# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=486

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**Page:** 487

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## [Array of boxes using Makie and volume](https://discourse.julialang.org/t/array-of-boxes-using-makie-and-volume/27350)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 7\
**Last updated:** [August 19, 2019, 1:48pm UTC](https://discourse.julialang.org/t/array-of-boxes-using-makie-and-volume/27350 "2019-08-19T13:48:54Z")

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Hi, the examples from the Makie documentation show how to build a cube (using volume), but if I try to update the scene with a new one, they overlap. Any ideas on how to solve this. I want to create an array of cubes. u…

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## [Optim.jl with autodiff and complex numbers](https://discourse.julialang.org/t/optim-jl-with-autodiff-and-complex-numbers/27684)

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**Author:** [@Dandan](https://discourse.julialang.org/u/Dandan)\
**Replies:** 8\
**Last updated:** [August 18, 2019, 8:03pm UTC](https://discourse.julialang.org/t/optim-jl-with-autodiff-and-complex-numbers/27684 "2019-08-18T20:03:03Z")

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Hello! I would like to use Optim.jl with the target function defined on a complex Stiefel manifold (unitary matrices) of some large size. Stiefel manifold is already implemented in Optim.jl. The problem is I can’t use …

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## [Changing the righthand side in a callback](https://discourse.julialang.org/t/changing-the-righthand-side-in-a-callback/27462)

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**Author:** [@FHell](https://discourse.julialang.org/u/FHell)\
**Replies:** 6\
**Last updated:** [August 18, 2019, 6:31pm UTC](https://discourse.julialang.org/t/changing-the-righthand-side-in-a-callback/27462 "2019-08-18T18:31:31Z")

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Hi everyone, I am wondering how to correctly change the right hand side inside a DifferentialEquations callback. If I don’t reinit the system runs through but gives wrong results (compared to just running new different…

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## [Grassman algebras for electromagnetic scattering](https://discourse.julialang.org/t/grassman-algebras-for-electromagnetic-scattering/27681)

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**Author:** [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Replies:** 7\
**Last updated:** [August 18, 2019, 2:53pm UTC](https://discourse.julialang.org/t/grassman-algebras-for-electromagnetic-scattering/27681 "2019-08-18T14:53:05Z")

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All of the math you are trying to do here could be simplified by using Grassmann.jl multivectors instead of matrices. It encodes both rotational algebras as well as spacetime geometry, so that matrices are no longer need…

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## [Custom Flux loss function \`culiteral\_pow()\` error](https://discourse.julialang.org/t/custom-flux-loss-function-culiteral-pow-error/27671)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 2\
**Last updated:** [August 18, 2019, 6:16am UTC](https://discourse.julialang.org/t/custom-flux-loss-function-culiteral-pow-error/27671 "2019-08-18T06:16:27Z")

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Hi, I’m trying to build a MLP for a regression problem. A sample of my data looks like this: x= \\left\[ {\\begin{array}{c} \\hat{m\_1}\\\\ \\vdots \\\\ \\hat{m\_k}\\\\ \\hat{n\_1}\\\\ \\vdots \\\\ \\hat{n\_k}\\\\ P \\…

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## [Winston on Travis](https://discourse.julialang.org/t/winston-on-travis/27659)

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**Author:** [@Janis\_Erdmanis](https://discourse.julialang.org/u/Janis_Erdmanis)\
**Replies:** 3\
**Last updated:** [August 17, 2019, 8:02pm UTC](https://discourse.julialang.org/t/winston-on-travis/27659 "2019-08-17T20:02:07Z")

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I am trying to build documentation on Travis with Literate.jl which contains figures made with Winston.jl. Locally everything works great, but when I build stuff on Travis I get precompilation error: value = Failed to p…

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## [Pkg update downgrade JuMP](https://discourse.julialang.org/t/pkg-update-downgrade-jump/27621)

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**Author:** [@remi-garcia](https://discourse.julialang.org/u/remi-garcia)\
**Replies:** 3\
**Last updated:** [August 17, 2019, 3:11pm UTC](https://discourse.julialang.org/t/pkg-update-downgrade-jump/27621 "2019-08-17T15:11:53Z")

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Hi, When I add JuMP and GLPK I get this: (v1.1) pkg\> st Status \`~/.julia/environments/v1.1/Project.toml\` (empty environment) (v1.1) pkg\> add JuMP GLPK Resolving package versions... Updating \`~/.julia/environm…

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## [Defining the objective using function](https://discourse.julialang.org/t/defining-the-objective-using-function/27633)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 5\
**Last updated:** [August 17, 2019, 2:09pm UTC](https://discourse.julialang.org/t/defining-the-objective-using-function/27633 "2019-08-17T14:09:55Z")

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Dear users, I need to minimize this nonlinear function: f(x1,x2) = 1 + x2^2 - x - sin(x1) with box constraints. How can I do this by using a function, named E-restrito, providing as argument f? My code is: function E…

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## [How to reconfigure Couenne for Cplex in windows](https://discourse.julialang.org/t/how-to-reconfigure-couenne-for-cplex-in-windows/27581)

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**Author:** [@Raminel](https://discourse.julialang.org/u/Raminel)\
**Replies:** 2\
**Last updated:** [August 17, 2019, 2:02pm UTC](https://discourse.julialang.org/t/how-to-reconfigure-couenne-for-cplex-in-windows/27581 "2019-08-17T14:02:54Z")

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Hi all, Can someone tell me how I can “reconfigure and recompile” Couenne to use Cplex for lp solver? I added this to couenne.opt “lp\_solver cplex” and read in teh manual that I need to run the configuration file after…

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## [Makie on Travis](https://discourse.julialang.org/t/makie-on-travis/27637)

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**Author:** [@Janis\_Erdmanis](https://discourse.julialang.org/u/Janis_Erdmanis)\
**Replies:** 2\
**Last updated:** [August 17, 2019, 11:34am UTC](https://discourse.julialang.org/t/makie-on-travis/27637 "2019-08-17T11:34:24Z")

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Hello everyone! I am writing documentation for a package which includes animations created with Makie. As I am using Literate.jl it makes sense to generate animations at the time of compiling the document with Documente…

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## [DAEs and initialization](https://discourse.julialang.org/t/daes-and-initialization/27648)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 1\
**Last updated:** [August 17, 2019, 11:33am UTC](https://discourse.julialang.org/t/daes-and-initialization/27648 "2019-08-17T11:33:07Z")

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I need to use DAE formulation of models, and wonder about the initialization… From the documentation: Question: Does this imply that those differential\_vars which are differential, are assumed to have correct initial…

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## [GPU simulation time of neural ODE program](https://discourse.julialang.org/t/gpu-simulation-time-of-neural-ode-program/27416)

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**Author:** [@JunichiFukui](https://discourse.julialang.org/u/JunichiFukui)\
**Replies:** 8\
**Last updated:** [August 16, 2019, 11:43pm UTC](https://discourse.julialang.org/t/gpu-simulation-time-of-neural-ode-program/27416 "2019-08-16T23:43:45Z")

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Hello, I’m trying to run the following neural ODE program using GPU. If I run the code using GPU (NVIDIA GeForce GTX 1050), the simulation time of Flux.train!(loss\_n\_ode, ps, data, opt, cb = cb) part was much longer tha…

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## [Type FPFunctionalCache has no field caches error](https://discourse.julialang.org/t/type-fpfunctionalcache-has-no-field-caches-error/27598)

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**Author:** [@Farnazmdi](https://discourse.julialang.org/u/Farnazmdi)\
**Replies:** 5\
**Last updated:** [August 16, 2019, 6:42pm UTC](https://discourse.julialang.org/t/type-fpfunctionalcache-has-no-field-caches-error/27598 "2019-08-16T18:42:27Z")

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Hi, I am using BlackBoxOptim and I get this error when I run it. Starting optimization with optimizer DiffEvoOpt{FitPopulation{Float64},RadiusLimitedSelector,BlackBoxOptim.AdaptiveDiffEvoRandBin{3},RandomBound{Continuo…

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## [CSV in Parallel Error](https://discourse.julialang.org/t/csv-in-parallel-error/27585)

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**Author:** [@austinbean](https://discourse.julialang.org/u/austinbean)\
**Replies:** 6\
**Last updated:** [August 16, 2019, 1:12pm UTC](https://discourse.julialang.org/t/csv-in-parallel-error/27585 "2019-08-16T13:12:49Z")

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I have a very large (160 Gb) csv file. I had the idea to do some processing of the file in parallel, but I’m stuck on an error in CSV.jl. What I wanted to do was use CSV.Rows on non-contiguous chunks of the file across…

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## [Hermitian representation of a matrix](https://discourse.julialang.org/t/hermitian-representation-of-a-matrix/27594)

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**Author:** [@darknoob](https://discourse.julialang.org/u/darknoob)\
**Replies:** 5\
**Last updated:** [August 15, 2019, 11:30pm UTC](https://discourse.julialang.org/t/hermitian-representation-of-a-matrix/27594 "2019-08-15T23:30:13Z")

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Hi! I have the following problem: I have done some computations in order to obtain three 4x4-matrices represented as a 12x4-array, aka a span V of 4 linear independet vectors comming from C^12; these 4 vectors build a b…

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## [Calculating Lyapunov Exponents with ModelingToolkit](https://discourse.julialang.org/t/calculating-lyapunov-exponents-with-modelingtoolkit/26641)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 17\
**Last updated:** [August 14, 2019, 10:49am UTC](https://discourse.julialang.org/t/calculating-lyapunov-exponents-with-modelingtoolkit/26641 "2019-08-14T10:49:52Z")

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Hi all, suggested in this thread here Chaostools tangent\_integrator stiff solvers - #26 by jamblejoe, one could use ModelingToolkit the approach the following scenario. One has a dynamical system defined by n different…

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## [Bioinformatics.jl - Helper functions for bioinformatics and rosalind.info problems](https://discourse.julialang.org/t/bioinformatics-jl-helper-functions-for-bioinformatics-and-rosalind-info-problems/27506)

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**Author:** [@mrtkp9993](https://discourse.julialang.org/u/mrtkp9993)\
**Replies:** 1\
**Last updated:** [August 13, 2019, 9:06pm UTC](https://discourse.julialang.org/t/bioinformatics-jl-helper-functions-for-bioinformatics-and-rosalind-info-problems/27506 "2019-08-13T21:06:51Z")

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https://github.com/mrtkp9993/Bioinformatics.jl

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## [Discussion: SPIR-V analog to CUDAnative?](https://discourse.julialang.org/t/discussion-spir-v-analog-to-cudanative/27427)

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**Author:** [@wsphillips](https://discourse.julialang.org/u/wsphillips)\
**Replies:** 6\
**Last updated:** [August 13, 2019, 5:20pm UTC](https://discourse.julialang.org/t/discussion-spir-v-analog-to-cudanative/27427 "2019-08-13T17:20:13Z")

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Almost certainly this has been thought of, but surprisingly I haven’t been able to find any mention of it on discourse and not really any repos…(although I noticed VulkanCore is perhaps waking up :smiley: ) Has there be…

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## [Convex.jl: Trouble with partially specified function inside another problem?](https://discourse.julialang.org/t/convex-jl-trouble-with-partially-specified-function-inside-another-problem/26508)

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**Author:** [@Jacob\_Stevens-Haas](https://discourse.julialang.org/u/Jacob_Stevens-Haas)\
**Replies:** 5\
**Last updated:** [August 13, 2019, 4:13pm UTC](https://discourse.julialang.org/t/convex-jl-trouble-with-partially-specified-function-inside-another-problem/26508 "2019-08-13T16:13:45Z")

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I’m trying to use a partially defined function as in DCP documentation. I have a minimization problem including convex function that isn’t a disciplined convex function. It’s fenchel conjugate is, however, so I was hop…

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## [How to add Integer contraint to variables using the @variables macro?](https://discourse.julialang.org/t/how-to-add-integer-contraint-to-variables-using-the-variables-macro/27500)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [August 13, 2019, 3:02pm UTC](https://discourse.julialang.org/t/how-to-add-integer-contraint-to-variables-using-the-variables-macro/27500 "2019-08-13T15:02:49Z")

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To bound a variable to be integer I can use integer=true, e.g. @variable(m, 0 \<= p, integer=true, start=1), but how to do that when I use the @variables macro? I did try as such, but it is not recognised (also base\_name …

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## [Mux.jl mysterious d() function](https://discourse.julialang.org/t/mux-jl-mysterious-d-function/27436)

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**Author:** [@milesf](https://discourse.julialang.org/u/milesf)\
**Replies:** 4\
**Last updated:** [August 13, 2019, 4:45am UTC](https://discourse.julialang.org/t/mux-jl-mysterious-d-function/27436 "2019-08-13T04:45:41Z")

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Where is this d() function defined? I can’t find it in Mux.jl, or HTTP.jl. https://github.com/JuliaWeb/Mux.jl/blob/b8419df8774c0ee14052320d22bab41b653d0c01/src/routing.jl#L19

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## [ForwardDiff fast construction of vectors/matrices without cats](https://discourse.julialang.org/t/forwarddiff-fast-construction-of-vectors-matrices-without-cats/27468)

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**Author:** [@ys3636](https://discourse.julialang.org/u/ys3636)\
**Replies:** 6\
**Last updated:** [August 12, 2019, 9:25pm UTC](https://discourse.julialang.org/t/forwarddiff-fast-construction-of-vectors-matrices-without-cats/27468 "2019-08-12T21:25:21Z")

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Hi, I’m trying to use Optim to do maximum-likelihood estimation of some parameters in a custom likelihood model. In particular, I would like to incorporate autodiff to increase the accuracy of my estimates. However, set…

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## [Container of PSD variables in JuMP](https://discourse.julialang.org/t/container-of-psd-variables-in-jump/27448)

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**Author:** [@nrontsis](https://discourse.julialang.org/u/nrontsis)\
**Replies:** 3\
**Last updated:** [August 12, 2019, 4:02pm UTC](https://discourse.julialang.org/t/container-of-psd-variables-in-jump/27448 "2019-08-12T16:02:21Z")

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What is the best way to create a container of PSD “variables” such that X\[i\] = i-th PSD variable?

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## [Memory usage seems extremely high in standard Flux, is it any better with Zygote?](https://discourse.julialang.org/t/memory-usage-seems-extremely-high-in-standard-flux-is-it-any-better-with-zygote/27435)

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**Author:** [@tue](https://discourse.julialang.org/u/tue)\
**Replies:** 2\
**Last updated:** [August 12, 2019, 7:56am UTC](https://discourse.julialang.org/t/memory-usage-seems-extremely-high-in-standard-flux-is-it-any-better-with-zygote/27435 "2019-08-12T07:56:20Z")

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Hi I’m running some tests on CIFAR10, with a residual CNN, and so far I’m getting very discouraging results for the memory consumption. I’m doing something rather atypical where I regularize each layer of my network sepa…

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## [Is the ODBC.load function implemented?](https://discourse.julialang.org/t/is-the-odbc-load-function-implemented/27330)

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**Author:** [@js135005](https://discourse.julialang.org/u/js135005)\
**Replies:** 3\
**Last updated:** [August 12, 2019, 4:12am UTC](https://discourse.julialang.org/t/is-the-odbc-load-function-implemented/27330 "2019-08-12T04:12:39Z")

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I am trying to load data from a very small dataframe into an MS SQL server database. This is documented in the ODBC.jl documentation, albeit as experimental. However it does not find the load function at all when I try …

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## [Transducers for sufficient statistics](https://discourse.julialang.org/t/transducers-for-sufficient-statistics/27425)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 5\
**Last updated:** [August 12, 2019, 3:19am UTC](https://discourse.julialang.org/t/transducers-for-sufficient-statistics/27425 "2019-08-12T03:19:14Z")

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For independent observations from some distribution, we end up doing a lot of sum(logpdf.(myDist, x)) But in some cases, the algebra simplified a lot, and we can just track sufficient statistics. A common example of th…

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## [Posits - a new approach could sink floating point computation](https://discourse.julialang.org/t/posits-a-new-approach-could-sink-floating-point-computation/26176)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 49\
**Last updated:** [August 11, 2019, 10:05pm UTC](https://discourse.julialang.org/t/posits-a-new-approach-could-sink-floating-point-computation/26176 "2019-08-11T22:05:08Z")

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Well worth watching this video from the London Julia Meetup. Milan Kloewer using Posits in a real ocean modelling code. You can run the code by defining Mytype=posti - or double, or single precision etc. …

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## [How to create \`DataFrame\` from using NamedTuple keys as column names](https://discourse.julialang.org/t/how-to-create-dataframe-from-using-namedtuple-keys-as-column-names/27405)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 4\
**Last updated:** [August 11, 2019, 8:50pm UTC](https://discourse.julialang.org/t/how-to-create-dataframe-from-using-namedtuple-keys-as-column-names/27405 "2019-08-11T20:50:41Z")

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I have a function that returns a NamedTuple with 7 entries. The names are obviously Symbols and the entries are Int64. As this function is run many times, I would like to store the returned data as rows in a DataFrame, b…

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## [JuMP: Piecewise linear cost function](https://discourse.julialang.org/t/jump-piecewise-linear-cost-function/27269)

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**Author:** [@uwechsler](https://discourse.julialang.org/u/uwechsler)\
**Replies:** 3\
**Last updated:** [August 10, 2019, 9:43pm UTC](https://discourse.julialang.org/t/jump-piecewise-linear-cost-function/27269 "2019-08-10T21:43:58Z")

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I am trying to solve an optimization problem with a piecewise linear cost function, which writes as: \\ell^{max}(z) := \\max\_{\\omega\\in\\Omega} \\ell(z+\\omega) where the cost function is piecewise continous, e.g. \\ell(z) =…

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## [Optim constrained optimization issues](https://discourse.julialang.org/t/optim-constrained-optimization-issues/27333)

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**Author:** [@ys3636](https://discourse.julialang.org/u/ys3636)\
**Replies:** 8\
**Last updated:** [August 9, 2019, 5:43pm UTC](https://discourse.julialang.org/t/optim-constrained-optimization-issues/27333 "2019-08-09T17:43:09Z")

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Hi, Apologies, Julia newcomer. I’m trying to use Optim.jl to fit the parameters of a particular custom noise model by minimizing negative log-likelihood, but I’m running into some issues where methods that exist in prev…

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