# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=325

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**Page:** 326

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## [Performance issues with parallel Julia code](https://discourse.julialang.org/t/performance-issues-with-parallel-julia-code/68919)

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**Author:** [@kfrb](https://discourse.julialang.org/u/kfrb)\
**Replies:** 2\
**Last updated:** [October 29, 2021, 10:16pm UTC](https://discourse.julialang.org/t/performance-issues-with-parallel-julia-code/68919 "2021-10-29T22:16:11Z")

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I am working on a scientific code that is experiencing issues with parallelization. The parallel version is slower than the serial one and I am not sure if the right approaches are used for this application. How can I …

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## [Makie.jl: align first axis' boundary with ticklabels of second axis](https://discourse.julialang.org/t/makie-jl-align-first-axis-boundary-with-ticklabels-of-second-axis/70626)

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**Author:** [@Kevin\_Kleinbeck](https://discourse.julialang.org/u/Kevin_Kleinbeck)\
**Replies:** 2\
**Last updated:** [October 29, 2021, 9:24pm UTC](https://discourse.julialang.org/t/makie-jl-align-first-axis-boundary-with-ticklabels-of-second-axis/70626 "2021-10-29T21:24:11Z")

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I have the figure in which I want to make best use of the available space, i.e., let subfigure (a) reach the right boundary. Makie allocates space to xticklabels on the right hand side of the figures; here from the c…

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## [Algorithms for finding the self-intersection of a plane curve?](https://discourse.julialang.org/t/algorithms-for-finding-the-self-intersection-of-a-plane-curve/70192)

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**Author:** [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Replies:** 14\
**Last updated:** [October 29, 2021, 8:45pm UTC](https://discourse.julialang.org/t/algorithms-for-finding-the-self-intersection-of-a-plane-curve/70192 "2021-10-29T20:45:37Z")

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Does anyone here happen to know about algorithms for finding the self-intersection points of a plane curve? For example, find the self-intersection (X, Y) = (0, 0) in the below plane curve. Edit: Add an actual exampl…

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## [StatsModels ArgumentError: collection must be non-empty](https://discourse.julialang.org/t/statsmodels-argumenterror-collection-must-be-non-empty/69604)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 3\
**Last updated:** [October 29, 2021, 4:37pm UTC](https://discourse.julialang.org/t/statsmodels-argumenterror-collection-must-be-non-empty/69604 "2021-10-29T16:37:24Z")

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ERROR: LoadError: LoadError: ArgumentError: collection must be non-empty Stacktrace: \[1\] \_extrema\_itr(f::typeof(identity), itr::Vector{Float64}) @ Base ./operators.jl:483 \[2\] \_extrema\_dims @ ./multidimensiona…

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## [1D GAN with Flux](https://discourse.julialang.org/t/1d-gan-with-flux/54179)

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**Author:** [@davibarreira](https://discourse.julialang.org/u/davibarreira)\
**Replies:** 9\
**Last updated:** [October 29, 2021, 2:07pm UTC](https://discourse.julialang.org/t/1d-gan-with-flux/54179 "2021-10-29T14:07:27Z")

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Hey everyone. So I’ve been trying to use Flux for Generative Adversarial Networks (GAN). And unfortunately, it’s not working properly. At the moment, I’m trying to replicate a 1D GAN example (this one here 1D GAN with Ke…

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## [Using MathOptInterface with custom NL objective](https://discourse.julialang.org/t/using-mathoptinterface-with-custom-nl-objective/69823)

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**Author:** [@egvila](https://discourse.julialang.org/u/egvila)\
**Replies:** 2\
**Last updated:** [October 29, 2021, 12:51pm UTC](https://discourse.julialang.org/t/using-mathoptinterface-with-custom-nl-objective/69823 "2021-10-29T12:51:56Z")

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I am having trouble passing a custom objective function to MOI. Here’s an example: struct dumbEval \<: MOI.AbstractNLPEvaluator end e = dumbEval(); nlpBlockData = MOI.NLPBlockData(\[\], e, true); o = Ipopt.Optimizer(); …

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## [Rotatable 3D plot in jupyter](https://discourse.julialang.org/t/rotatable-3d-plot-in-jupyter/70535)

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**Author:** [@HenrikM](https://discourse.julialang.org/u/HenrikM)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 10:16am UTC](https://discourse.julialang.org/t/rotatable-3d-plot-in-jupyter/70535 "2021-10-28T10:16:24Z")

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How to make a rotatable 3D plot in Jupyter? For example, from the REPL, this works by opening a new tab in my browser: using WGLMakie let x = LinRange(-1,1,31), f(x,y) = x^2 - y^2 surface(x,x,f.(x,x')) end In the t…

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## [Combinatorial Optimization with permutation input and black-box function](https://discourse.julialang.org/t/combinatorial-optimization-with-permutation-input-and-black-box-function/70578)

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**Author:** [@duringyear](https://discourse.julialang.org/u/duringyear)\
**Replies:** 5\
**Last updated:** [October 29, 2021, 3:35am UTC](https://discourse.julialang.org/t/combinatorial-optimization-with-permutation-input-and-black-box-function/70578 "2021-10-29T03:35:32Z")

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Hi. I’ve been struggling for nights with combinatorial optimization Input = matrix with permutation. Each row represents unit, and column means visit sequence for each place. e.g) x = \[ 1 2 3 4 ; 2 3 1 4 ; 3 1 2 4 \] …

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## [Extracting the posterior mean and covariance from the object created by "GP" in GaussianProcesses.jl](https://discourse.julialang.org/t/extracting-the-posterior-mean-and-covariance-from-the-object-created-by-gp-in-gaussianprocesses-jl/70543)

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**Author:** [@path-doc](https://discourse.julialang.org/u/path-doc)\
**Replies:** 0\
**Last updated:** [October 28, 2021, 10:21am UTC](https://discourse.julialang.org/t/extracting-the-posterior-mean-and-covariance-from-the-object-created-by-gp-in-gaussianprocesses-jl/70543 "2021-10-28T10:21:24Z")

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As part of a broader Value Function Iteration exercise, I wish to feed the output of predictMVN or predict\_f back into an instantiation of GP. Eg. Suppose we have created an instance gp by feeding GP the usual ingredi…

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## [Error when mapping a CuVector{UnitRange} to index another gpu Array](https://discourse.julialang.org/t/error-when-mapping-a-cuvector-unitrange-to-index-another-gpu-array/70451)

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**Author:** [@ogoid](https://discourse.julialang.org/u/ogoid)\
**Replies:** 8\
**Last updated:** [October 28, 2021, 9:27pm UTC](https://discourse.julialang.org/t/error-when-mapping-a-cuvector-unitrange-to-index-another-gpu-array/70451 "2021-10-28T21:27:46Z")

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I’m running into an error while trying to use a CuVector{UnitRange} as an index to map another CuArray. I’m not sure if it’s a bug or not. I think I can explain it better with this example: using CUDA CUDA.allowscalar(…

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## [Getting NaNs in the hello world example of Flux](https://discourse.julialang.org/t/getting-nans-in-the-hello-world-example-of-flux/70573)

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**Author:** [@NightMachinary](https://discourse.julialang.org/u/NightMachinary)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 9:07pm UTC](https://discourse.julialang.org/t/getting-nans-in-the-hello-world-example-of-flux/70573 "2021-10-28T21:07:19Z")

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I am just starting with Flux.jl, and well, I tried their Hello World example. However, by slightly changing the input parameters used to generate the training data, the code completely fails and produces NaNs. Here is th…

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## [How can I save a Makie heatmap as PNG with one pixel per matrix element?](https://discourse.julialang.org/t/how-can-i-save-a-makie-heatmap-as-png-with-one-pixel-per-matrix-element/70579)

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**Author:** [@NiclasMattsson](https://discourse.julialang.org/u/NiclasMattsson)\
**Replies:** 1\
**Last updated:** [October 28, 2021, 8:50pm UTC](https://discourse.julialang.org/t/how-can-i-save-a-makie-heatmap-as-png-with-one-pixel-per-matrix-element/70579 "2021-10-28T20:50:33Z")

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For example: using Makie x = rand(300, 400) fig = heatmap(x) Makie.save("out1.png", fig) # 800 x 600 Makie.save("out2.png", fig, px\_per\_unit=1) # 800 x 600 Makie.save("out3.png", fig, resolution=size(x)) # 300 x 400 …

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## [MPLAPACK (multiprecision blas+lapack)](https://discourse.julialang.org/t/mplapack-multiprecision-blas-lapack/70514)

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**Author:** [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Replies:** 8\
**Last updated:** [October 28, 2021, 8:32pm UTC](https://discourse.julialang.org/t/mplapack-multiprecision-blas-lapack/70514 "2021-10-28T20:32:20Z")

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MPLAPACK works with any of these multiprecision libs: GMP, MPFR+MPC, libquadmath, and David Bailey’s DD/QD library. Here is the user guide and the repository, All BLAS routines are available using multiple precision ar…

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## [FFT is too fast compared to assignment in CUDA](https://discourse.julialang.org/t/fft-is-too-fast-compared-to-assignment-in-cuda/70353)

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**Author:** [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Replies:** 3\
**Last updated:** [October 28, 2021, 8:23pm UTC](https://discourse.julialang.org/t/fft-is-too-fast-compared-to-assignment-in-cuda/70353 "2021-10-28T20:23:29Z")

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FFT is a pretty fast algorithm, but its performance on CUDA seems even comparable to simple element-wise assignment. I am wondering if this is something expected. Here is the contents of a performance test code named t…

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## [Using splines in a likelihood](https://discourse.julialang.org/t/using-splines-in-a-likelihood/49340)

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**Author:** [@Ross\_Boylan](https://discourse.julialang.org/u/Ross_Boylan)\
**Replies:** 0\
**Last updated:** [October 30, 2020, 10:47pm UTC](https://discourse.julialang.org/t/using-splines-in-a-likelihood/49340 "2020-10-30T22:47:27Z")

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I am looking to add splines to the type of functions that can go in @formula to support a conditional likelihood model I’ve developed. Once that is working I plan to add automatic smoothing parameter selection. The pac…

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## [Weird Schrodinger solution by DifferentialEquations.jl versus time interval](https://discourse.julialang.org/t/weird-schrodinger-solution-by-differentialequations-jl-versus-time-interval/70542)

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**Author:** [@TravellingLight6](https://discourse.julialang.org/u/TravellingLight6)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 12:53pm UTC](https://discourse.julialang.org/t/weird-schrodinger-solution-by-differentialequations-jl-versus-time-interval/70542 "2021-10-28T12:53:16Z")

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Suppose we want to solve a simple schrodinger equation under columb potential,namely, \\Psi''=(V-E)\\Psi and V(r)=-\\frac{1}{r}, The wavefunction u(r) of ground state is: \\sim a\\times r\\cdot e^{-br} which should be the ex…

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## [How to help nonlinear solvers by applying bounds](https://discourse.julialang.org/t/how-to-help-nonlinear-solvers-by-applying-bounds/70484)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 11\
**Last updated:** [October 28, 2021, 9:59am UTC](https://discourse.julialang.org/t/how-to-help-nonlinear-solvers-by-applying-bounds/70484 "2021-10-28T09:59:24Z")

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Apart from IntervalRootFinding.jl, is there a way to “help” the solvers by providing bounds on the unknown variables? eg is there a way to inform NLsolve.jl or NonlinearSolvers.jl that x\[i\] \>= 0 so that the solver does n…

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## [Object Detection with YOLOv3 and PlotlyJS](https://discourse.julialang.org/t/object-detection-with-yolov3-and-plotlyjs/70540)

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**Author:** [@cepel](https://discourse.julialang.org/u/cepel)\
**Replies:** 0\
**Last updated:** [October 28, 2021, 9:42am UTC](https://discourse.julialang.org/t/object-detection-with-yolov3-and-plotlyjs/70540 "2021-10-28T09:42:21Z")

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Hey everyone! I have developed a Dash Julia application for object detection (with ObjectDetector.jl, using Flux backend). You can enter an image URL, adjust detection and overlap thresholds, and plot the image with bou…

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## [Implementation of Jacobi method not yielding acurate results](https://discourse.julialang.org/t/implementation-of-jacobi-method-not-yielding-acurate-results/70511)

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**Author:** [@scaredFish](https://discourse.julialang.org/u/scaredFish)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 9:17am UTC](https://discourse.julialang.org/t/implementation-of-jacobi-method-not-yielding-acurate-results/70511 "2021-10-28T09:17:37Z")

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Hello, I am fairly new to the language and i have tried to implement the Jacobi method. However, this has not given me the expected results. The solution should be (1,2,-1,1) and the returned values at convergence are (…

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## [Multinode scaling](https://discourse.julialang.org/t/multinode-scaling/70503)

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**Author:** [@Antonis\_Skourtis](https://discourse.julialang.org/u/Antonis_Skourtis)\
**Replies:** 2\
**Last updated:** [October 28, 2021, 8:25am UTC](https://discourse.julialang.org/t/multinode-scaling/70503 "2021-10-28T08:25:50Z")

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Hello, While I was experimenting with the Distributed library I ran into some issue. I am trying to utilize multiple nodes on a given cluster using Slurm but as of yet I cannot get it working. My script.jl is quite sim…

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## [Guide to RESTful Webservices](https://discourse.julialang.org/t/guide-to-restful-webservices/70350)

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**Author:** [@vmuser](https://discourse.julialang.org/u/vmuser)\
**Replies:** 6\
**Last updated:** [October 28, 2021, 6:21am UTC](https://discourse.julialang.org/t/guide-to-restful-webservices/70350 "2021-10-28T06:21:03Z")

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My company is currently switching our core application from Python to Julia. The application is used as a RESTful web service by other internal web services which are exposed to our clients. Everything goes smooth so fa…

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## ["error in running finalizer" in CSV.jl](https://discourse.julialang.org/t/error-in-running-finalizer-in-csv-jl/70513)

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**Author:** [@gleyland](https://discourse.julialang.org/u/gleyland)\
**Replies:** 3\
**Last updated:** [October 27, 2021, 11:59pm UTC](https://discourse.julialang.org/t/error-in-running-finalizer-in-csv-jl/70513 "2021-10-27T23:59:53Z")

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Hi, When using CSV.Rows from CSV 0.9.4 repeatedly (using Revise to re-run a test), I get a: error in running finalizer: Base.IOError(msg="unlink("\<home\>\\\\AppData\\\\Local\\\\Temp\\\\1\\\\jl\_9056.tmp"): permission denied (EACCE…

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## [Flux.train error: no method matching back!(::Float64)](https://discourse.julialang.org/t/flux-train-error-no-method-matching-back-float64/31956)

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**Author:** [@janak](https://discourse.julialang.org/u/janak)\
**Replies:** 4\
**Last updated:** [October 27, 2021, 7:41pm UTC](https://discourse.julialang.org/t/flux-train-error-no-method-matching-back-float64/31956 "2021-10-27T19:41:14Z")

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I am working with Julia 1.2.0 on Jupyter lab on Windows 10 machine. I am using the following package versions: DiffEqFlux : v0.8.1 DifferentialEquations: v6.8.0 Flux: v0.9.0 I am trying to train a neural network usi…

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## [Unrolling of loops with operations on CuArrays](https://discourse.julialang.org/t/unrolling-of-loops-with-operations-on-cuarrays/70468)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 4\
**Last updated:** [October 27, 2021, 5:10pm UTC](https://discourse.julialang.org/t/unrolling-of-loops-with-operations-on-cuarrays/70468 "2021-10-27T17:10:42Z")

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I have a loop where at each iteration I do some vectorial operation over CuArray. For example using CUDA N = 4 a = ones(N) u = CUDA.zeros(1000) @. u = a\[1\] for i=2:N @. u += a\[i\] end As far as I understand, in t…

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## [Linear equation with integer digits solution](https://discourse.julialang.org/t/linear-equation-with-integer-digits-solution/70479)

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**Author:** [@Dan\_Micsa](https://discourse.julialang.org/u/Dan_Micsa)\
**Replies:** 3\
**Last updated:** [October 27, 2021, 3:12pm UTC](https://discourse.julialang.org/t/linear-equation-with-integer-digits-solution/70479 "2021-10-27T15:12:15Z")

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I’m new to Julia and I want tot solve this problem with integer, digits solutions: “Each letter represents a different non-zero digit: SEE + SEE = AXES” I create this code and returns an inaccurate solution: using JuM…

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## [Confusion on DifferentialEquations.jl. How many saved timesteps](https://discourse.julialang.org/t/confusion-on-differentialequations-jl-how-many-saved-timesteps/70409)

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**Author:** [@DerOzean](https://discourse.julialang.org/u/DerOzean)\
**Replies:** 5\
**Last updated:** [October 27, 2021, 11:00am UTC](https://discourse.julialang.org/t/confusion-on-differentialequations-jl-how-many-saved-timesteps/70409 "2021-10-27T11:00:42Z")

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Hello everyone, I’m working on a dynamic food web and solving some differential equations. As solver I’m using the DP5 monte carlo method. After successful solving the problem I get for every time steps 4 time the same…

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## [Optim Control the number of search steps during an iteration](https://discourse.julialang.org/t/optim-control-the-number-of-search-steps-during-an-iteration/70457)

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**Author:** [@phy-lxf](https://discourse.julialang.org/u/phy-lxf)\
**Replies:** 0\
**Last updated:** [October 27, 2021, 7:44am UTC](https://discourse.julialang.org/t/optim-control-the-number-of-search-steps-during-an-iteration/70457 "2021-10-27T07:44:57Z")

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When optim.jl uses L-BFGS method to optimize the objective function, the derivative between each step of the optimization process often needs to search 3-4 steps. Can we fix the search step number to 1?

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## [Save solution and warm start](https://discourse.julialang.org/t/save-solution-and-warm-start/70315)

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**Author:** [@Brock](https://discourse.julialang.org/u/Brock)\
**Replies:** 1\
**Last updated:** [October 27, 2021, 4:50am UTC](https://discourse.julialang.org/t/save-solution-and-warm-start/70315 "2021-10-27T04:50:49Z")

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I am using JuMP and CPLEX to solve an optimization problem. How can I save the best solution found after a certain time limit to a file? How can I then use this file as a warm start during another attempt to solve the …

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## [How to get plot parameters?](https://discourse.julialang.org/t/how-to-get-plot-parameters/70440)

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**Author:** [@pjgorski](https://discourse.julialang.org/u/pjgorski)\
**Replies:** 1\
**Last updated:** [October 27, 2021, 12:13am UTC](https://discourse.julialang.org/t/how-to-get-plot-parameters/70440 "2021-10-27T00:13:10Z")

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We have the plot. Is there a way to get (lookup) plot parameters? Why do I want it? My goal is to create a master legend for subplots. So I need the legend labels to create an empty plot with legend only and I’d like to…

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## [Find if point is within geojson polygons](https://discourse.julialang.org/t/find-if-point-is-within-geojson-polygons/70416)

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**Author:** [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)\
**Replies:** 3\
**Last updated:** [October 26, 2021, 10:47pm UTC](https://discourse.julialang.org/t/find-if-point-is-within-geojson-polygons/70416 "2021-10-26T22:47:36Z")

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I am slowly dipping my toe into the Julia waters and I’m hoping someone could point me in the right direction as to how I can determine if a point falls within any of the polygons defined by a geojson file. I’ve found Ge…

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