# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=396

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**Page:** 397

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## [DataFrames show() ignores column width, prints everything](https://discourse.julialang.org/t/dataframes-show-ignores-column-width-prints-everything/53327)

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**Author:** [@xyz1](https://discourse.julialang.org/u/xyz1)\
**Replies:** 3\
**Last updated:** [January 14, 2021, 8:38pm UTC](https://discourse.julialang.org/t/dataframes-show-ignores-column-width-prints-everything/53327 "2021-01-14T20:38:12Z")

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Hi, I’m using DataFrames with IJulia and when I create a DataFrame and then “show” it, instead of truncation like in Python it shows all columns non-truncated, which obviously hangs always. I’ve tried setting ENV\[“COLUMN…

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## [Interactive visualization of multidimensional array](https://discourse.julialang.org/t/interactive-visualization-of-multidimensional-array/53356)

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**Author:** [@ElOceanografo](https://discourse.julialang.org/u/ElOceanografo)\
**Replies:** 0\
**Last updated:** [January 14, 2021, 8:34pm UTC](https://discourse.julialang.org/t/interactive-visualization-of-multidimensional-array/53356 "2021-01-14T20:34:39Z")

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I’ve got a 3D array, representing vector-valued observations at each location on a 2D grid. I’d like to find a way to plot this array so that one subplot shows a spatial slice, while a second subplot shows the data valu…

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## [Makie does not display when mesh function is called in a loop](https://discourse.julialang.org/t/makie-does-not-display-when-mesh-function-is-called-in-a-loop/35983)

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**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 5\
**Last updated:** [January 14, 2021, 8:16pm UTC](https://discourse.julialang.org/t/makie-does-not-display-when-mesh-function-is-called-in-a-loop/35983 "2021-01-14T20:16:20Z")

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I wrote a Makie function to draw several meshes in the same window but couldn’t get anything to display. Eventually simplified to the problem to this: if the Makie.mesh! function is called in a loop nothing displays, eve…

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## [DiffEqFlux GPU example slow](https://discourse.julialang.org/t/diffeqflux-gpu-example-slow/53336)

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**Author:** [@acse-ogb119](https://discourse.julialang.org/u/acse-ogb119)\
**Replies:** 3\
**Last updated:** [January 14, 2021, 1:53pm UTC](https://discourse.julialang.org/t/diffeqflux-gpu-example-slow/53336 "2021-01-14T13:53:11Z")

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I copy and paste the DiffEqFlux.jl GPU example, slap in an @time on the sciml\_train call at the end and spin it up. The runtime is reported on my system as around 38 seconds. I then edit the example to be fully CPU, and…

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## [How to close a remote Timer?](https://discourse.julialang.org/t/how-to-close-a-remote-timer/53295)

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**Author:** [@Christian\_Dengler](https://discourse.julialang.org/u/Christian_Dengler)\
**Replies:** 3\
**Last updated:** [January 14, 2021, 7:47am UTC](https://discourse.julialang.org/t/how-to-close-a-remote-timer/53295 "2021-01-14T07:47:27Z")

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I want to run mutliple procedures in parallel on a server in fixed time ntervals. The idea was to ,e.g., simply use “@spawnat :any” together with “Timer”, however, I cannot find a way to stop the Timer once its started. …

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## [Need advice when data almost (but not quite) fit log normal dist](https://discourse.julialang.org/t/need-advice-when-data-almost-but-not-quite-fit-log-normal-dist/53287)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 7\
**Last updated:** [January 13, 2021, 6:38pm UTC](https://discourse.julialang.org/t/need-advice-when-data-almost-but-not-quite-fit-log-normal-dist/53287 "2021-01-13T18:38:37Z")

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This isn’t really a question about Julia so maybe this should be tagged as Offtopic, but I’m working with a data set that has several series of data that all closely follow a log normal distribution, but not quite. The p…

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## [Optim.jl wrongly reporting success](https://discourse.julialang.org/t/optim-jl-wrongly-reporting-success/53174)

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**Author:** [@Albert\_Zevelev](https://discourse.julialang.org/u/Albert_Zevelev)\
**Replies:** 4\
**Last updated:** [January 13, 2021, 6:44pm UTC](https://discourse.julialang.org/t/optim-jl-wrongly-reporting-success/53174 "2021-01-13T18:44:17Z")

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I’m solving for the MLE. using Distributions, Random, Optim; DGP\_True = LogNormal(17,7); Random.seed!(123); const d\_train = rand(DGP\_True, 1\_000) const d\_test = rand(DGP\_True, 1\_000) # LogNormal function loglike(θ) …

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## [Tensor contractions with symmetries](https://discourse.julialang.org/t/tensor-contractions-with-symmetries/52980)

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**Author:** [@Nellatur](https://discourse.julialang.org/u/Nellatur)\
**Replies:** 3\
**Last updated:** [January 13, 2021, 4:48pm UTC](https://discourse.julialang.org/t/tensor-contractions-with-symmetries/52980 "2021-01-13T16:48:12Z")

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I have some tensor contractions, e.g., A\[abcd\] B\[cdef\] = C\[abef\], where A\[abcd\] = A\[badc\] and B\[cdef\] = B\[dcfe\]. I did not find information about symmetry in einsum in NumPy. Is there any Julia package can handle tensor …

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## [Gradient error in Flux model inputs](https://discourse.julialang.org/t/gradient-error-in-flux-model-inputs/53259)

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**Author:** [@Elmo](https://discourse.julialang.org/u/Elmo)\
**Replies:** 5\
**Last updated:** [January 13, 2021, 4:13pm UTC](https://discourse.julialang.org/t/gradient-error-in-flux-model-inputs/53259 "2021-01-13T16:13:54Z")

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Hi all, I am trying to construct a loss function in Flux that is composed of a typical mean squared error component, as well as a derivative component. For some reason I get a Can't differentiate foreigncall expression e…

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## [How to find the index of a Dense Axis Array?](https://discourse.julialang.org/t/how-to-find-the-index-of-a-dense-axis-array/53204)

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**Author:** [@fredih](https://discourse.julialang.org/u/fredih)\
**Replies:** 3\
**Last updated:** [January 13, 2021, 12:35pm UTC](https://discourse.julialang.org/t/how-to-find-the-index-of-a-dense-axis-array/53204 "2021-01-13T12:35:46Z")

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Hello! I know I can use something like findall(x-\>x==1, myArray) to find the indices of elements of value 1 inside myArray. However, my variables in my optimization problem are DenseAxisArrays, as they are indexed with…

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## [Move a plane with slider in Makie.jl](https://discourse.julialang.org/t/move-a-plane-with-slider-in-makie-jl/53258)

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**Author:** [@Flausi](https://discourse.julialang.org/u/Flausi)\
**Replies:** 0\
**Last updated:** [January 12, 2021, 10:06pm UTC](https://discourse.julialang.org/t/move-a-plane-with-slider-in-makie-jl/53258 "2021-01-12T22:06:53Z")

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Hello, I tried to use Makie.jl to move a layer in a spatial plot via a slider and update the data depending on how the slider is set. This actually works quite well, but the layer is not moved with the ‘transformation -…

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## [Take gradient of parameters not working](https://discourse.julialang.org/t/take-gradient-of-parameters-not-working/53250)

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**Author:** [@Elmo](https://discourse.julialang.org/u/Elmo)\
**Replies:** 0\
**Last updated:** [January 12, 2021, 8:20pm UTC](https://discourse.julialang.org/t/take-gradient-of-parameters-not-working/53250 "2021-01-12T20:20:58Z")

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Hi all! I am trying to construct a loss function in Flux (v0.11.2) that regularizes the parameters relative to some number (not 0). Below is a minimal working example, does anybody know why the gradients are nothing? us…

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## [SingularSpectrumAnalysis and CPU load](https://discourse.julialang.org/t/singularspectrumanalysis-and-cpu-load/53212)

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**Author:** [@Colin\_Beckingham](https://discourse.julialang.org/u/Colin_Beckingham)\
**Replies:** 3\
**Last updated:** [January 12, 2021, 6:09pm UTC](https://discourse.julialang.org/t/singularspectrumanalysis-and-cpu-load/53212 "2021-01-12T18:09:21Z")

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SSA does a good job of extracting trend and seasonality from a time series. However widening the window on a large dataset puts quite a load on my CPU (GPU is too old to contribute to calculation in Julia) heats up my CP…

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## [CUDA.jl Differentiation Error](https://discourse.julialang.org/t/cuda-jl-differentiation-error/53011)

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**Author:** [@Honza9723](https://discourse.julialang.org/u/Honza9723)\
**Replies:** 5\
**Last updated:** [January 12, 2021, 1:28pm UTC](https://discourse.julialang.org/t/cuda-jl-differentiation-error/53011 "2021-01-12T13:28:17Z")

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Dear All, while working on my project (epidemic model, solved using PINN), I tried to port my code to GPU. While function (loss function of my neural network) works and delivers reasonable speed up, while computing grad…

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## [Second derivative of shape functions in JuAFEM](https://discourse.julialang.org/t/second-derivative-of-shape-functions-in-juafem/53160)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 3\
**Last updated:** [January 12, 2021, 8:56am UTC](https://discourse.julialang.org/t/second-derivative-of-shape-functions-in-juafem/53160 "2021-01-12T08:56:23Z")

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Hi, is there already a implemented function, which computes the second derivatives of the shape function at a given point? I am working with PDEs of higher-order and therefore need high order derivates of the used ansa…

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## [DiffEq tolerances on ContinuousCallbacks?](https://discourse.julialang.org/t/diffeq-tolerances-on-continuouscallbacks/53181)

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**Author:** [@klaff](https://discourse.julialang.org/u/klaff)\
**Replies:** 7\
**Last updated:** [January 12, 2021, 6:49am UTC](https://discourse.julialang.org/t/diffeq-tolerances-on-continuouscallbacks/53181 "2021-01-12T06:49:12Z")

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I’m troubleshooting some friction models and trying to understand what I’m seeing. I’ve made a MWE by taking the bouncing ball model from the DiffEq docs and changing the coefficient of restitution to 0.1 instead of 1.0 …

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## [How can I set and get the session of the request from browser in Genie.jl?](https://discourse.julialang.org/t/how-can-i-set-and-get-the-session-of-the-request-from-browser-in-genie-jl/52883)

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**Author:** [@AquaIndigo](https://discourse.julialang.org/u/AquaIndigo)\
**Replies:** 6\
**Last updated:** [January 12, 2021, 4:36am UTC](https://discourse.julialang.org/t/how-can-i-set-and-get-the-session-of-the-request-from-browser-in-genie-jl/52883 "2021-01-12T04:36:58Z")

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Hello, I’m doing my Database course project using Genie as the back-end server, and I’m wondering how to set and save the session. And my efforts are as follows: route("/api/login") do uid = haskey(@params, :id) ? @p…

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## [PyCall.jl with PermutedDimsArray, StridedSubArray, and ReinterperetArray](https://discourse.julialang.org/t/pycall-jl-with-permuteddimsarray-stridedsubarray-and-reinterperetarray/53146)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 2\
**Last updated:** [January 12, 2021, 12:06am UTC](https://discourse.julialang.org/t/pycall-jl-with-permuteddimsarray-stridedsubarray-and-reinterperetarray/53146 "2021-01-12T00:06:00Z")

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I have been working on Napari.jl which is a Julia package for Napari, a multidimensional image viewer written in Python developed at Chan-Zuckerberg Initiative’s Biohub with many contributors from the field of biological…

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## [Is it a good time for a PyTorch developer to move to Julia? If so, Flux? Knet?](https://discourse.julialang.org/t/is-it-a-good-time-for-a-pytorch-developer-to-move-to-julia-if-so-flux-knet/38453)

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**Author:** [@Alon](https://discourse.julialang.org/u/Alon)\
**Replies:** 52\
**Last updated:** [January 11, 2021, 9:51pm UTC](https://discourse.julialang.org/t/is-it-a-good-time-for-a-pytorch-developer-to-move-to-julia-if-so-flux-knet/38453 "2021-01-11T21:51:35Z")

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For me, the move from Keras to PyTorch was the best decision in my AI career. I am considering moving from Python to Julia because of performance and because the “NumPy” is built-in (as it was in Matlab rest its soul). …

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## [Poor linear relaxation](https://discourse.julialang.org/t/poor-linear-relaxation/53170)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 1\
**Last updated:** [January 11, 2021, 8:12pm UTC](https://discourse.julialang.org/t/poor-linear-relaxation/53170 "2021-01-11T20:12:20Z")

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Dear users, I have a MIP problem whose linear relaxation is very poor. Observe the report of CPLEX below: (Gap greater to 999.99%, then the symbol “–”). Does have any parameter in CPLEX to set to improve these perf…

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## [Having a hard time visualizing LazySets.HPolyHedron & HPolytope](https://discourse.julialang.org/t/having-a-hard-time-visualizing-lazysets-hpolyhedron-hpolytope/52721)

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**Author:** [@adropintheriver](https://discourse.julialang.org/u/adropintheriver)\
**Replies:** 1\
**Last updated:** [January 11, 2021, 6:10pm UTC](https://discourse.julialang.org/t/having-a-hard-time-visualizing-lazysets-hpolyhedron-hpolytope/52721 "2021-01-11T18:10:28Z")

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Q.1 what is the right way to render the following a. HPolyhedron/HPolytope b. Set of points (3D) so the code below from Polyhedra docs A = rand(HPolyhedron,dim=3) HPoly = Polytope(constraints\_list(A)) remove\_redunda…

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## [Last mile of BlackBoxOptim](https://discourse.julialang.org/t/last-mile-of-blackboxoptim/53171)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 0\
**Last updated:** [January 11, 2021, 6:05pm UTC](https://discourse.julialang.org/t/last-mile-of-blackboxoptim/53171 "2021-01-11T18:05:17Z")

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I am doing Monte Carlo study of the simulated method of moments estimator for my economic model. Since the objective function is not differentiable, I am using adaptive\_de\_rand\_1\_bin\_radiuslimited in BlackBoxOptim.jl as …

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## [Why are vertices of every LazySets.VPolygon or VPolytope given as 1 D Array and not based on the shape of the object?](https://discourse.julialang.org/t/why-are-vertices-of-every-lazysets-vpolygon-or-vpolytope-given-as-1-d-array-and-not-based-on-the-shape-of-the-object/52719)

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**Author:** [@adropintheriver](https://discourse.julialang.org/u/adropintheriver)\
**Replies:** 1\
**Last updated:** [January 11, 2021, 5:49pm UTC](https://discourse.julialang.org/t/why-are-vertices-of-every-lazysets-vpolygon-or-vpolytope-given-as-1-d-array-and-not-based-on-the-shape-of-the-object/52719 "2021-01-11T17:49:32Z")

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A = rand(HPolyhedron,dim=3) Av = tovrep(A) Av.vertices gives an 11-element Array{Array{Float64,1},1} and not a 3 Dimensional array of 11 elements, also how can i convert these vertices to BasicGeometry.Point3d without u…

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## [Why I get 'RefValue{SubArray{Int64' and not "simply" 'SubArray{Int64'](https://discourse.julialang.org/t/why-i-get-refvalue-subarray-int64-and-not-simply-subarray-int64/52286)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 13\
**Last updated:** [January 11, 2021, 4:42pm UTC](https://discourse.julialang.org/t/why-i-get-refvalue-subarray-int64-and-not-simply-subarray-int64/52286 "2021-01-11T16:42:01Z")

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I have this in these cases of single columns df = DataFrame(x = \[1, 1, 2, 2\], y = \[1, 2, 101, 102\]); gd = groupby(df, :x); julia\> combine(gd,:x=\>(X-\>Ref(X))=\>:rx) 2×2 DataFrame Row │ x rx │ Int64 Su…

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## [Can't compile a GPU kernel function for =\>](https://discourse.julialang.org/t/cant-compile-a-gpu-kernel-function-for/53100)

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**Author:** [@Stephan\_Meyn](https://discourse.julialang.org/u/Stephan_Meyn)\
**Replies:** 2\
**Last updated:** [January 11, 2021, 10:36am UTC](https://discourse.julialang.org/t/cant-compile-a-gpu-kernel-function-for/53100 "2021-01-11T10:36:55Z")

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I’m trying to persuade CUDA.jl to compile a kernel function. After reducing the issue I have come to this sample code using CUDA x=Float32(2.0) knots =CuArray{Float32,1}(\[1.2, 2.0, 3.0\]) mapOp(v::Float32)::Int = v \>= x…

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## [What shape should data be in to perform a linear fit with GLM?](https://discourse.julialang.org/t/what-shape-should-data-be-in-to-perform-a-linear-fit-with-glm/53120)

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**Author:** [@alice](https://discourse.julialang.org/u/alice)\
**Replies:** 7\
**Last updated:** [January 11, 2021, 9:22am UTC](https://discourse.julialang.org/t/what-shape-should-data-be-in-to-perform-a-linear-fit-with-glm/53120 "2021-01-11T09:22:15Z")

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I am trying to fit some data with a variable number of dimensions using a linear fit. I am currently trying to use GLM, but I am happy to use any other library. I’ve been running in to a lot of trouble getting the data …

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## [Using Julia to solve semidefinite programming problem that has vector solutions](https://discourse.julialang.org/t/using-julia-to-solve-semidefinite-programming-problem-that-has-vector-solutions/53134)

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**Author:** [@cheng\_chen](https://discourse.julialang.org/u/cheng_chen)\
**Replies:** 6\
**Last updated:** [January 11, 2021, 6:50am UTC](https://discourse.julialang.org/t/using-julia-to-solve-semidefinite-programming-problem-that-has-vector-solutions/53134 "2021-01-11T06:50:02Z")

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Hi everyone! I need to use Julia to solve a SDP. What would you suggest to use to solve the SDP? I tried Convex and JuMP with ProxSDP, I couldn’t get it to work.

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## [Errors during test CUDA](https://discourse.julialang.org/t/errors-during-test-cuda/53142)

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**Author:** [@youeh1](https://discourse.julialang.org/u/youeh1)\
**Replies:** 0\
**Last updated:** [January 11, 2021, 6:09am UTC](https://discourse.julialang.org/t/errors-during-test-cuda/53142 "2021-01-11T06:09:42Z")

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Hi, I just format my labtop and install graphics drivers CUDA 11.2 julia (1.53) I added CUDA.jl and downloaded cuDNN111 via artifact and had no errors by here. I ran Pkg\> test CUDA, now I got errors ┌ Error: Excep…

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## [Suppress license output from solver in JuMP.Model](https://discourse.julialang.org/t/suppress-license-output-from-solver-in-jump-model/20828)

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**Author:** [@torgo](https://discourse.julialang.org/u/torgo)\
**Replies:** 13\
**Last updated:** [January 11, 2021, 1:24am UTC](https://discourse.julialang.org/t/suppress-license-output-from-solver-in-jump-model/20828 "2021-01-11T01:24:41Z")

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using JuMP, Gurobi m = Model(solver=GurobiSolver(OutputFlag=0)) I have a program where the second line gets called frequently. Every time it does, this gets printed to stdout: Academic license - for non-commercial use…

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## [ForwardDiff.jl \\ Optim.jl and recompilation for any vector size](https://discourse.julialang.org/t/forwarddiff-jl-optim-jl-and-recompilation-for-any-vector-size/53104)

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**Author:** [@PharmCat](https://discourse.julialang.org/u/PharmCat)\
**Replies:** 4\
**Last updated:** [January 10, 2021, 5:54pm UTC](https://discourse.julialang.org/t/forwarddiff-jl-optim-jl-and-recompilation-for-any-vector-size/53104 "2021-01-10T17:54:21Z")

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I try to optimize function with different variable vector size. And I think that for each task type method is compilated again. Main function is type-stable as I think by @code\_warntype and @code\_typed. And probably eac…

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