# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=187

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**Page:** 188

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## [Sampling from a probability distribution on GPU](https://discourse.julialang.org/t/sampling-from-a-probability-distribution-on-gpu/94389)

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**Author:** [@ArjunNarayanan](https://discourse.julialang.org/u/ArjunNarayanan)\
**Replies:** 13\
**Last updated:** [June 13, 2023, 12:52pm UTC](https://discourse.julialang.org/t/sampling-from-a-probability-distribution-on-gpu/94389 "2023-06-13T12:52:00Z")

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I’m interested in doing something like using Distributions: Categorical using CUDA p = cu(\[0.7,0.2,0.1\]) idx = rand(Categorical(p)) Is there a way to sample from a vector of probability masses on the GPU? This kind of…

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## [We don't know how to parse constraints containing expressions of type :generator](https://discourse.julialang.org/t/we-dont-know-how-to-parse-constraints-containing-expressions-of-type-generator/100270)

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**Author:** [@A.Marx](https://discourse.julialang.org/u/A.Marx)\
**Replies:** 3\
**Last updated:** [June 13, 2023, 8:53am UTC](https://discourse.julialang.org/t/we-dont-know-how-to-parse-constraints-containing-expressions-of-type-generator/100270 "2023-06-13T08:53:49Z")

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I am trying to set up the following dispatch optimization problem. However, the capacity constraints gives me the error: \`@constraint(m, \[t in time\], (cfD\[:p\] \>= y\[p, t\] for p = plants))\`: Unsupported constraint express…

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## [Running neural ODE on measurement](https://discourse.julialang.org/t/running-neural-ode-on-measurement/100179)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 7\
**Last updated:** [June 13, 2023, 6:33am UTC](https://discourse.julialang.org/t/running-neural-ode-on-measurement/100179 "2023-06-13T06:33:43Z")

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I am trying get a neural ODE working, that doesn’t have a function/ode as input but a measurement. I want to apply the neural ODE to get the original function expressed by the measurement and not the derivative. I am t…

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## [How to troubleshoot ForwardDiff](https://discourse.julialang.org/t/how-to-troubleshoot-forwarddiff/99728)

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**Author:** [@johnb](https://discourse.julialang.org/u/johnb)\
**Replies:** 18\
**Last updated:** [June 12, 2023, 10:05pm UTC](https://discourse.julialang.org/t/how-to-troubleshoot-forwarddiff/99728 "2023-06-12T22:05:45Z")

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I’ve been trying to write a loss function for a PDE that I’m solving in order to identify parameters and I would like to use the gradient of my loss function in parameter optimization. Unfortunately, ForwardDiff returns …

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## [Building random generator for custom type to generate a specific number of variates](https://discourse.julialang.org/t/building-random-generator-for-custom-type-to-generate-a-specific-number-of-variates/100199)

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**Author:** [@atteson](https://discourse.julialang.org/u/atteson)\
**Replies:** 2\
**Last updated:** [June 12, 2023, 2:14pm UTC](https://discourse.julialang.org/t/building-random-generator-for-custom-type-to-generate-a-specific-number-of-variates/100199 "2023-06-12T14:14:02Z")

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I’m writing a random generator for a custom type and, for this type, it is important to know the number of variates being generated for efficient generation. My thought is to generalize Random.Repitition to allow Val{n}…

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## [Doing repeated Euler-steps in a simulation, Differentialequations.jl](https://discourse.julialang.org/t/doing-repeated-euler-steps-in-a-simulation-differentialequations-jl/100221)

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**Author:** [@Martin](https://discourse.julialang.org/u/Martin)\
**Replies:** 5\
**Last updated:** [June 12, 2023, 12:55pm UTC](https://discourse.julialang.org/t/doing-repeated-euler-steps-in-a-simulation-differentialequations-jl/100221 "2023-06-12T12:55:43Z")

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Hi! I am researcher working with problems related to optimal stopping/switching problems, and I have an issue where I need to, in a for loop, advance one time step (size dt) of an SDE for lots of previous states. And I …

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## [How to add names to a collection of constraints in JuMP using @constraints](https://discourse.julialang.org/t/how-to-add-names-to-a-collection-of-constraints-in-jump-using-constraints/100130)

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**Author:** [@JackaChou](https://discourse.julialang.org/u/JackaChou)\
**Replies:** 4\
**Last updated:** [June 12, 2023, 6:37am UTC](https://discourse.julialang.org/t/how-to-add-names-to-a-collection-of-constraints-in-jump-using-constraints/100130 "2023-06-12T06:37:21Z")

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I want to name different kinds of constraints for enhancing readability and debugging, what’s the right syntax to do it with @constraints, I know this is easy for @constraint(, base\_name = “Name”). Below is my code with…

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## [Change the number of particles in the PF dynamically](https://discourse.julialang.org/t/change-the-number-of-particles-in-the-pf-dynamically/100195)

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**Author:** [@josemanuel22](https://discourse.julialang.org/u/josemanuel22)\
**Replies:** 0\
**Last updated:** [June 11, 2023, 5:55pm UTC](https://discourse.julialang.org/t/change-the-number-of-particles-in-the-pf-dynamically/100195 "2023-06-11T17:55:29Z")

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I am trying to create a particle filter method where the number of particles is adaptive, meaning it changes dynamically depending on whether the method is converging or not. I want to take inspiration from the repositor…

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## [Truncated chi-square returning NaNs](https://discourse.julialang.org/t/truncated-chi-square-returning-nans/100187)

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**Author:** [@Jad\_Zeitouni](https://discourse.julialang.org/u/Jad_Zeitouni)\
**Replies:** 0\
**Last updated:** [June 11, 2023, 2:48pm UTC](https://discourse.julialang.org/t/truncated-chi-square-returning-nans/100187 "2023-06-11T14:48:42Z")

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I’m trying to sample from a truncated chi-square distribution, defined over \[0, a\], by using the following line of code. rand(Truncated(Chisq(n), 0, a)) This does alright most of the time, but sometimes it returns NaNs…

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## [Modelling heating curves with a PINN](https://discourse.julialang.org/t/modelling-heating-curves-with-a-pinn/99521)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 6\
**Last updated:** [June 11, 2023, 1:32pm UTC](https://discourse.julialang.org/t/modelling-heating-curves-with-a-pinn/99521 "2023-06-11T13:32:25Z")

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I am Trying to model some temperature curves with a physically informed NN (PINN). I the physical model I am trying to apply is an FOPDT. NN = Chain( Dense(1 =\> 32, tanh), Dense(32 =\> 32, tanh), Den…

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## [How to plot a spectrum with dB as y-axis with PythonPlot](https://discourse.julialang.org/t/how-to-plot-a-spectrum-with-db-as-y-axis-with-pythonplot/100172)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [June 11, 2023, 8:01am UTC](https://discourse.julialang.org/t/how-to-plot-a-spectrum-with-db-as-y-axis-with-pythonplot/100172 "2023-06-11T08:01:15Z")

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I am using PythonPlot and want to have a logarithmic y axis formatted in dezibel (dB). In Python I could use the following code: from UliEngineering.Math.Decibel import \* import matplotlib.ticker as mtick def decibel\_fo…

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## [Meaning of Incidence matrix?](https://discourse.julialang.org/t/meaning-of-incidence-matrix/100141)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [June 11, 2023, 5:05am UTC](https://discourse.julialang.org/t/meaning-of-incidence-matrix/100141 "2023-06-11T05:05:45Z")

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I defined a nonlinear model and linearized it. I get the following result: julia\> simplified\_sys Model sys with 3 equations States (3): ω(t) \[defaults to 1.04286\] Uest(t) \[defaults to 9.0\] Pgc(t) \[defaults to 2.46…

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## [GeoMakie: Could not find font regular, using TeX Gyre Heros Makie](https://discourse.julialang.org/t/geomakie-could-not-find-font-regular-using-tex-gyre-heros-makie/100092)

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**Author:** [@thunderclouds](https://discourse.julialang.org/u/thunderclouds)\
**Replies:** 4\
**Last updated:** [June 11, 2023, 12:24am UTC](https://discourse.julialang.org/t/geomakie-could-not-find-font-regular-using-tex-gyre-heros-makie/100092 "2023-06-11T00:24:32Z")

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I have a question about the fonts in GeoMakie.jl. When I run the following sample code, I get the error “Warning: Could not find font regular, using TeX Gyre Heros Makie”. It seems that this error occurs at the timing w…

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## [Maximum timestep in DIfferential solver](https://discourse.julialang.org/t/maximum-timestep-in-differential-solver/100135)

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**Author:** [@Sarthak\_Choudhury](https://discourse.julialang.org/u/Sarthak_Choudhury)\
**Replies:** 4\
**Last updated:** [June 10, 2023, 5:11pm UTC](https://discourse.julialang.org/t/maximum-timestep-in-differential-solver/100135 "2023-06-10T17:11:19Z")

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Hi, I am currently solving an ODE in DifferentialEquations.jl which has explicit time dependence. I arrive at a solution for a larger time t\_{max} with the solution saved at 1000 time points in between. Now I want to zo…

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## [Is there a symbolic Integrator](https://discourse.julialang.org/t/is-there-a-symbolic-integrator/100140)

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**Author:** [@bombadil224](https://discourse.julialang.org/u/bombadil224)\
**Replies:** 1\
**Last updated:** [June 10, 2023, 4:47pm UTC](https://discourse.julialang.org/t/is-there-a-symbolic-integrator/100140 "2023-06-10T16:47:17Z")

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I have been writing a Homotopy approximation method solver for differential equations. This requires the use of integration, So far I have been using a very simple function for the integration of polynomials. This is cle…

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## [Counting in dataframes](https://discourse.julialang.org/t/counting-in-dataframes/99907)

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**Author:** [@optimist](https://discourse.julialang.org/u/optimist)\
**Replies:** 7\
**Last updated:** [June 7, 2023, 1:49pm UTC](https://discourse.julialang.org/t/counting-in-dataframes/99907 "2023-06-07T13:49:21Z")

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I have a dataframe in which I need to count the number of occurences of values in a given list. Suppose I have a dataframe df: df= DataFrame(:B1 =\> \[1,1,2,2,3,4,5\], :B2 =\> \[1,7,7,2,2,5,5\],:B3 =\> \[2,2,2,3,3,3,3\] ) 7×3 …

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## [MCMC Sampling Method Overview/Comparison?](https://discourse.julialang.org/t/mcmc-sampling-method-overview-comparison/88496)

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**Author:** [@Alec\_Loudenback](https://discourse.julialang.org/u/Alec_Loudenback)\
**Replies:** 7\
**Last updated:** [June 10, 2023, 5:50am UTC](https://discourse.julialang.org/t/mcmc-sampling-method-overview-comparison/88496 "2023-06-10T05:50:19Z")

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Is there a reference that compares the different sampling techniques available for Turing.jl? I don’t see a consistently preferred chain and it’s not clear to me (a beginner bayesian) why one would prefer a given sampler…

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## [Very large performance difference between Turing and Stan \[Gaussian Process\]](https://discourse.julialang.org/t/very-large-performance-difference-between-turing-and-stan-gaussian-process/93663)

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**Author:** [@jdossgollin](https://discourse.julialang.org/u/jdossgollin)\
**Replies:** 9\
**Last updated:** [June 10, 2023, 5:42am UTC](https://discourse.julialang.org/t/very-large-performance-difference-between-turing-and-stan-gaussian-process/93663 "2023-06-10T05:42:59Z")

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A student I’m working with is working on a Gaussian Process model in Turing, but it was very slow. Out of frustration, they reimplemented in stan and it’s much faster. For context, it fits (1000 samples from 1 chain) in …

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## [Warning: Linking two modules of different target triples: 'bcloader' ... 'start'](https://discourse.julialang.org/t/warning-linking-two-modules-of-different-target-triples-bcloader-start/93864)

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**Author:** [@albheim](https://discourse.julialang.org/u/albheim)\
**Replies:** 5\
**Last updated:** [June 10, 2023, 4:28am UTC](https://discourse.julialang.org/t/warning-linking-two-modules-of-different-target-triples-bcloader-start/93864 "2023-06-10T04:28:18Z")

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Started getting the warnings warning: Linking two modules of different target triples: 'bcloader' is 'x86\_64-unknown-linux-gnu' whereas 'start' is 'x86\_64-linux-gnu' warning: Linking two modules of different target tri…

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## [Simple Enzyme AD on CUDA GPU](https://discourse.julialang.org/t/simple-enzyme-ad-on-cuda-gpu/99966)

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**Author:** [@Thaegy](https://discourse.julialang.org/u/Thaegy)\
**Replies:** 5\
**Last updated:** [June 9, 2023, 11:00pm UTC](https://discourse.julialang.org/t/simple-enzyme-ad-on-cuda-gpu/99966 "2023-06-09T23:00:08Z")

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Hi there, I have just started thinking about moving some of my JAX code to Julia and wanted to have a go using Enzyme for my AD. I am looking to make use of CUDA GPUs. I have started with a simple program to verify thin…

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## [Instability detected in solving ODE with DifferentialEquations.jl](https://discourse.julialang.org/t/instability-detected-in-solving-ode-with-differentialequations-jl/99792)

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**Author:** [@Rezair](https://discourse.julialang.org/u/Rezair)\
**Replies:** 7\
**Last updated:** [June 9, 2023, 10:23pm UTC](https://discourse.julialang.org/t/instability-detected-in-solving-ode-with-differentialequations-jl/99792 "2023-06-09T22:23:22Z")

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I am trying to solve an equation in Julia but I get Unstable retcode, I have solved the same eqaution in MATLAB with no issues. here is a simplified version of the code: using DifferentialEquations struct RosslerMSF …

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## [Perform Bayesian estimations of ODE parameters when variables were not measured simultaneously](https://discourse.julialang.org/t/perform-bayesian-estimations-of-ode-parameters-when-variables-were-not-measured-simultaneously/100033)

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**Author:** [@zeyang.sun](https://discourse.julialang.org/u/zeyang.sun)\
**Replies:** 3\
**Last updated:** [June 9, 2023, 10:08pm UTC](https://discourse.julialang.org/t/perform-bayesian-estimations-of-ode-parameters-when-variables-were-not-measured-simultaneously/100033 "2023-06-09T22:08:27Z")

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Greetings everyone! Recently I need to use Bayesian method to estimate the parameters of a chemical kinetic model which can be described by ordinary differential equations. I found Turing.jl or DiffeqBayes.jl might be t…

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## [How to get live plotting of data into gui](https://discourse.julialang.org/t/how-to-get-live-plotting-of-data-into-gui/100115)

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**Author:** [@blckbart](https://discourse.julialang.org/u/blckbart)\
**Replies:** 0\
**Last updated:** [June 9, 2023, 3:57pm UTC](https://discourse.julialang.org/t/how-to-get-live-plotting-of-data-into-gui/100115 "2023-06-09T15:57:34Z")

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Hi All, I am looking for a good example GUI made using glade and GTK. Specifically I want to be able to live update a plot. Any help would be appreciated. Thanks!

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## [Getting 3D shapes without illumination](https://discourse.julialang.org/t/getting-3d-shapes-without-illumination/100091)

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**Author:** [@peremato](https://discourse.julialang.org/u/peremato)\
**Replies:** 5\
**Last updated:** [June 9, 2023, 2:45pm UTC](https://discourse.julialang.org/t/getting-3d-shapes-without-illumination/100091 "2023-06-09T14:45:28Z")

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I am plotting with GLMakie my own 3D solids by defining GeometryBasics.faces(...) and GeometryBasics.coordinates(...) for each type. Then I plot the solids using a code like this: m = GeometryBasics.mesh(solid) po…

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## [Laguerre polynomials on GPU](https://discourse.julialang.org/t/laguerre-polynomials-on-gpu/99571)

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**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 27\
**Last updated:** [June 9, 2023, 11:35am UTC](https://discourse.julialang.org/t/laguerre-polynomials-on-gpu/99571 "2023-06-09T11:35:19Z")

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Hello, I’m currently able to calculate the generalized Laguerre polynomials on the CPU using HypergeometricFunctions \_genlaguerre(n, α, x) = binomial(n+α,n) \* HypergeometricFunctions.M(-n, α+1, x) A = rand(1000, 1000)…

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## [Resume chains Turing](https://discourse.julialang.org/t/resume-chains-turing/66282)

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**Author:** [@marcobonici](https://discourse.julialang.org/u/marcobonici)\
**Replies:** 12\
**Last updated:** [June 9, 2023, 8:13am UTC](https://discourse.julialang.org/t/resume-chains-turing/66282 "2023-06-09T08:13:21Z")

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Hi to everybody, I want to use Turing on the lsf cluster of my university. Following the official documentation and using the ClusterManager package I was able to run Turing on my cluster. using Turing using Distribute…

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## [How to find Shadow Price in JuMP](https://discourse.julialang.org/t/how-to-find-shadow-price-in-jump/99887)

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**Author:** [@Gagan\_Meena](https://discourse.julialang.org/u/Gagan_Meena)\
**Replies:** 6\
**Last updated:** [June 9, 2023, 4:38am UTC](https://discourse.julialang.org/t/how-to-find-shadow-price-in-jump/99887 "2023-06-09T04:38:47Z")

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How to find the shadow price for the equality constraint in the following code? using JuMP, Gurobi include("Data.jl") Market\_dt = PlanningData function Market\_Clearing(Market\_dt) # Sets and Indices n …

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## [An optimization problem on GPU works in Julia v1.8, but does not work in v1.9](https://discourse.julialang.org/t/an-optimization-problem-on-gpu-works-in-julia-v1-8-but-does-not-work-in-v1-9/100036)

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**Author:** [@DennisFang](https://discourse.julialang.org/u/DennisFang)\
**Replies:** 2\
**Last updated:** [June 9, 2023, 4:19am UTC](https://discourse.julialang.org/t/an-optimization-problem-on-gpu-works-in-julia-v1-8-but-does-not-work-in-v1-9/100036 "2023-06-09T04:19:47Z")

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Hello, I’m doing an optimization problem and trying to work on CUDA. I can run my program in Julia v1.8.2 and v1.8.5. However, I get some errors when running on the GPU in Julia v1.9.0 and v1.9.1. Here is a minimum exa…

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## [ODE solvers - Matlab ode23s vs Rosenbrock23 implementations](https://discourse.julialang.org/t/ode-solvers-matlab-ode23s-vs-rosenbrock23-implementations/99950)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 5\
**Last updated:** [June 8, 2023, 9:15pm UTC](https://discourse.julialang.org/t/ode-solvers-matlab-ode23s-vs-rosenbrock23-implementations/99950 "2023-06-08T21:15:20Z")

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I am working on solving stiff ODEs and I was comparing MATLAB and Julia solvers. While both give the same solution when the system reaches a steady state, at the beginning there is a small difference for the same relativ…

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## [Cannot build CPLEX even with correct environment variable](https://discourse.julialang.org/t/cannot-build-cplex-even-with-correct-environment-variable/87234)

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**Author:** [@Richard0416](https://discourse.julialang.org/u/Richard0416)\
**Replies:** 5\
**Last updated:** [June 8, 2023, 9:14pm UTC](https://discourse.julialang.org/t/cannot-build-cplex-even-with-correct-environment-variable/87234 "2023-06-08T21:14:33Z")

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Hello! I am trying to add CPLEX to Julia. I download the latest version of CPLEX, 22.1 And also updated the CPLEX.jl package to the latest version, v0.9.4. When running Pkg.build(“CPLEX”), it seems that the path is wron…

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