# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=487

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**Page:** 488

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## [Solving a cplex model via JuMP and java](https://discourse.julialang.org/t/solving-a-cplex-model-via-jump-and-java/26646)

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**Author:** [@healyp](https://discourse.julialang.org/u/healyp)\
**Replies:** 10\
**Last updated:** [August 2, 2019, 9:55am UTC](https://discourse.julialang.org/t/solving-a-cplex-model-via-jump-and-java/26646 "2019-08-02T09:55:24Z")

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A colleague and I both implemented a model we have been working on, him using a java interface to cplex and me using JuMP. After spending some time to reconcile the .lp outputs of the two models I genuinely believe that…

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## [How to plot y axis in log form, with differential equations?](https://discourse.julialang.org/t/how-to-plot-y-axis-in-log-form-with-differential-equations/27073)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 7\
**Last updated:** [August 2, 2019, 9:13am UTC](https://discourse.julialang.org/t/how-to-plot-y-axis-in-log-form-with-differential-equations/27073 "2019-08-02T09:13:21Z")

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Hello, I would like advice on how to plot the results of differential equations in log format. I have searched the forums and the Plot.jl manual but cannot find an example. I would like to plot the y-axis in log format…

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## [How to get the number of tracked parameters?](https://discourse.julialang.org/t/how-to-get-the-number-of-tracked-parameters/27096)

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**Author:** [@tue](https://discourse.julialang.org/u/tue)\
**Replies:** 4\
**Last updated:** [August 2, 2019, 5:05am UTC](https://discourse.julialang.org/t/how-to-get-the-number-of-tracked-parameters/27096 "2019-08-02T05:05:35Z")

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I’m sure there is a way to get the number of tracked parameters by Flux.Tracker, but so far I still haven’t found any way of actually getting this number. Suppose I make the following: forward = Chain( Conv((5,5), …

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## [Redis Support?](https://discourse.julialang.org/t/redis-support/27013)

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**Author:** [@Samuel\_Stapleton](https://discourse.julialang.org/u/Samuel_Stapleton)\
**Replies:** 1\
**Last updated:** [August 2, 2019, 3:50am UTC](https://discourse.julialang.org/t/redis-support/27013 "2019-08-02T03:50:04Z")

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There were previous discussions to move Redis.jl to JuliaDatabases and to tag a version that supports Julia 1.0, but it appears that the package author never heard back about this original request. Are there plans to con…

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## [Sparse cholesky factorization with user permutation (Julia 1.1)](https://discourse.julialang.org/t/sparse-cholesky-factorization-with-user-permutation-julia-1-1/27080)

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**Author:** [@JuhaHeiskala](https://discourse.julialang.org/u/JuhaHeiskala)\
**Replies:** 1\
**Last updated:** [August 1, 2019, 7:53pm UTC](https://discourse.julialang.org/t/sparse-cholesky-factorization-with-user-permutation-julia-1-1/27080 "2019-08-01T19:53:08Z")

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The sparse cholesky factorization does not generally keep the user permutation given as parameter. SuiteSparse performs post ordering which is not disabled (as far as I can tell) in the current Julia interface to SuiteS…

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## [Data storage/loading for data produced by algorithms and metadata](https://discourse.julialang.org/t/data-storage-loading-for-data-produced-by-algorithms-and-metadata/27029)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 4\
**Last updated:** [August 1, 2019, 10:58am UTC](https://discourse.julialang.org/t/data-storage-loading-for-data-produced-by-algorithms-and-metadata/27029 "2019-08-01T10:58:57Z")

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Hi, I am sorry, if this question was answered somewhere else already or there is a package especially for my need but the more I searched for solutions to my problem the more confused I got. I have algorithms producing…

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## [Using sparse matrix in NLoptimization](https://discourse.julialang.org/t/using-sparse-matrix-in-nloptimization/27046)

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**Author:** [@Dota](https://discourse.julialang.org/u/Dota)\
**Replies:** 3\
**Last updated:** [August 1, 2019, 6:09am UTC](https://discourse.julialang.org/t/using-sparse-matrix-in-nloptimization/27046 "2019-08-01T06:09:21Z")

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Hi, I’m new to julia, nowadays I’m trying to use JuMP to do NLoptimization, which I used to use fmincon() in matlab. In my problem I will have a 1\*144 matrix as input: model=Model(with\_optimizer(Ipopt.Optimizer)) @…

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## [Error of using Dagger, according to the manual](https://discourse.julialang.org/t/error-of-using-dagger-according-to-the-manual/27011)

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**Author:** [@zhangliye](https://discourse.julialang.org/u/zhangliye)\
**Replies:** 1\
**Last updated:** [August 1, 2019, 12:24am UTC](https://discourse.julialang.org/t/error-of-using-dagger-according-to-the-manual/27011 "2019-08-01T00:24:39Z")

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I tried Dagger according to the manual and got some errors. using Dagger using Distributed addprocs(3) @everywhere function f1(v1::Float64, v2::Float64) r = 0. for i in 1:10^7 r += sin(v1) + sin(v2) …

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## [(Gtk) Interface designed with GLADE, the registered function for button click event is not being called](https://discourse.julialang.org/t/gtk-interface-designed-with-glade-the-registered-function-for-button-click-event-is-not-being-called/26958)

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**Author:** [@mantzaris](https://discourse.julialang.org/u/mantzaris)\
**Replies:** 1\
**Last updated:** [July 31, 2019, 8:51pm UTC](https://discourse.julialang.org/t/gtk-interface-designed-with-glade-the-registered-function-for-button-click-event-is-not-being-called/26958 "2019-07-31T20:51:57Z")

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I am using GLADE to develop an interface that gets built afterwards by Gtk.jl, and the interface layout appears with all of the labels and buttons after it is built in my Julia code. Within GLADE, for the the ‘button’ ob…

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## [Stiff SDE and \`DiffEq\`](https://discourse.julialang.org/t/stiff-sde-and-diffeq/26851)

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**Author:** [@jacob-roth](https://discourse.julialang.org/u/jacob-roth)\
**Replies:** 5\
**Last updated:** [July 31, 2019, 7:20pm UTC](https://discourse.julialang.org/t/stiff-sde-and-diffeq/26851 "2019-07-31T19:20:59Z")

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I’m trying to integrate an SDE with constant, additive, diagonal noise and a “stiff” drift component (the ODE component comes from a singularly perturbed DAE system…). I need to be able to integrate indefinitely (I’m int…

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## [First-order linear system with time delay as DDEProblem?](https://discourse.julialang.org/t/first-order-linear-system-with-time-delay-as-ddeproblem/27014)

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**Author:** [@joshualeond](https://discourse.julialang.org/u/joshualeond)\
**Replies:** 3\
**Last updated:** [July 31, 2019, 5:19pm UTC](https://discourse.julialang.org/t/first-order-linear-system-with-time-delay-as-ddeproblem/27014 "2019-07-31T17:19:45Z")

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I’m new to the diffeq landscape and am working on solving a First Order Plus Dead Time (FOPDT) model: \\tau\_p \\frac{dy(t)}{dt} = -y(t) + K\_p u\\left(t-\\theta\_p\\right) I have data for y(t) and data for u(t) and am havi…

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## [Network structural balance analysis in Julia](https://discourse.julialang.org/t/network-structural-balance-analysis-in-julia/27045)

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**Author:** [@kcyb](https://discourse.julialang.org/u/kcyb)\
**Replies:** 0\
**Last updated:** [July 31, 2019, 5:19pm UTC](https://discourse.julialang.org/t/network-structural-balance-analysis-in-julia/27045 "2019-07-31T17:19:31Z")

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Dear Julia community, I have a question regarding network analysis in Julia. I apologize if this is the wrong section, I couldn’t decide for a better one. Are you aware of any packages for sound network structural balan…

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## [Assigning JuMP VariableRef to an array position](https://discourse.julialang.org/t/assigning-jump-variableref-to-an-array-position/26216)

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**Author:** [@MuadhF](https://discourse.julialang.org/u/MuadhF)\
**Replies:** 6\
**Last updated:** [July 31, 2019, 4:56pm UTC](https://discourse.julialang.org/t/assigning-jump-variableref-to-an-array-position/26216 "2019-07-31T16:56:37Z")

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Hi, Is it possible to assign a decision variable to an array position? For example: using JuMP m = Model() @variable(m, x) arr = zeros(100) arr\[1\] = x x is a decision variable which will be decided by the model whe…

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## [Managing large dataset in package intended for beginners use](https://discourse.julialang.org/t/managing-large-dataset-in-package-intended-for-beginners-use/26936)

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**Author:** [@Zach\_Christensen](https://discourse.julialang.org/u/Zach_Christensen)\
**Replies:** 13\
**Last updated:** [July 31, 2019, 12:57pm UTC](https://discourse.julialang.org/t/managing-large-dataset-in-package-intended-for-beginners-use/26936 "2019-07-31T12:57:36Z")

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Background I’m working on a package that’s primarily for accessing a specific and large data set. I want part of its functionality to involve summary information (basic stats and plots) on subsections of the data. I cur…

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## [Writing stencils for CuArray](https://discourse.julialang.org/t/writing-stencils-for-cuarray/26562)

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**Author:** [@platawiec](https://discourse.julialang.org/u/platawiec)\
**Replies:** 6\
**Last updated:** [July 31, 2019, 3:19pm UTC](https://discourse.julialang.org/t/writing-stencils-for-cuarray/26562 "2019-07-31T15:19:54Z")

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I am adapting a PDE solver to work on GPU. Being lazy, I was hoping that something like using CuArrays A = rand(5, 5, 5) |\> CuArray{Float64} B = similar(A) Is = CartesianIndices((2:4, 2:4)) @views @. B\[Is.indices..., :…

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## [Distributions.jl interop for probprog](https://discourse.julialang.org/t/distributions-jl-interop-for-probprog/26912)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 17\
**Last updated:** [July 31, 2019, 7:28am UTC](https://discourse.julialang.org/t/distributions-jl-interop-for-probprog/26912 "2019-07-31T07:28:15Z")

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For probabilistic programming in particular, it’s critical to be able to use distribution-related functions (especially logpdf) in non-standard ways. For example, I would love to be able to call logpdf(TDist(nu),x) where…

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## [Mean function unknown](https://discourse.julialang.org/t/mean-function-unknown/26844)

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**Author:** [@Diego](https://discourse.julialang.org/u/Diego)\
**Replies:** 4\
**Last updated:** [July 30, 2019, 4:57pm UTC](https://discourse.julialang.org/t/mean-function-unknown/26844 "2019-07-30T16:57:15Z")

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After adding and importing the Statistics package Julia still does not recognize the mean function, any ideas?

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## [Help with JuMP 0.19 upgrade and performance hits](https://discourse.julialang.org/t/help-with-jump-0-19-upgrade-and-performance-hits/21214)

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**Author:** [@Libbum](https://discourse.julialang.org/u/Libbum)\
**Replies:** 8\
**Last updated:** [July 30, 2019, 4:00pm UTC](https://discourse.julialang.org/t/help-with-jump-0-19-upgrade-and-performance-hits/21214 "2019-07-30T16:00:52Z")

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Hi all, I’m having some issues with Ipopt not finding a solution with a script I’m updating to Julia 1.1 / JuMP 0.19 from a functioning one on Julia 0.64 / JuMP 0.18. Unsure exactly where the problem is, so I’ve put th…

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## [Difference in sparsity pattern caused by @NLconstraint and @constraint in JuMP](https://discourse.julialang.org/t/difference-in-sparsity-pattern-caused-by-nlconstraint-and-constraint-in-jump/26919)

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**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\
**Replies:** 4\
**Last updated:** [July 30, 2019, 1:48am UTC](https://discourse.julialang.org/t/difference-in-sparsity-pattern-caused-by-nlconstraint-and-constraint-in-jump/26919 "2019-07-30T01:48:32Z")

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Hi all, I am solving a nonlinear problem using JuMP and IPOPT. All my constraints are linear or degree 2 polynomials. I firstly try to add nonlinear constraints using @NLconstraint and here is the summary of IPOPT Thi…

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## [Easiest way to live plot?](https://discourse.julialang.org/t/easiest-way-to-live-plot/26929)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 14\
**Last updated:** [July 29, 2019, 1:36pm UTC](https://discourse.julialang.org/t/easiest-way-to-live-plot/26929 "2019-07-29T13:36:29Z")

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Hey guys, so I have this case; I am running a simulation program which at every time steps outputs a data file, which I then strip for data - I would like to do this and showcase it with a live plot but I am struggling a…

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## [Couenne no results - seems stuck](https://discourse.julialang.org/t/couenne-no-results-seems-stuck/26879)

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**Author:** [@Raminel](https://discourse.julialang.org/u/Raminel)\
**Replies:** 2\
**Last updated:** [July 28, 2019, 6:27pm UTC](https://discourse.julialang.org/t/couenne-no-results-seems-stuck/26879 "2019-07-28T18:27:52Z")

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Hi all, I am using Couenne for my MINLP problem. I have a problem using Couenne when I add a nonlinear term to the objective. I have tried different options in the couenne.opt file based on different posts here, still n…

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## [JuMP Parameters params depend on the Optimizer?](https://discourse.julialang.org/t/jump-parameters-params-depend-on-the-optimizer/26725)

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**Author:** [@remi-garcia](https://discourse.julialang.org/u/remi-garcia)\
**Replies:** 4\
**Last updated:** [July 28, 2019, 9:38am UTC](https://discourse.julialang.org/t/jump-parameters-params-depend-on-the-optimizer/26725 "2019-07-28T09:38:41Z")

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Hi, With JuMP we can pass parameters to the solver in with\_optimizer. What I understood is that the parameter depend on the used Optimizer. If I want a Time Limit with GLPK I’ll use tm\_lim while with CPLEX it’ll be CPX\_…

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## [A new JuMPTutorials.jl package](https://discourse.julialang.org/t/a-new-jumptutorials-jl-package/26900)

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**Author:** [@Arpit\_Bhatia](https://discourse.julialang.org/u/Arpit_Bhatia)\
**Replies:** 0\
**Last updated:** [July 28, 2019, 3:06am UTC](https://discourse.julialang.org/t/a-new-jumptutorials-jl-package/26900 "2019-07-28T03:06:30Z")

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Hi, I am Arpit, a GSoC student working under @chriscoey, @joaquimg and Lea Kapelevich to create a new JuMPTutorials.jl package, which will contain tidied, updated, and more-consistent versions of many of the notebooks i…

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## [Setting constraints as lazy with JuMP 0.19 and Gurobi](https://discourse.julialang.org/t/setting-constraints-as-lazy-with-jump-0-19-and-gurobi/24516)

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**Author:** [@fa-bien](https://discourse.julialang.org/u/fa-bien)\
**Replies:** 7\
**Last updated:** [July 27, 2019, 7:15pm UTC](https://discourse.julialang.org/t/setting-constraints-as-lazy-with-jump-0-19-and-gurobi/24516 "2019-07-27T19:15:04Z")

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I build a mixed-integer model with JuMP and Gurobi. I want to set certain constraints as lazy. With JuMP 0.18 I was using the solution described here: Lazy constraints at root node? · Issue #1226 · jump-dev/JuMP.jl · Git…

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## [How to reuse object in multiple parallel calls instead of making copies in each call](https://discourse.julialang.org/t/how-to-reuse-object-in-multiple-parallel-calls-instead-of-making-copies-in-each-call/26891)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 0\
**Last updated:** [July 27, 2019, 6:47pm UTC](https://discourse.julialang.org/t/how-to-reuse-object-in-multiple-parallel-calls-instead-of-making-copies-in-each-call/26891 "2019-07-27T18:47:44Z")

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I’m using pmap() to make a large number (~12000) of parallel calls to perform power flow computations based on the pseudocode below: ''' PD, QD are K x N matrices where N ~= 12000 and K = number of loads in current case…

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## [Display animation created with Luxor in jupyter notebook](https://discourse.julialang.org/t/display-animation-created-with-luxor-in-jupyter-notebook/26839)

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**Author:** [@karlroyen](https://discourse.julialang.org/u/karlroyen)\
**Replies:** 2\
**Last updated:** [July 27, 2019, 6:34am UTC](https://discourse.julialang.org/t/display-animation-created-with-luxor-in-jupyter-notebook/26839 "2019-07-27T06:34:26Z")

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Can I display an animation created with Luxor in a jupyter notebook? For example if I put something like the example code for animation using Colors, Luxor demo = Movie(400, 400, "test") function backdrop(scene, frame…

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## [Distributions package invlogcdf() function returning the wrong answer?](https://discourse.julialang.org/t/distributions-package-invlogcdf-function-returning-the-wrong-answer/26867)

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**Author:** [@dataSurfer](https://discourse.julialang.org/u/dataSurfer)\
**Replies:** 2\
**Last updated:** [July 27, 2019, 12:39am UTC](https://discourse.julialang.org/t/distributions-package-invlogcdf-function-returning-the-wrong-answer/26867 "2019-07-27T00:39:21Z")

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Consider that the following answer: invlogcdf(Chi(11), log(0.975)) # 4.681885225101231 qchisq(0.975, 11) # 21.920049261021205 is wrong when comparing invlogcdf() to the equivalent R function, but the following is corre…

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## [Global optimization: Simulated Method of Moments](https://discourse.julialang.org/t/global-optimization-simulated-method-of-moments/23844)

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**Author:** [@drarnau](https://discourse.julialang.org/u/drarnau)\
**Replies:** 9\
**Last updated:** [July 26, 2019, 4:36pm UTC](https://discourse.julialang.org/t/global-optimization-simulated-method-of-moments/23844 "2019-07-26T16:36:12Z")

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I work with non-linear models that need to be calibrated to match data moments. The setup is simple. I have a function that takes a set of parameters as input (for example, a vector of floats), solves the model, and retu…

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## ["Textbook" use of pmap but strange execution times](https://discourse.julialang.org/t/textbook-use-of-pmap-but-strange-execution-times/26852)

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**Author:** [@mgiugliano](https://discourse.julialang.org/u/mgiugliano)\
**Replies:** 0\
**Last updated:** [July 26, 2019, 4:15pm UTC](https://discourse.julialang.org/t/textbook-use-of-pmap-but-strange-execution-times/26852 "2019-07-26T16:15:28Z")

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I have 28 cores and 56 threads and I call julia with “-p auto”. When starting from a (non-parallel) example, @time for x in \[10;ones(Int, 10)\] sleep(x/10); println(x) end its execution time (~2s) makes perfect se…

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## [Problem building CUDAnative](https://discourse.julialang.org/t/problem-building-cudanative/26540)

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**Author:** [@vargonis](https://discourse.julialang.org/u/vargonis)\
**Replies:** 2\
**Last updated:** [July 26, 2019, 7:29am UTC](https://discourse.julialang.org/t/problem-building-cudanative/26540 "2019-07-26T07:29:41Z")

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Hi there. I’m trying to setup Julia to use CuArrays. I have Julia 1.0.4 and the cuda toolkit 10.1, on Pop!\_OS. I’m doing (on the REPL) ENV\["LD\_LIBRARY\_PATH"\] = "/usr/lib/cuda/lib64" ENV\["CUDA\_PATH"\] = "/usr/lib/cuda" u…

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