# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=295

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**Page:** 296

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## [Reshaping dataframe](https://discourse.julialang.org/t/reshaping-dataframe/78020)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 13\
**Last updated:** [March 17, 2022, 2:52pm UTC](https://discourse.julialang.org/t/reshaping-dataframe/78020 "2022-03-17T14:52:34Z")

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I show a way to transform the starting table to have only one “X” per row. I ask for comments on how to do the various steps differently and / or better. For example how to insert an “index” column or how to filter the…

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## [How to use AlgebraOfgraphics's sorter](https://discourse.julialang.org/t/how-to-use-algebraofgraphicss-sorter/78030)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 2\
**Last updated:** [March 17, 2022, 2:35pm UTC](https://discourse.julialang.org/t/how-to-use-algebraofgraphicss-sorter/78030 "2022-03-17T14:35:40Z")

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It is not clear to me from the sorter documentation how to use the Algebra of Graphics’s sorter. My current attempt is: plt \*= mapping(marker=:l) |\> sorter(Vector(1:13) .|\> string) Anyone who knows how to use it?

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## [Approximating a Numerically Computed Distribution](https://discourse.julialang.org/t/approximating-a-numerically-computed-distribution/77972)

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**Author:** [@marcpabst](https://discourse.julialang.org/u/marcpabst)\
**Replies:** 5\
**Last updated:** [March 17, 2022, 2:13pm UTC](https://discourse.julialang.org/t/approximating-a-numerically-computed-distribution/77972 "2022-03-17T14:13:43Z")

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I have a very simple, numerically computed posterior (note that I’m not randomly sampling from the posterior but actually calculate it’s (log-)densities over a given interval) that I know converges to a Normal distributi…

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## [LoopVectorization multithreading for multidimensional arrays](https://discourse.julialang.org/t/loopvectorization-multithreading-for-multidimensional-arrays/77064)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 24\
**Last updated:** [March 17, 2022, 1:04pm UTC](https://discourse.julialang.org/t/loopvectorization-multithreading-for-multidimensional-arrays/77064 "2022-03-17T13:04:00Z")

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What is the correct way to use @tturbo to parallelize iteration over multidimensional array? I can think of several variants: Parallelize the iteration over cartesian indices: @tturbo for I in eachindex(a) Paralleliz…

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## [How to make empty dataframe with column names?](https://discourse.julialang.org/t/how-to-make-empty-dataframe-with-column-names/77936)

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**Author:** [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)\
**Replies:** 5\
**Last updated:** [March 17, 2022, 10:21am UTC](https://discourse.julialang.org/t/how-to-make-empty-dataframe-with-column-names/77936 "2022-03-17T10:21:19Z")

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df = DataFrame(x = \[\], y = String\[\]) 0×2 DataFrame I know that empty dataframe with column names, but if i have long column names below, how can i make the empty dataframe? julia\> nodenames 224-element Vecto…

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## [Numerical computation of continuous Fourier transforms](https://discourse.julialang.org/t/numerical-computation-of-continuous-fourier-transforms/77999)

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**Author:** [@DanielVandH](https://discourse.julialang.org/u/DanielVandH)\
**Replies:** 3\
**Last updated:** [March 17, 2022, 10:05am UTC](https://discourse.julialang.org/t/numerical-computation-of-continuous-fourier-transforms/77999 "2022-03-17T10:05:45Z")

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Are there any packages available for computation of Fourier transforms of the form F(x\_k) = \\int\_{-\\infty}^\\infty f(t)\\mathrm{e}^{-\\mathrm{i}tx\_k}\\,\\mathrm{d}t? e.g. the method developed by DBailey and Swarztrauber (The …

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## [Indexing DataFrame with : does not generate a copy](https://discourse.julialang.org/t/indexing-dataframe-with-does-not-generate-a-copy/78002)

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**Author:** [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Replies:** 2\
**Last updated:** [March 17, 2022, 6:16am UTC](https://discourse.julialang.org/t/indexing-dataframe-with-does-not-generate-a-copy/78002 "2022-03-17T06:16:04Z")

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The DataFrames.jl documentation says Since df\[!, :col\] does not make a copy, changing the elements of the column vector returned by this syntax will affect the values stored in the original df . To get a copy of the co…

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## [Using alternative array container types in JuMP](https://discourse.julialang.org/t/using-alternative-array-container-types-in-jump/77707)

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**Author:** [@BSnelling](https://discourse.julialang.org/u/BSnelling)\
**Replies:** 5\
**Last updated:** [March 16, 2022, 8:03pm UTC](https://discourse.julialang.org/t/using-alternative-array-container-types-in-jump/77707 "2022-03-16T20:03:04Z")

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I am trying to force the container type used by a JuMP model. My example uses KeyedArray but I’ve seen a similar error when specifying other types from outside JuMP (e.g. AxisArray). using JuMP, AxisKeys, GLPK vals = \[…

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## [Juniper integer-objective fails on specific parameters](https://discourse.julialang.org/t/juniper-integer-objective-fails-on-specific-parameters/77940)

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**Author:** [@ecyrb](https://discourse.julialang.org/u/ecyrb)\
**Replies:** 6\
**Last updated:** [March 16, 2022, 3:09pm UTC](https://discourse.julialang.org/t/juniper-integer-objective-fails-on-specific-parameters/77940 "2022-03-16T15:09:50Z")

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Simple sum-of-squares toy example, succeeds with 5 variables, stack-trace with 6 variables. I know it’s sort of a silly example, but it feels to me like the behaviour should be consistent between problem\_size = 5 and 6.…

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## [Calculate specificity (true negative rate) in crossvalidation in AutoMLPipeline](https://discourse.julialang.org/t/calculate-specificity-true-negative-rate-in-crossvalidation-in-automlpipeline/77958)

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**Author:** [@Michele\_Avanzo](https://discourse.julialang.org/u/Michele_Avanzo)\
**Replies:** 0\
**Last updated:** [March 16, 2022, 10:21am UTC](https://discourse.julialang.org/t/calculate-specificity-true-negative-rate-in-crossvalidation-in-automlpipeline/77958 "2022-03-16T10:21:08Z")

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Hi all, I am used to calculate sensitivity and specificity in classification problems. Sensitivity is recall, so not a problem, but specificity (true negative) is usually not included in evaluation metrics. Is it possi…

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## [Makie - Multi Sequence Alignment Scatterplot](https://discourse.julialang.org/t/makie-multi-sequence-alignment-scatterplot/77932)

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**Author:** [@timoleistner](https://discourse.julialang.org/u/timoleistner)\
**Replies:** 3\
**Last updated:** [March 16, 2022, 9:44am UTC](https://discourse.julialang.org/t/makie-multi-sequence-alignment-scatterplot/77932 "2022-03-16T09:44:59Z")

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Im trying to visualize a multi sequence alignment with makies scatterplot. The first idea was to overlap a heatmap with a scatterplot but I’ve found that overlapping markers with either a :rect symbol or a unicode full …

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## [Makie: Create image (as .png) of scatter projected to x-y plane?](https://discourse.julialang.org/t/makie-create-image-as-png-of-scatter-projected-to-x-y-plane/77309)

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**Author:** [@hacklint](https://discourse.julialang.org/u/hacklint)\
**Replies:** 8\
**Last updated:** [March 16, 2022, 8:20am UTC](https://discourse.julialang.org/t/makie-create-image-as-png-of-scatter-projected-to-x-y-plane/77309 "2022-03-16T08:20:45Z")

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Is there (I’m sure there is…) a way to produce an image (eg .png) of a Makie scatter plot projected “down” on the X-Y plane, ie like setting z to 0 and looking down from “sufficient height”. No perspective wanted. I’m pr…

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## [Is x-axis linking ignored in Algebra of Graphics?](https://discourse.julialang.org/t/is-x-axis-linking-ignored-in-algebra-of-graphics/76111)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 2\
**Last updated:** [March 15, 2022, 7:42pm UTC](https://discourse.julialang.org/t/is-x-axis-linking-ignored-in-algebra-of-graphics/76111 "2022-03-15T19:42:40Z")

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I want to plot a density for different groups that might have very different domains in AoG. My understanding is that in the following the x axes should be independent dd = DataFrame(x = \[rand(10)..., 10 .+ rand(10)...\]…

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## [How to debug remotecall\_wait/deserialization failures?](https://discourse.julialang.org/t/how-to-debug-remotecall-wait-deserialization-failures/77864)

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**Author:** [@jonas-schulze](https://discourse.julialang.org/u/jonas-schulze)\
**Replies:** 3\
**Last updated:** [March 15, 2022, 6:48pm UTC](https://discourse.julialang.org/t/how-to-debug-remotecall-wait-deserialization-failures/77864 "2022-03-15T18:48:00Z")

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When running code on 450 cores / 29 nodes in a Slurm environment (using the handy SlurmClusterManager.jl), sometimes everything works fine, sometimes I get failures on 1-7 workers. How do I investigate/debug/fix this? M…

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## [Disable legend in AlgebraOfGraphics](https://discourse.julialang.org/t/disable-legend-in-algebraofgraphics/77906)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 2\
**Last updated:** [March 15, 2022, 10:05am UTC](https://discourse.julialang.org/t/disable-legend-in-algebraofgraphics/77906 "2022-03-15T10:05:45Z")

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Hi everyone, is there a quick way to disable the legend for a plot created with AOG? I know that you can pass legend attributes to draw, like so: d = (;x=\[1,2,3\], y=\[1,2,3\], c=\["a", "b", "c"\]) p = data(d) \* mapping(:x…

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## [NLopt :FORCED\_STOP](https://discourse.julialang.org/t/nlopt-forced-stop/47747)

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**Author:** [@danicaratelli](https://discourse.julialang.org/u/danicaratelli)\
**Replies:** 2\
**Last updated:** [March 15, 2022, 8:57am UTC](https://discourse.julialang.org/t/nlopt-forced-stop/47747 "2022-03-15T08:57:19Z")

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Hello, I am trying to get NLopt to work but it just stops immediately and gives :FORCED\_STOP. I tried the following but it looks like the algorithm isn’t even going into \_ff. Any thoughts? Thank you! function ff(x) …

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## [Hypothesis testing in Julia](https://discourse.julialang.org/t/hypothesis-testing-in-julia/77784)

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**Author:** [@mihrits](https://discourse.julialang.org/u/mihrits)\
**Replies:** 4\
**Last updated:** [March 14, 2022, 8:29pm UTC](https://discourse.julialang.org/t/hypothesis-testing-in-julia/77784 "2022-03-14T20:29:18Z")

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I am taking a statistical data science course that is taught using R, and I am trying to replicate all the practical things in Julia. As we are doing quite basic stuff, mostly everything has been quite straightforward an…

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## [How to record loss during training with Flux.jl?](https://discourse.julialang.org/t/how-to-record-loss-during-training-with-flux-jl/77877)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 1\
**Last updated:** [March 14, 2022, 4:35pm UTC](https://discourse.julialang.org/t/how-to-record-loss-during-training-with-flux-jl/77877 "2022-03-14T16:35:05Z")

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I want to record the training-loss, along with the test-loss, during a training process. I have to compute the test-loss seperatly from the training process, but I am thinking that I should be able to hook into the train…

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## [Juniper behaviour: No incumbent when MIP feasible?](https://discourse.julialang.org/t/juniper-behaviour-no-incumbent-when-mip-feasible/77785)

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**Author:** [@ecyrb](https://discourse.julialang.org/u/ecyrb)\
**Replies:** 3\
**Last updated:** [March 14, 2022, 3:41pm UTC](https://discourse.julialang.org/t/juniper-behaviour-no-incumbent-when-mip-feasible/77785 "2022-03-14T15:41:33Z")

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I’m getting some unintuitive behaviour with Juniper (HiGHS & Ipopt). HiGHS is finding a solution that satisfies the constraints, but beyond that an incumbent solution won’t be reported and Juniper will time-out at an inf…

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## [Random access to rows of a table](https://discourse.julialang.org/t/random-access-to-rows-of-a-table/77386)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 27\
**Last updated:** [March 14, 2022, 2:06pm UTC](https://discourse.julialang.org/t/random-access-to-rows-of-a-table/77386 "2022-03-14T14:06:59Z")

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I’d like to see certain enhancements to the tabular data ecosystem, and this post is an appeal to maintainers of table-providing packages (eg, DataFrames) to articulate the form they should like these to take, or give ot…

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## [Is there a function for batch mean and std](https://discourse.julialang.org/t/is-there-a-function-for-batch-mean-and-std/77849)

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**Author:** [@GHTaarn](https://discourse.julialang.org/u/GHTaarn)\
**Replies:** 2\
**Last updated:** [March 14, 2022, 10:10am UTC](https://discourse.julialang.org/t/is-there-a-function-for-batch-mean-and-std/77849 "2022-03-14T10:10:08Z")

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Hi, Is there a package that has a function doing something similar to Batch updates for simple statistics In other words, I want to calculate std(vcat(a,b)) and know mean(a), mean(b), std(a), std(b), length(a), length(…

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## [How to use CUDA in Github CI?](https://discourse.julialang.org/t/how-to-use-cuda-in-github-ci/77855)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 2\
**Last updated:** [March 14, 2022, 10:05am UTC](https://discourse.julialang.org/t/how-to-use-cuda-in-github-ci/77855 "2022-03-14T10:05:37Z")

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Hello, I contributed some code to a package, and I made unit tests to check whether the code works on the GPU. I wrapped the code in a if CUDA.functional() ... end block and I see this: It seems like CUDA is not fun…

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## [How to use the solver-dependent callback](https://discourse.julialang.org/t/how-to-use-the-solver-dependent-callback/76519)

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**Author:** [@Jacob\_Jin](https://discourse.julialang.org/u/Jacob_Jin)\
**Replies:** 12\
**Last updated:** [March 14, 2022, 7:48am UTC](https://discourse.julialang.org/t/how-to-use-the-solver-dependent-callback/76519 "2022-03-14T07:48:26Z")

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I want to use Gurobi to implement Bender’s decomposition. I write it in Python: LB = model.cbGet(GRB.Callback.MIPSOL\_OBJBND) How to call the cbGet(GRB.Callback.MIPSOL\_OBJBND) in Julia? Thank you so much.

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## [Optimization with Gurobi](https://discourse.julialang.org/t/optimization-with-gurobi/77125)

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**Author:** [@O\_olalekan](https://discourse.julialang.org/u/O_olalekan)\
**Replies:** 4\
**Last updated:** [March 14, 2022, 1:35am UTC](https://discourse.julialang.org/t/optimization-with-gurobi/77125 "2022-03-14T01:35:36Z")

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I am solving an optimization problem with Gurobi package. I set the non-convex parameter to be 2 which helped me with the bilinear constraints. But, I am getting an infeasible solution with a warning “”" Model contains…

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## [New Distribution Stack Overflow](https://discourse.julialang.org/t/new-distribution-stack-overflow/77128)

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**Author:** [@enweg](https://discourse.julialang.org/u/enweg)\
**Replies:** 3\
**Last updated:** [March 13, 2022, 6:48pm UTC](https://discourse.julialang.org/t/new-distribution-stack-overflow/77128 "2022-03-13T18:48:40Z")

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I am currently trying to implement a distribution using the Distributions.jl interface. However, when following the guidelines mentioned here for multivariate distributions (Create New Samplers and Distributions · Distri…

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## [How to plot on a square grid with specific colours?](https://discourse.julialang.org/t/how-to-plot-on-a-square-grid-with-specific-colours/77801)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [March 13, 2022, 6:41am UTC](https://discourse.julialang.org/t/how-to-plot-on-a-square-grid-with-specific-colours/77801 "2022-03-13T06:41:29Z")

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I am trying to plot on a 2D grid the presence of “agents” (integers) on a certain plot, but I can"t get: how to associate a specific colour to a certain cell integer how to force the plot to be squared Here it is what…

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## [Functions mimic pandas apply(list)](https://discourse.julialang.org/t/functions-mimic-pandas-apply-list/77813)

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**Author:** [@Frankiewaang](https://discourse.julialang.org/u/Frankiewaang)\
**Replies:** 1\
**Last updated:** [March 13, 2022, 6:18am UTC](https://discourse.julialang.org/t/functions-mimic-pandas-apply-list/77813 "2022-03-13T06:18:42Z")

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Hi Guys, I wanna ask about the expression that could mimic python’s df.groupby("a").apply(list) And here is what the function do: ds = DataFrame(a=repeat(\[1,2\],inner=2),b='a':'j') and result should be a b 1 \[…

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## [Set MathOptInterface.SecondOrderCone is not accepted when solution method is BilevelJuMP.SOS1Mode{Float64}](https://discourse.julialang.org/t/set-mathoptinterface-secondordercone-is-not-accepted-when-solution-method-is-bileveljump-sos1mode-float64/77737)

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**Author:** [@zlq178](https://discourse.julialang.org/u/zlq178)\
**Replies:** 3\
**Last updated:** [March 13, 2022, 12:45am UTC](https://discourse.julialang.org/t/set-mathoptinterface-secondordercone-is-not-accepted-when-solution-method-is-bileveljump-sos1mode-float64/77737 "2022-03-13T00:45:12Z")

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Here is an example: using JuMP, BilevelJuMP, Gurobi model=BilevelModel(Gurobi.Optimizer) set\_optimizer\_attribute(model,"NonConvex",2) @variable(Lower(model), x) @variable(Upper(model), y) @objective(Upper(model), Min, …

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## [Could Optim.TwiceDifferentiable support CuArray?](https://discourse.julialang.org/t/could-optim-twicedifferentiable-support-cuarray/77670)

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**Author:** [@DennisFang](https://discourse.julialang.org/u/DennisFang)\
**Replies:** 5\
**Last updated:** [March 12, 2022, 7:27pm UTC](https://discourse.julialang.org/t/could-optim-twicedifferentiable-support-cuarray/77670 "2022-03-12T19:27:25Z")

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I try to transform optimization problem from CPU to GPU computing in Optim.jl. My demo examples are as follows. #Version 1-1 using Optim, CUDA f1(x) = x\[1\]^4 + x\[2\]^4 - 8 \* x\[1\] \* x\[2\] + 2.0 init = \[1.0 1.0\] opt1 = …

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## [Computing the schur norm of a matrix](https://discourse.julialang.org/t/computing-the-schur-norm-of-a-matrix/77770)

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**Author:** [@jsch77](https://discourse.julialang.org/u/jsch77)\
**Replies:** 2\
**Last updated:** [March 12, 2022, 1:11pm UTC](https://discourse.julialang.org/t/computing-the-schur-norm-of-a-matrix/77770 "2022-03-12T13:11:23Z")

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using the CVX package in Matlab the following code will compute the Schur norm of matrix T. T = \[1 2;3 4\]; n = length(T); cvx\_begin sdp quiet cvx\_precision high; variable Y0(n,n) hermitian variable Y1(n,n) …

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