# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1190

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

**Page:** 1191

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## ["plot not defined" and / or "twinx not defined"](https://discourse.julialang.org/t/plot-not-defined-and-or-twinx-not-defined/72435)

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**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 6\
**Last updated:** [December 2, 2021, 9:41am UTC](https://discourse.julialang.org/t/plot-not-defined-and-or-twinx-not-defined/72435 "2021-12-02T09:41:36Z")

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Julia v1.7.0 I faced two issues: LoadError: UndefVarError: plot not defined and LoadError: UndefVarError: twinx not defined It took a while, how to achieve the result I was looking for. Below my simple example co…

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## [Extremely high first call latency Julia 1.6 versus 1.5 with multiphysics PDE solver](https://discourse.julialang.org/t/extremely-high-first-call-latency-julia-1-6-versus-1-5-with-multiphysics-pde-solver/71692)

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**Author:** [@amartinhuertas](https://discourse.julialang.org/u/amartinhuertas)\
**Replies:** 27\
**Last updated:** [December 2, 2021, 8:03am UTC](https://discourse.julialang.org/t/extremely-high-first-call-latency-julia-1-6-versus-1-5-with-multiphysics-pde-solver/71692 "2021-12-02T08:03:02Z")

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Dear all, we are experiencing extremely high first call latency times with Julia 1.6 when running our geophysical flows multiphysics finite element PDE solver (on the order of 15 hours on a supercomputer node with 192 G…

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## [Trouble with DifferentialEquations.jl using MPI with the integrator interface](https://discourse.julialang.org/t/trouble-with-differentialequations-jl-using-mpi-with-the-integrator-interface/70356)

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**Author:** [@reidr](https://discourse.julialang.org/u/reidr)\
**Replies:** 10\
**Last updated:** [December 2, 2021, 7:46am UTC](https://discourse.julialang.org/t/trouble-with-differentialequations-jl-using-mpi-with-the-integrator-interface/70356 "2021-12-02T07:46:56Z")

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I’m using DIfferentialEquations.jl to solve a very large (10^9) system of coupled ODEs. I’m using MPI because the memory required for the full system won’t find on a workstation. The problem fits pretty naturally with th…

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## [Thank you, Thank you, Thank you](https://discourse.julialang.org/t/thank-you-thank-you-thank-you/72406)

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**Author:** [@lewis](https://discourse.julialang.org/u/lewis)\
**Replies:** 1\
**Last updated:** [December 2, 2021, 6:40am UTC](https://discourse.julialang.org/t/thank-you-thank-you-thank-you/72406 "2021-12-02T06:40:06Z")

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Just installed Julia 1.7 for Apple Binary. STUNNING. So incredibly fast on just “eye-balling” performance. Will do a couple unscientific benchmarks later. Plots to GR almost blits to the screen first time! Plots to p…

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## [Conditionally read a subset of Arrow-data](https://discourse.julialang.org/t/conditionally-read-a-subset-of-arrow-data/72122)

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**Author:** [@fbanning](https://discourse.julialang.org/u/fbanning)\
**Replies:** 9\
**Last updated:** [December 2, 2021, 4:42am UTC](https://discourse.julialang.org/t/conditionally-read-a-subset-of-arrow-data/72122 "2021-12-02T04:42:32Z")

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Maybe my head is stuck in a loop right now but I have a question about dealing with arrow data. I have some data stored in a few large arrow files. I currently read the data via Arrow.Table("file.arrow") |\> DataFrame an…

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## [Missing not defined](https://discourse.julialang.org/t/missing-not-defined/72267)

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**Author:** [@sransome](https://discourse.julialang.org/u/sransome)\
**Replies:** 5\
**Last updated:** [December 2, 2021, 3:49am UTC](https://discourse.julialang.org/t/missing-not-defined/72267 "2021-12-02T03:49:34Z")

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Hi, I have been using the following to replace missing values with zero but it’s now failing and I can’t see why. replace!(df.myfloat64field, missing =\> 0.0) returns ERROR: UndefVarError: missing not defined same pr…

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## [Mosek and Ipopt](https://discourse.julialang.org/t/mosek-and-ipopt/72334)

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**Author:** [@Xuekui\_wang](https://discourse.julialang.org/u/Xuekui_wang)\
**Replies:** 4\
**Last updated:** [December 2, 2021, 2:13am UTC](https://discourse.julialang.org/t/mosek-and-ipopt/72334 "2021-12-02T02:13:57Z")

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when I use Ipopt as folows: m = Model(Ipopt.Optimizer) set\_optimizer\_attributes(m, "LOG" =\> 0) ... g\_p\_max\_soc=vcat(node\[i\].p̅ - g\_p\[i\],arg\_p) @constraint(m, g\_p\_max\_soc in SecondOrderCone()) there are errors as below: …

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## [Advent of Code 2021](https://discourse.julialang.org/t/advent-of-code-2021/72415)

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**Author:** [@stevensonmt](https://discourse.julialang.org/u/stevensonmt)\
**Replies:** 4\
**Last updated:** [December 2, 2021, 2:11am UTC](https://discourse.julialang.org/t/advent-of-code-2021/72415 "2021-12-02T02:11:46Z")

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Didn’t find a thread for Advent of Code 2021. This year I thought I’d use it to kickstart learning Julia. I plan to solve the exercises in Elixir and Julia. Last year I didn’t make it through to the end, hopefully this y…

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## [Stat.xticks fails in presence of Geom.vband and Geom.line](https://discourse.julialang.org/t/stat-xticks-fails-in-presence-of-geom-vband-and-geom-line/72416)

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**Author:** [@alan](https://discourse.julialang.org/u/alan)\
**Replies:** 1\
**Last updated:** [December 2, 2021, 1:57am UTC](https://discourse.julialang.org/t/stat-xticks-fails-in-presence-of-geom-vband-and-geom-line/72416 "2021-12-02T01:57:08Z")

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Trying to make a plot that includes Geom.line, Geom.vband, and Stat.xticks. Without Stat.xticks, it works fine. When I add Stat.xticks, I get: “Error showing value of type Plot: ERROR: The following aesthetics are requi…

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## [Floating point addition in Julia](https://discourse.julialang.org/t/floating-point-addition-in-julia/72341)

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**Author:** [@n90](https://discourse.julialang.org/u/n90)\
**Replies:** 6\
**Last updated:** [December 2, 2021, 1:54am UTC](https://discourse.julialang.org/t/floating-point-addition-in-julia/72341 "2021-12-02T01:54:33Z")

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I am a bit confused about the floating value addition in Julia. When I try to add two float values in Julia am getting a non rounded value with more precision. julia\> 106.8 + 1.085 107.88499999999999 I want to know if…

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## [Why is this Project.toml compat not enforced?](https://discourse.julialang.org/t/why-is-this-project-toml-compat-not-enforced/72419)

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**Author:** [@diederikb](https://discourse.julialang.org/u/diederikb)\
**Replies:** 2\
**Last updated:** [December 2, 2021, 1:36am UTC](https://discourse.julialang.org/t/why-is-this-project-toml-compat-not-enforced/72419 "2021-12-02T01:36:42Z")

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Hi everyone, I have trouble understanding the following behavior that I tested on Julia 1.6.4 and 1.7.0. If I create an empty project and \] add PotentialFlow, this package cannot be imported because of the following err…

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## [Enum not at top level expression](https://discourse.julialang.org/t/enum-not-at-top-level-expression/23119)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 7\
**Last updated:** [December 2, 2021, 1:03am UTC](https://discourse.julialang.org/t/enum-not-at-top-level-expression/23119 "2021-12-02T01:03:57Z")

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Hello guys! I have something like this: So basically an enum array, where a specific enum like “Points” refers to a string and type “POINTS” / Float32. My question is: If I try putting this in the main function I g…

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## [Merging dataframes on dates](https://discourse.julialang.org/t/merging-dataframes-on-dates/72417)

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**Author:** [@Bruno322](https://discourse.julialang.org/u/Bruno322)\
**Replies:** 3\
**Last updated:** [December 1, 2021, 11:29pm UTC](https://discourse.julialang.org/t/merging-dataframes-on-dates/72417 "2021-12-01T23:29:25Z")

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I’m trying to clean a data set and I am stuck at the last step. The main dataframe, that I call maindf, will contain all the data and has 3000 rows and 200 columns, like this Each row of maindf will be filled with a…

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## [Which library for a Monte Carlo web app?](https://discourse.julialang.org/t/which-library-for-a-monte-carlo-web-app/72397)

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**Author:** [@patrick](https://discourse.julialang.org/u/patrick)\
**Replies:** 5\
**Last updated:** [December 1, 2021, 11:08pm UTC](https://discourse.julialang.org/t/which-library-for-a-monte-carlo-web-app/72397 "2021-12-01T23:08:55Z")

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Let me preface this by saying that I’m a Julia novice, and I have never done any web dev or serious plotting. So, a quick pointer to the right packages for my needs should suffice as an answer. In a nutshell: I want to …

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## [M1 vs. M1Pro vs. M1Max For DiffEq & Optim](https://discourse.julialang.org/t/m1-vs-m1pro-vs-m1max-for-diffeq-optim/72418)

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**Author:** [@donkeysaddle](https://discourse.julialang.org/u/donkeysaddle)\
**Replies:** 0\
**Last updated:** [December 1, 2021, 11:00pm UTC](https://discourse.julialang.org/t/m1-vs-m1pro-vs-m1max-for-diffeq-optim/72418 "2021-12-01T23:00:55Z")

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I think I will experience a performance boost with any of the Arm Macs but I was curious to hear people’s experiences particularly as it pertains to DifferentialEquations.jl and Optim.jl. My question is quite vague becau…

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## [Strange Pkg warning in 1.7](https://discourse.julialang.org/t/strange-pkg-warning-in-1-7/72412)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 0\
**Last updated:** [December 1, 2021, 10:34pm UTC](https://discourse.julialang.org/t/strange-pkg-warning-in-1-7/72412 "2021-12-01T22:34:26Z")

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I installed Julia 1.7, and now I am getting a warning when loading some packages (I opened an issue here in the package repo). In particular, using PreallocationTools after loading ForwardDiff in Julia 1.7 results in thi…

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## [\[ANN\] BulkAndTails.jl](https://discourse.julialang.org/t/ann-bulkandtails-jl/72310)

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**Author:** [@mlkrock](https://discourse.julialang.org/u/mlkrock)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 10:04pm UTC](https://discourse.julialang.org/t/ann-bulkandtails-jl/72310 "2021-12-01T22:04:30Z")

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Hello. I’ve just registered BulkAndTails.jl, which offers an interface for the seven-parameter Bulk-And-Tails (BATs) distribution in the style of Distributions.jl. BATs was recently introduced in Stein 2021 to model an e…

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## [Lift and @Lift generically](https://discourse.julialang.org/t/lift-and-lift-generically/72399)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 3\
**Last updated:** [December 1, 2021, 8:40pm UTC](https://discourse.julialang.org/t/lift-and-lift-generically/72399 "2021-12-01T20:40:56Z")

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I have some routines that I used for calculations and simulation. Occasionally I want to use those same routines in a Makie GUI using observable Nodes and lift/@lift. In the past I have two versions of the plotting fun…

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## [New julia 1.7 install with jill: how transfer julia 1.6 packages (macos)](https://discourse.julialang.org/t/new-julia-1-7-install-with-jill-how-transfer-julia-1-6-packages-macos/72394)

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**Author:** [@murrayE](https://discourse.julialang.org/u/murrayE)\
**Replies:** 6\
**Last updated:** [December 1, 2021, 8:36pm UTC](https://discourse.julialang.org/t/new-julia-1-7-install-with-jill-how-transfer-julia-1-6-packages-macos/72394 "2021-12-01T20:36:45Z")

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Under macOS I had previously installed julia 1.6\* directly from Download Julia. This created ~/.julia/, which includes subdirectories config, environments, packages, and others. In particular, packages that I install go …

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## [ACOPF Problem](https://discourse.julialang.org/t/acopf-problem/72375)

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**Author:** [@priod](https://discourse.julialang.org/u/priod)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 7:40pm UTC](https://discourse.julialang.org/t/acopf-problem/72375 "2021-12-01T19:40:38Z")

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I am trying to run an ACOPF (Alternating current optimal power flow) in the two-node network for a variable load in time “t”. The result of the model is just the zero values and nothing else. Can someone suggest to me a …

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## [Border Matrix in Pluto](https://discourse.julialang.org/t/border-matrix-in-pluto/72253)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 4\
**Last updated:** [December 1, 2021, 7:21pm UTC](https://discourse.julialang.org/t/border-matrix-in-pluto/72253 "2021-12-01T19:21:14Z")

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Hi, I was wondering if it is possible to use a bordermatrix in Pluto? I tried the following without success: md" $M = \\bordermatrix{~ & x & y \\cr A & 1 & 0 \\cr B & 0 & 1 \\cr}$ "

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## [Makie Scatter Plot recipe for vector of custom types](https://discourse.julialang.org/t/makie-scatter-plot-recipe-for-vector-of-custom-types/72255)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 5\
**Last updated:** [December 1, 2021, 7:05pm UTC](https://discourse.julialang.org/t/makie-scatter-plot-recipe-for-vector-of-custom-types/72255 "2021-12-01T19:05:14Z")

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This should be easy. At least it was for plots. I don’t understand what I am doing wrong. Looking for a simple example that shows me how to use convert\_arguments. I think the documentation makes too many assumptions …

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## [Error during initialization of module GMP](https://discourse.julialang.org/t/error-during-initialization-of-module-gmp/72293)

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**Author:** [@Samuel\_Dupree](https://discourse.julialang.org/u/Samuel_Dupree)\
**Replies:** 1\
**Last updated:** [December 1, 2021, 6:29pm UTC](https://discourse.julialang.org/t/error-during-initialization-of-module-gmp/72293 "2021-12-01T18:29:47Z")

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I’ve just installed Julia-1.6.4 onto a Mac Pro desktop (2019) running Mac OSX Monterey (ver. 12.0.1). When I startup Julia I get the following message: exec '/Applications/Julia-1.6.app/Contents/Resources/julia/bin/juli…

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## [Multiple Julia environments in Jupyter](https://discourse.julialang.org/t/multiple-julia-environments-in-jupyter/72392)

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**Author:** [@dodoplus](https://discourse.julialang.org/u/dodoplus)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 6:21pm UTC](https://discourse.julialang.org/t/multiple-julia-environments-in-jupyter/72392 "2021-12-01T18:21:01Z")

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Hi, I want to play with the new Apple Silicon Julia 1.7 without (yet) replacing my x86 environment. Therefore, I’d like to add another kernel with its own environment to Jupyter. Is there an easy (or not so easy) way t…

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## [Help with ModelingToolkit](https://discourse.julialang.org/t/help-with-modelingtoolkit/72328)

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**Author:** [@contradict](https://discourse.julialang.org/u/contradict)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 6:14pm UTC](https://discourse.julialang.org/t/help-with-modelingtoolkit/72328 "2021-12-01T18:14:39Z")

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I am playing with the continuous\_events feature in ModelingToolkit and have gotten stuck. My current example is here. With ModelingToolkit 7.1.3, running limit\_example() produces the error ERROR: AssertionError: maximum…

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## [Modifying vectors in for loop doesn't work](https://discourse.julialang.org/t/modifying-vectors-in-for-loop-doesnt-work/72391)

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**Author:** [@dhryniuk](https://discourse.julialang.org/u/dhryniuk)\
**Replies:** 1\
**Last updated:** [December 1, 2021, 5:47pm UTC](https://discourse.julialang.org/t/modifying-vectors-in-for-loop-doesnt-work/72391 "2021-12-01T17:47:30Z")

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I would like to have a function which would generate vectors of the same length and average them together into a single vector. I can’t quite understand why the following example wouldn’t work (the value of vector remain…

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## [Sum() one column in dataframe](https://discourse.julialang.org/t/sum-one-column-in-dataframe/72387)

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**Author:** [@AlexanderChen](https://discourse.julialang.org/u/AlexanderChen)\
**Replies:** 4\
**Last updated:** [December 1, 2021, 5:38pm UTC](https://discourse.julialang.org/t/sum-one-column-in-dataframe/72387 "2021-12-01T17:38:21Z")

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Hi, This is the structure of the dataframe: Row │ NAMES NAMES\_NUMBER P\_NUMBER\_NAMES P\_NUMBER\_NUMBERS TOTAL │ String Int64 Int64 Int64 Int64 ──────┼─────────────…

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## [1.7 is great](https://discourse.julialang.org/t/1-7-is-great/72344)

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**Author:** [@gustaphe](https://discourse.julialang.org/u/gustaphe)\
**Replies:** 4\
**Last updated:** [December 1, 2021, 5:35pm UTC](https://discourse.julialang.org/t/1-7-is-great/72344 "2021-12-01T17:35:09Z")

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I have been running the rc version of 1.7 for a while, but I guess now is as good a time as any to say it: I really like the improvements made (and Julia in general!) A big thanks to the developers. Good job!

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## [Updating only a subset of parameters in a neural network using Flux](https://discourse.julialang.org/t/updating-only-a-subset-of-parameters-in-a-neural-network-using-flux/72312)

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**Author:** [@Handam](https://discourse.julialang.org/u/Handam)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 5:25pm UTC](https://discourse.julialang.org/t/updating-only-a-subset-of-parameters-in-a-neural-network-using-flux/72312 "2021-12-01T17:25:53Z")

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I am currently playing around with actor-critic methods. In my current problem, the actor has four outputs: pol = Chain(Dense(6, 32, relu), Dense(32, 4)) However, depending on the state only a subset of the actions are…

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## [How to find dimesion of a polyhedron](https://discourse.julialang.org/t/how-to-find-dimesion-of-a-polyhedron/72383)

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**Author:** [@XLVII](https://discourse.julialang.org/u/XLVII)\
**Replies:** 2\
**Last updated:** [December 1, 2021, 4:36pm UTC](https://discourse.julialang.org/t/how-to-find-dimesion-of-a-polyhedron/72383 "2021-12-01T16:36:14Z")

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K = polyhedron(vrep(\[Ray(\[0.0,0.0,1.0\])\] )) let say we have K polyhedron is there any function like dim(k) which give the dimension of k if no how to find dimesion? using LinearAlgebra using Combinatorics using Poly…

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