# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1019

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

**Page:** 1020

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## [Julia Makie merge/overlay plots](https://discourse.julialang.org/t/julia-makie-merge-overlay-plots/82228)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 2\
**Last updated:** [June 5, 2022, 5:04pm UTC](https://discourse.julialang.org/t/julia-makie-merge-overlay-plots/82228 "2022-06-05T17:04:36Z")

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Hello, I have two heatmaps that I would like to merge to get the amount of two quantities at once. The idea is that one level is green shaded, the other is red, thus the more the resulting plot is “Cinnamon” the more th…

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## [\[ANN\] Spark.jl, reborn](https://discourse.julialang.org/t/ann-spark-jl-reborn/82275)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 0\
**Last updated:** [June 5, 2022, 3:51pm UTC](https://discourse.julialang.org/t/ann-spark-jl-reborn/82275 "2022-06-05T15:51:14Z")

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I’m pleased to announce a new release of Spark.jl - Julia interface to Apache Spark. Apache Spark is a ubiquitous distributed data processing framework used by thousands of organizations for large scale data engineering…

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## [Add a property to a StructArray](https://discourse.julialang.org/t/add-a-property-to-a-structarray/74450)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 7\
**Last updated:** [June 5, 2022, 2:01pm UTC](https://discourse.julialang.org/t/add-a-property-to-a-structarray/74450 "2022-06-05T14:01:49Z")

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Is it possible to add a property to a StructArray? The following code fails: julia\> using KiteUtils, StructArrays julia\> syslog=demo\_syslog(7) julia\> function Base.getproperty(st::StructArray{SysState}, sym::Symbol) …

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## [Intermittent type inference calls during method evaluation](https://discourse.julialang.org/t/intermittent-type-inference-calls-during-method-evaluation/82241)

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**Author:** [@rikh](https://discourse.julialang.org/u/rikh)\
**Replies:** 2\
**Last updated:** [June 5, 2022, 10:41am UTC](https://discourse.julialang.org/t/intermittent-type-inference-calls-during-method-evaluation/82241 "2022-06-05T10:41:14Z")

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When looking through a first call for a longish method via StatProfilerHTML.jl, I see some type inference happening during the method body evaluation: (This is in Julia 1.8-rc1.) I think that this is caused by the m…

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## [Upgrading Julia for GMT.jl users](https://discourse.julialang.org/t/upgrading-julia-for-gmt-jl-users/82223)

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**Author:** [@Leon6](https://discourse.julialang.org/u/Leon6)\
**Replies:** 6\
**Last updated:** [June 5, 2022, 1:10pm UTC](https://discourse.julialang.org/t/upgrading-julia-for-gmt-jl-users/82223 "2022-06-05T13:10:26Z")

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What is the best way to upgrade Julia when you have the GMT.jl package installed? I’m on Mac OS (Intel Processor). It happened a few times that after upgrading to a newer version of Julia, I can no longer use my GMT.jl.…

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## [How to display multiple plot windows?](https://discourse.julialang.org/t/how-to-display-multiple-plot-windows/82246)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [June 5, 2022, 10:59am UTC](https://discourse.julialang.org/t/how-to-display-multiple-plot-windows/82246 "2022-06-05T10:59:07Z")

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How can I display multiple plot windows at the same time? I tried: using Plots x=1:0.1:100 y1=sin.(x) y2=cos.(x) p1 = plot(x,y1) p2 = plot(x,y2) display(p1) display(p2) But I always see only the last plot, not two…

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## ['Parallel' Feature in Flux works with '+' but not '\*'](https://discourse.julialang.org/t/parallel-feature-in-flux-works-with-but-not/82264)

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**Author:** [@compleat](https://discourse.julialang.org/u/compleat)\
**Replies:** 3\
**Last updated:** [June 5, 2022, 10:38am UTC](https://discourse.julialang.org/t/parallel-feature-in-flux-works-with-but-not/82264 "2022-06-05T10:38:39Z")

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The ‘Parallel’ feature for defining network architectures in Flux is very handy and includes the ‘vcat’ and ‘+’ operations. I tried the ‘\*’ (multiplication) operator but it didn’t work for me. Or is there a way to get …

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## [Fuzzy testing](https://discourse.julialang.org/t/fuzzy-testing/82266)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 0\
**Last updated:** [June 5, 2022, 10:11am UTC](https://discourse.julialang.org/t/fuzzy-testing/82266 "2022-06-05T10:11:40Z")

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Hi all :slight\_smile: Quick question: is there a good fuzzy testing pkg? What are the experiences? Cheers

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## [Decoding protobuf message from mapbox API, using ProtoBuf.jl](https://discourse.julialang.org/t/decoding-protobuf-message-from-mapbox-api-using-protobuf-jl/82261)

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**Author:** [@captchanjack1](https://discourse.julialang.org/u/captchanjack1)\
**Replies:** 1\
**Last updated:** [June 5, 2022, 8:34am UTC](https://discourse.julialang.org/t/decoding-protobuf-message-from-mapbox-api-using-protobuf-jl/82261 "2022-06-05T08:34:35Z")

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Hi, I’m new to the world of protocol buffers, looking for some guidance here. I have a fairly simple use case which is to decode protobuf messages from the mapbox API into GeoJSON format. How would I approach this pro…

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## [Mass constraints for ApproxFun BVP system solver](https://discourse.julialang.org/t/mass-constraints-for-approxfun-bvp-system-solver/82257)

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**Author:** [@Jack\_hues](https://discourse.julialang.org/u/Jack_hues)\
**Replies:** 0\
**Last updated:** [June 5, 2022, 3:29am UTC](https://discourse.julialang.org/t/mass-constraints-for-approxfun-bvp-system-solver/82257 "2022-06-05T03:29:22Z")

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Does ApproxFun currently have a way to solve BVPs with mass conservation? For example 0=u''+f(u,v) and 0=v''-f(u,v) with homogeneous Neumann boundary conditions or periodic boundary conditions. Namely, can I tell ApproxF…

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## [Question about loop?](https://discourse.julialang.org/t/question-about-loop/82251)

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**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 6\
**Last updated:** [June 4, 2022, 11:51pm UTC](https://discourse.julialang.org/t/question-about-loop/82251 "2022-06-04T23:51:32Z")

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Dear all, I want to generate x1,x2,…x10, How can I write the code? julia\> for i in 1:10 x$i = i end I want to generate x1 = 1, x2 = 2...

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## [How to type this circle in Julia?](https://discourse.julialang.org/t/how-to-type-this-circle-in-julia/82254)

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**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 11:23pm UTC](https://discourse.julialang.org/t/how-to-type-this-circle-in-julia/82254 "2022-06-04T23:23:38Z")

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Dear all, How to type the circle below? plot((plot() for i in 1:7)..., layout=@layout(\[\_ ° \_; ° ° °; ° ° °\])) I try to type \\circ\[TAB\], but it’ not the same circle.

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## [How to use the macro @label and @goto](https://discourse.julialang.org/t/how-to-use-the-macro-label-and-goto/82247)

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**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 7\
**Last updated:** [June 4, 2022, 11:20pm UTC](https://discourse.julialang.org/t/how-to-use-the-macro-label-and-goto/82247 "2022-06-04T23:20:43Z")

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Dear all, I want to know how to use @label and @goto. Can you give me an example to use them? Many thanks.

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## [Complementarity.jl supports equality constraints?](https://discourse.julialang.org/t/complementarity-jl-supports-equality-constraints/82214)

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**Author:** [@vicentemunozlh](https://discourse.julialang.org/u/vicentemunozlh)\
**Replies:** 3\
**Last updated:** [June 4, 2022, 10:42pm UTC](https://discourse.julialang.org/t/complementarity-jl-supports-equality-constraints/82214 "2022-06-04T22:42:20Z")

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Hello, I have been unable to finish my MCP model because I cant find the way to add a constraint that is an equality. When I try combining and adding that constraint as @constraint or @NLconstraint and the others with @m…

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## [How to list all default parameters of optimizers](https://discourse.julialang.org/t/how-to-list-all-default-parameters-of-optimizers/82243)

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**Author:** [@Tri](https://discourse.julialang.org/u/Tri)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 9:02pm UTC](https://discourse.julialang.org/t/how-to-list-all-default-parameters-of-optimizers/82243 "2022-06-04T21:02:00Z")

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I know that I can change a parameter of optimizer by doing using JuMP using Ipopt model = Model(Ipopt.Optimizer) set\_optimizer\_attribute(model, “print\_level”, 0) How can I list all available parameters and their d…

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## [Integer value of difference between two dates](https://discourse.julialang.org/t/integer-value-of-difference-between-two-dates/82249)

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**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 9:00pm UTC](https://discourse.julialang.org/t/integer-value-of-difference-between-two-dates/82249 "2022-06-04T21:00:03Z")

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When subtracting two dates in Julia, the result is something like “293 days”. How can extract the integer part and ignore the “days” part?

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## [DifferentialEquations.jl Tutorial on BV Porblem](https://discourse.julialang.org/t/differentialequations-jl-tutorial-on-bv-porblem/77346)

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**Author:** [@NilsBruch](https://discourse.julialang.org/u/NilsBruch)\
**Replies:** 3\
**Last updated:** [June 4, 2022, 8:35pm UTC](https://discourse.julialang.org/t/differentialequations-jl-tutorial-on-bv-porblem/77346 "2022-06-04T20:35:28Z")

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Tthe tutorial section of DifferentialEquations.jl on Boundary Value Problems states that: " The third argument of BVProblem is the initial guess of the solution, which is constant in this example." In this example the c…

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## [Graph vertex and edge attributes](https://discourse.julialang.org/t/graph-vertex-and-edge-attributes/82234)

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**Author:** [@CopyOfA](https://discourse.julialang.org/u/CopyOfA)\
**Replies:** 4\
**Last updated:** [June 4, 2022, 7:06pm UTC](https://discourse.julialang.org/t/graph-vertex-and-edge-attributes/82234 "2022-06-04T19:06:29Z")

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I am a newbie to graph analytics in Julia and I am using Graphs.jl for graph analysis. In other libraries (e.g., R’s igraph or Python’s networkx) there is the ability to add attributes to the edges and vertices. However,…

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## [I think LLVM can do better here](https://discourse.julialang.org/t/i-think-llvm-can-do-better-here/82213)

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**Author:** [@mikmoore](https://discourse.julialang.org/u/mikmoore)\
**Replies:** 4\
**Last updated:** [June 4, 2022, 6:05pm UTC](https://discourse.julialang.org/t/i-think-llvm-can-do-better-here/82213 "2022-06-04T18:05:01Z")

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This an LLVM question that came up in the process of trying to make min/max faster. In that discussion, this other PR was brought up where @N5N3 suggests the following implementation for min: function \_\_min(x, y) di…

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## [Indexed variable names, or vector of vectors?](https://discourse.julialang.org/t/indexed-variable-names-or-vector-of-vectors/82240)

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**Author:** [@byrnoga](https://discourse.julialang.org/u/byrnoga)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 4:18pm UTC](https://discourse.julialang.org/t/indexed-variable-names-or-vector-of-vectors/82240 "2022-06-04T16:18:26Z")

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I have to update values of a number of vectors, say s1 … s20. I need a way to access arbitrarily s\_n, the nth index of variable s. s1=\[1 2 3\] s2=\[11 12 13 14 15\] # calculations lead to "n" and "val" n=2 val=16 # I app…

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## [Findnearest function?](https://discourse.julialang.org/t/findnearest-function/4143)

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**Author:** [@cormullion](https://discourse.julialang.org/u/cormullion)\
**Replies:** 20\
**Last updated:** [June 4, 2022, 3:58pm UTC](https://discourse.julialang.org/t/findnearest-function/4143 "2022-06-04T15:58:29Z")

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Is there a simple findnearest() function somewhere in Julia-land? A = \[1, 5, 12, 23\]; findnearest(A, 14) # -\> 3 findnearest(A, 18) # -\> 4

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## [Parameter Types in DiffEqFlux.jl versus DifferentialEquations.jl](https://discourse.julialang.org/t/parameter-types-in-diffeqflux-jl-versus-differentialequations-jl/79635)

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**Author:** [@jbu](https://discourse.julialang.org/u/jbu)\
**Replies:** 6\
**Last updated:** [June 4, 2022, 3:38pm UTC](https://discourse.julialang.org/t/parameter-types-in-diffeqflux-jl-versus-differentialequations-jl/79635 "2022-06-04T15:38:16Z")

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What are the differences between allowed parameter types in DiffEqFlux.jl versus DifferentialEquations.jl? The documentation for DifferentialEquations states the following: Note that the type for the parameters p can …

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## [Which version of Julia can run the following codes](https://discourse.julialang.org/t/which-version-of-julia-can-run-the-following-codes/64695)

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**Author:** [@tjk](https://discourse.julialang.org/u/tjk)\
**Replies:** 6\
**Last updated:** [June 4, 2022, 1:39pm UTC](https://discourse.julialang.org/t/which-version-of-julia-can-run-the-following-codes/64695 "2022-06-04T13:39:59Z")

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Hello, I am new to Julia and for research reasons I have to run a simple code for my friends. The code need Devito and JUDI:Installation · slimgroup/JUDI.jl Wiki · GitHub Here is the source code (Julia was installed on …

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## [Passing a Julia function to C and then calling from C code](https://discourse.julialang.org/t/passing-a-julia-function-to-c-and-then-calling-from-c-code/82217)

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**Author:** [@Fadi\_Hamad](https://discourse.julialang.org/u/Fadi_Hamad)\
**Replies:** 3\
**Last updated:** [June 4, 2022, 12:52pm UTC](https://discourse.julialang.org/t/passing-a-julia-function-to-c-and-then-calling-from-c-code/82217 "2022-06-04T12:52:30Z")

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Hello, I am trying to pass a Julia function to a some C code and then call that Julia function from within my C code. I followed the instruction from the section https://docs.julialang.org/en/v1/manual/calling-c-and-for…

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## [Another implementation of \`@memoize\` which is type inference friendly & generic functions](https://discourse.julialang.org/t/another-implementation-of-memoize-which-is-type-inference-friendly-generic-functions/3133)

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**Author:** [@FANG\_Colin](https://discourse.julialang.org/u/FANG_Colin)\
**Replies:** 0\
**Last updated:** [April 9, 2017, 11:37pm UTC](https://discourse.julialang.org/t/another-implementation-of-memoize-which-is-type-inference-friendly-generic-functions/3133 "2017-04-09T23:37:38Z")

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I made another Memoize.jl package for daily use of Julia. Suggestions & criticisms are welcom. Overview This package provides basic support for type inference friendly generic function memoization. It allows to customi…

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## [Create new column in dataframe based on list](https://discourse.julialang.org/t/create-new-column-in-dataframe-based-on-list/77483)

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**Author:** [@jonjilla](https://discourse.julialang.org/u/jonjilla)\
**Replies:** 5\
**Last updated:** [June 4, 2022, 12:32pm UTC](https://discourse.julialang.org/t/create-new-column-in-dataframe-based-on-list/77483 "2022-06-04T12:32:29Z")

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Hello, I’m trying to figure out how to create a 0,1 valued column in a dataframe based on comparing a dataframe column with a list. Here is an example data = DataFrame(:index =\> String\[\], :values =\> Int64\[\]) push!(da…

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## [Why does EnsembleGPUArray not save at the given time points the solution?](https://discourse.julialang.org/t/why-does-ensemblegpuarray-not-save-at-the-given-time-points-the-solution/78036)

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**Author:** [@Marius\_123](https://discourse.julialang.org/u/Marius_123)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 12:27pm UTC](https://discourse.julialang.org/t/why-does-ensemblegpuarray-not-save-at-the-given-time-points-the-solution/78036 "2022-06-04T12:27:41Z")

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I am trying to solve the same ODE for multiple parameters on the GPU, however as you can see in the provided code, the size of the solution trajectories is not the expected one. I get solution that are of the size 7\*6, b…

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## [Symbolic Geometry definition for PINN](https://discourse.julialang.org/t/symbolic-geometry-definition-for-pinn/80058)

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**Author:** [@LeoCott](https://discourse.julialang.org/u/LeoCott)\
**Replies:** 6\
**Last updated:** [June 4, 2022, 12:01pm UTC](https://discourse.julialang.org/t/symbolic-geometry-definition-for-pinn/80058 "2022-06-04T12:01:30Z")

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Dear all, I’m trying to solve the Reynolds-Averaged Navier Stokes (RANS) equations in a channel with periodic hills (see Figure below). The hill geometry is defined by a third order polynomial, here assumed to be co…

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## [Symbolics function](https://discourse.julialang.org/t/symbolics-function/82226)

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**Author:** [@jerry\_ji](https://discourse.julialang.org/u/jerry_ji)\
**Replies:** 1\
**Last updated:** [June 4, 2022, 11:59am UTC](https://discourse.julialang.org/t/symbolics-function/82226 "2022-06-04T11:59:53Z")

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Hi I trying to building an function with Symbolics.jl package, instead of output an Vector{Bool}, folloing code output an Vector{SymbolicUtils.Term{Bool, Nothing}}. using Symbolics N=12 @variables t c\[1:N\] Γ(t,c) Γ=…

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## [Gentle introduction to spatial modelling in Julia](https://discourse.julialang.org/t/gentle-introduction-to-spatial-modelling-in-julia/82060)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 2\
**Last updated:** [June 4, 2022, 11:56am UTC](https://discourse.julialang.org/t/gentle-introduction-to-spatial-modelling-in-julia/82060 "2022-06-04T11:56:01Z")

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Hello I have a set of ODEs to model the interaction between a bacterium and a phage, which gives the following results: I would like to model how the model works on a 2D space (let’s say a section of skin). The idea…

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