakie/101037)

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**Author:** [@yu\_xiong](https://discourse.julialang.org/u/yu_xiong)\
**Replies:** 1\
**Last updated:** [July 1, 2023, 1:59am UTC](https://discourse.julialang.org/t/a-question-about-install-glmakie/101037 "2023-07-01T01:59:11Z")

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when I install GLMakie，A question ERROR: LoadError: InitError: could not load library “C:\\Users\\xiongyu.julia\\artifacts\\a9f1da02e36476372227c9067f101c4385fc3f38\\bin\\libqhull\_r.dll” %1 is not a valid Win32 application.

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## [Overview of ODE solvers for complex-valued ODE](https://discourse.julialang.org/t/overview-of-ode-solvers-for-complex-valued-ode/101017)

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**Author:** [@dnldlg](https://discourse.julialang.org/u/dnldlg)\
**Replies:** 1\
**Last updated:** [June 30, 2023, 6:01pm UTC](https://discourse.julialang.org/t/overview-of-ode-solvers-for-complex-valued-ode/101017 "2023-06-30T18:01:44Z")

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Is there an overview such as this page that lists all solver algorithms that are suitable for complex-valued ODEs?

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## [How to run OhMyREPL.jl with startup.jl?](https://discourse.julialang.org/t/how-to-run-ohmyrepl-jl-with-startup-jl/101002)

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**Author:** [@Hugo](https://discourse.julialang.org/u/Hugo)\
**Replies:** 4\
**Last updated:** [June 30, 2023, 5:54pm UTC](https://discourse.julialang.org/t/how-to-run-ohmyrepl-jl-with-startup-jl/101002 "2023-06-30T17:54:13Z")

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Hello, all I decided to add the following piece of code to my startup.jl file to have Revise.jl and OhMyREPL.jl run from the get-go as I open the application import Pkg let pkgs = \["Revise", "OhMyREPL"\] for pkg…

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## [How to determine explicit derivative using variables with known derivatives](https://discourse.julialang.org/t/how-to-determine-explicit-derivative-using-variables-with-known-derivatives/101014)

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**Author:** [@Thomas\_Van\_Giel](https://discourse.julialang.org/u/Thomas_Van_Giel)\
**Replies:** 3\
**Last updated:** [June 30, 2023, 2:40pm UTC](https://discourse.julialang.org/t/how-to-determine-explicit-derivative-using-variables-with-known-derivatives/101014 "2023-06-30T14:40:53Z")

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I want to check some Lyapunov functions for a dynamical system. In order to do that, I have the variables in my system: n1(t) - n4(t), and m(t), which define a set of coupled ODEs. I declare a (wannabe) Lyapunov function…

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## [Plotting points on a plot with subplots](https://discourse.julialang.org/t/plotting-points-on-a-plot-with-subplots/100993)

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**Author:** [@maoc](https://discourse.julialang.org/u/maoc)\
**Replies:** 1\
**Last updated:** [June 30, 2023, 2:25pm UTC](https://discourse.julialang.org/t/plotting-points-on-a-plot-with-subplots/100993 "2023-06-30T14:25:50Z")

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I have a rather long time series. For example, T = mx100. I can break this long series into m subplots. For example: using Plots # number of supblots m=5 # Size of my time series T = m\*100 # Time t\_ = 1:T t\_ = reshap…

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## [Need help on Manopt](https://discourse.julialang.org/t/need-help-on-manopt/100867)

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**Author:** [@dgagnon](https://discourse.julialang.org/u/dgagnon)\
**Replies:** 13\
**Last updated:** [June 30, 2023, 12:08pm UTC](https://discourse.julialang.org/t/need-help-on-manopt/100867 "2023-06-30T12:08:27Z")

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Hello I must find a maximum likelihood estimator for a distribution I have designed. But, I can’t have an explicit expression for it. Looking at another thread: Maximum likelihood for t-distribution by gradient descent,…

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## [How to convert Vector{Any} to a narrower type?](https://discourse.julialang.org/t/how-to-convert-vector-any-to-a-narrower-type/60376)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 11\
**Last updated:** [June 30, 2023, 11:31am UTC](https://discourse.julialang.org/t/how-to-convert-vector-any-to-a-narrower-type/60376 "2023-06-30T11:31:05Z")

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Consider the following Julia code julia\> a = Any\[1, 2, 3.0\] 3-element Vector{Any}: 1 2 3.0 julia\> map(x-\>x, a) 3-element Vector{Real}: 1 2 3.0 Here I abused map to convert an array of Any to the narrowest type R…

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## [Error happens when you try to execute command ENV\["R\_HOME"\]](https://discourse.julialang.org/t/error-happens-when-you-try-to-execute-command-env-r-home/100863)

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**Author:** [@Faraz564](https://discourse.julialang.org/u/Faraz564)\
**Replies:** 4\
**Last updated:** [June 30, 2023, 10:52am UTC](https://discourse.julialang.org/t/error-happens-when-you-try-to-execute-command-env-r-home/100863 "2023-06-30T10:52:01Z")

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Hi Everyone I am using Julia in R Studio. I have encountered the problem of with installing julia.setup(Install=True). This synatax creat error. Please see them below in picture. I would appreciate your suggestion.

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## [BinaryBuilder: ERROR: LoadError: Cannot continue with unsatisfied build products!](https://discourse.julialang.org/t/binarybuilder-error-loaderror-cannot-continue-with-unsatisfied-build-products/100992)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 14\
**Last updated:** [June 30, 2023, 10:35am UTC](https://discourse.julialang.org/t/binarybuilder-error-loaderror-cannot-continue-with-unsatisfied-build-products/100992 "2023-06-30T10:35:59Z")

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I’m trying to build some binaries for several platforms using BinaryBuilder. The wizard runs nicely, and I get no errors. Yet, when I finish the wizard, the binaries are not save anywhere, it seems. The build\_tarballs.j…

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## [Web scraping of GCN NASA circulars TEXT](https://discourse.julialang.org/t/web-scraping-of-gcn-nasa-circulars-text/100809)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 16\
**Last updated:** [June 30, 2023, 10:02am UTC](https://discourse.julialang.org/t/web-scraping-of-gcn-nasa-circulars-text/100809 "2023-06-30T10:02:33Z")

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I want to scrap GCN - Circulars for optical events. For example i want to get following information this web page :blush: and similarly for other web pages containing optical events and store in ccv or excel form…

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## [Inconsistency between @async warning and its usage in documentation](https://discourse.julialang.org/t/inconsistency-between-async-warning-and-its-usage-in-documentation/100978)

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**Author:** [@algunion](https://discourse.julialang.org/u/algunion)\
**Replies:** 2\
**Last updated:** [June 30, 2023, 9:37am UTC](https://discourse.julialang.org/t/inconsistency-between-async-warning-and-its-usage-in-documentation/100978 "2023-06-30T09:37:29Z")

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Recently I was answering an @async related question, and I remembered a documentation warning against @async usage. After checking that out, it was still there: It is strongly encouraged to favor Threads.@spawn over @a…

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## [The scale-change of "cgrad" is invalidated when colorschemes are jointed](https://discourse.julialang.org/t/the-scale-change-of-cgrad-is-invalidated-when-colorschemes-are-jointed/100966)

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**Author:** [@Fluorite-Erbite](https://discourse.julialang.org/u/Fluorite-Erbite)\
**Replies:** 2\
**Last updated:** [June 30, 2023, 4:33am UTC](https://discourse.julialang.org/t/the-scale-change-of-cgrad-is-invalidated-when-colorschemes-are-jointed/100966 "2023-06-30T04:33:09Z")

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Julia 1.9.0 downloaded from the official (Sorry for my poor English) I want to join 2 colorschemes, before which each scale is change (:log). Example, cs1 = reverse( cgrad( palette( \[:red, :orange, :yellow, :lawngree…

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## [Differences between extending \`Base.show\` and \`Base.showerror\` for a custom exception type in Julia?](https://discourse.julialang.org/t/differences-between-extending-base-show-and-base-showerror-for-a-custom-exception-type-in-julia/101003)

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**Author:** [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Replies:** 1\
**Last updated:** [June 29, 2023, 11:14pm UTC](https://discourse.julialang.org/t/differences-between-extending-base-show-and-base-showerror-for-a-custom-exception-type-in-julia/101003 "2023-06-29T23:14:08Z")

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I’m working on a Julia project where I have defined a custom exception type like this: struct XXXError \<: Exception e::String end Now, I want to customize how instances of this exception type are displayed. I under…

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## [Computing expectation of nonlinear function of multinomial logit](https://discourse.julialang.org/t/computing-expectation-of-nonlinear-function-of-multinomial-logit/80575)

<div class="topic-metadata">

**Author:** [@samerb](https://discourse.julialang.org/u/samerb)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 6:03pm UTC](https://discourse.julialang.org/t/computing-expectation-of-nonlinear-function-of-multinomial-logit/80575 "2023-06-29T18:03:25Z")

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Suppose I have constants \\{\\delta\_j\\}\_{j \\in J} and have random variables \\{\\varepsilon\_j\\}\_{j\\in J} distributed iid according to type I extreme value distribution as in a standard multinomial logit model. Let F: \\mathbb…

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## [Getting IJulia to work inside of a mamba venv](https://discourse.julialang.org/t/getting-ijulia-to-work-inside-of-a-mamba-venv/100977)

<div class="topic-metadata">

**Author:** [@anon56682678](https://discourse.julialang.org/u/anon56682678)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 5:27pm UTC](https://discourse.julialang.org/t/getting-ijulia-to-work-inside-of-a-mamba-venv/100977 "2023-06-29T17:27:09Z")

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I am having trouble installing IJulia in Julia 1.9.1 inside a mamba environment. The crux of the issue seems to be the compiler not being able to find MbedTLS even though it is installed Looking for: \['mbedtls'\] conda-…

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## [Lazy Constraints on MIP problems](https://discourse.julialang.org/t/lazy-constraints-on-mip-problems/100969)

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**Author:** [@Ignacio](https://discourse.julialang.org/u/Ignacio)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 12:18pm UTC](https://discourse.julialang.org/t/lazy-constraints-on-mip-problems/100969 "2023-06-29T12:18:42Z")

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Hello all, I am trying trying to solve the following MIP with the Xpress solver (and I’ve also tried it with the GLPK solver) with lazy constraint. Variables of interest are x and y (non-integer), integer variable z is …

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## [Backward SDE StochasticDiffEq](https://discourse.julialang.org/t/backward-sde-stochasticdiffeq/100952)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 11:18am UTC](https://discourse.julialang.org/t/backward-sde-stochasticdiffeq/100952 "2023-06-29T11:18:01Z")

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Hello, I am interested in solving backward SDEs as in these papers (https://arxiv.org/pdf/2011.13456.pdf, https://papers.nips.cc/paper/2021/file/0a9fdbb17feb6ccb7ec405cfb85222c4-Paper.pdf). They talk about standard Wien…

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## [Heat-diffusion equation boundary condition](https://discourse.julialang.org/t/heat-diffusion-equation-boundary-condition/100592)

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**Author:** [@Reza\_AO](https://discourse.julialang.org/u/Reza_AO)\
**Replies:** 7\
**Last updated:** [June 29, 2023, 8:48am UTC](https://discourse.julialang.org/t/heat-diffusion-equation-boundary-condition/100592 "2023-06-29T08:48:39Z")

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Hi I want to solve a 1 dimensional heat diffusion equation. At the right side of my domain I got the convective boundary condition; #Tamb, Kl,h are constants h \* (T(t, Le) - Tamb) - kl \* Dx(T(t, 0)) ~ 0 When I solv…

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