# Specific Domains **URL:** https://discourse.julialang.org/c/domain/10.md?page=550 [Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md) **Page:** 551 --- ## [Change objective coefficient iteratively for SOCP with quadratic objective](https://discourse.julialang.org/t/change-objective-coefficient-iteratively-for-socp-with-quadratic-objective/7090)
**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\ **Replies:** 0\ **Last updated:** [November 15, 2017, 7:57pm UTC](https://discourse.julialang.org/t/change-objective-coefficient-iteratively-for-socp-with-quadratic-objective/7090 "2017-11-15T19:57:59Z")
Hi all, I am trying to write a program that will need to iteratively solve some problem with linear and second-order cone constraints and (minimize) quadratic objective function. To be more specific, at each iteration t… --- ## [Atomic block in @async](https://discourse.julialang.org/t/atomic-block-in-async/7076)
**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\ **Replies:** 2\ **Last updated:** [November 15, 2017, 2:02am UTC](https://discourse.julialang.org/t/atomic-block-in-async/7076 "2017-11-15T02:02:04Z")
I am using my own version of pmap as described here: https://docs.julialang.org/en/stable/manual/parallel-computing#Synchronization-With-Remote-References-1 Is there a way to run some block atomically? I have an array… --- ## [Constraint involving numerical integration](https://discourse.julialang.org/t/constraint-involving-numerical-integration/7043)
**Author:** [@MaximilianJHuber](https://discourse.julialang.org/u/MaximilianJHuber)\ **Replies:** 3\ **Last updated:** [November 14, 2017, 3:47pm UTC](https://discourse.julialang.org/t/constraint-involving-numerical-integration/7043 "2017-11-14T15:47:39Z")
Hi! I try to write up a minimization problem with 5+131 variables, a quadratic objective involving the last 131 variables and 131 constraints that involve a numerical integration using Gauss-Hermite nodes. The variables… --- ## [Gantt Chart](https://discourse.julialang.org/t/gantt-chart/6988)
**Author:** [@Rahul\_Sharma](https://discourse.julialang.org/u/Rahul_Sharma)\ **Replies:** 9\ **Last updated:** [November 14, 2017, 10:59am UTC](https://discourse.julialang.org/t/gantt-chart/6988 "2017-11-14T10:59:03Z")
Hello, I want to draw a gnatt chart for a particular schedule using Gadfly. I have the start times of all products for a given machine and also its processing times. Can you please tell me how to do that? Thanks! --- ## [C callback for GSL](https://discourse.julialang.org/t/c-callback-for-gsl/7058)
**Author:** [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)\ **Replies:** 1\ **Last updated:** [November 14, 2017, 6:41am UTC](https://discourse.julialang.org/t/c-callback-for-gsl/7058 "2017-11-14T06:41:03Z")
I would like to add fixed points quadrature to GSL.jl and to understand how callbacks for GSL work, I read the blog post as linked in the documentation. Here is the code for Gauss-Legendre adaptive quadrature routine th… --- ## [How to check if Plots.jl is installed and loaded?](https://discourse.julialang.org/t/how-to-check-if-plots-jl-is-installed-and-loaded/7047)
**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\ **Replies:** 12\ **Last updated:** [November 14, 2017, 6:02am UTC](https://discourse.julialang.org/t/how-to-check-if-plots-jl-is-installed-and-loaded/7047 "2017-11-14T06:02:11Z")
I am writing a function that generates a plot. In case Plots.jl is not installed on the user’s machine or in case it is not loaded in the current Julia session I’d like to print a warning. What is a good way to achieve t… --- ## [Get\_variable with initializer xavier](https://discourse.julialang.org/t/get-variable-with-initializer-xavier/7042)
**Author:** [@Colin\_Beckingham](https://discourse.julialang.org/u/Colin_Beckingham)\ **Replies:** 1\ **Last updated:** [November 13, 2017, 3:04pm UTC](https://discourse.julialang.org/t/get-variable-with-initializer-xavier/7042 "2017-11-13T15:04:30Z")
I’m trying to emulate a python call to get\_variable() in Julia: Python: tf.get\_variable(name,size,initializer=tf.contrib.layers.xavier\_initializer(seed = 0)) Julia: get\_variable(size,…?..) but not getting the xavier… --- ## [JuMP sum variables with arbitrary set of indices](https://discourse.julialang.org/t/jump-sum-variables-with-arbitrary-set-of-indices/7024)
**Author:** [@Rafal\_Machalica](https://discourse.julialang.org/u/Rafal_Machalica)\ **Replies:** 3\ **Last updated:** [November 12, 2017, 12:55pm UTC](https://discourse.julialang.org/t/jump-sum-variables-with-arbitrary-set-of-indices/7024 "2017-11-12T12:55:54Z")
Hello, I’m trying to write a constraint with sum of variables with irregular indexes pattern. With regular indices it works fine: using JuMP m = Model() @variable(m, x\[1:100, 1:100\]) @constraint(m, sum(x\[i, j\] for i =… --- ## [Limitation in CuArrays](https://discourse.julialang.org/t/limitation-in-cuarrays/7011)
**Author:** [@Skoffer](https://discourse.julialang.org/u/Skoffer)\ **Replies:** 1\ **Last updated:** [November 11, 2017, 8:06pm UTC](https://discourse.julialang.org/t/limitation-in-cuarrays/7011 "2017-11-11T20:06:34Z")
What is the reason for this limitation in CuArrays? When broadcasting, watch out for errors like: julia\> sin.(cos.(xs)) ERROR: CUDA error: invalid program counter (code #718, ERROR\_INVALID\_PC) A current limitation of … --- ## [Error using sum in DistributedArrays](https://discourse.julialang.org/t/error-using-sum-in-distributedarrays/6651)
**Author:** [@rveltz](https://discourse.julialang.org/u/rveltz)\ **Replies:** 2\ **Last updated:** [November 11, 2017, 7:08am UTC](https://discourse.julialang.org/t/error-using-sum-in-distributedarrays/6651 "2017-11-11T07:08:38Z")
Hi, I am seeking some advice for using the following (piece) of code on a cluster. It is a simulation of a particular type of neural network with N neurons. When, for the last result of a paper, I do simulation for N=1… --- ## [Variable and Equation scaling in JuMP](https://discourse.julialang.org/t/variable-and-equation-scaling-in-jump/5700)
**Author:** [@Sharabh\_Shukla](https://discourse.julialang.org/u/Sharabh_Shukla)\ **Replies:** 3\ **Last updated:** [November 11, 2017, 2:45am UTC](https://discourse.julialang.org/t/variable-and-equation-scaling-in-jump/5700 "2017-11-11T02:45:25Z")
HI everybody, I am writing a SOCP(Second Order Conic Program) in Julia, moving from GAMS. I was wondering how to get variable scaling in JuMP, I need it since in my model some of the variables and equations are badly sc… --- ## [Parallel for triangular domain](https://discourse.julialang.org/t/parallel-for-triangular-domain/7000)
**Author:** [@TomConlin](https://discourse.julialang.org/u/TomConlin)\ **Replies:** 0\ **Last updated:** [November 10, 2017, 9:21pm UTC](https://discourse.julialang.org/t/parallel-for-triangular-domain/7000 "2017-11-10T21:21:16Z")
Apologies for leading with the wall of text, just feeling chuffed at the moment Background: “all v.s. all” comparing elements in a set against all other elements in the set and computing a “distance” between each pai… --- ## [Construct discrete Bloch sum using GPU](https://discourse.julialang.org/t/construct-discrete-bloch-sum-using-gpu/6993)
**Author:** [@louisponet](https://discourse.julialang.org/u/louisponet)\ **Replies:** 3\ **Last updated:** [November 10, 2017, 6:09pm UTC](https://discourse.julialang.org/t/construct-discrete-bloch-sum-using-gpu/6993 "2017-11-10T18:09:45Z")
I’m taking my first plunge into the world of GPU computing. What I’m trying to do is to construct a bloch sum of a wavefunction which is defined over 3 unit cells. The idea is that for each point in space, I take the ori… --- ## [How can i use more than one processor - or give tasks to each processor](https://discourse.julialang.org/t/how-can-i-use-more-than-one-processor-or-give-tasks-to-each-processor/6935)
**Author:** [@leaoshark](https://discourse.julialang.org/u/leaoshark)\ **Replies:** 9\ **Last updated:** [November 9, 2017, 11:00am UTC](https://discourse.julialang.org/t/how-can-i-use-more-than-one-processor-or-give-tasks-to-each-processor/6935 "2017-11-09T11:00:34Z")
Hello Guys … I am tryng to use parallel computing in julia I have to ideas …one is try to set more processors in julia starting ( i do not know how to do that using ATOM ) . or set a task to each processor … for exa… --- ## [JuMP --\> Cbc infeasibility due to too many (valid) constraints?](https://discourse.julialang.org/t/jump-cbc-infeasibility-due-to-too-many-valid-constraints/6895)
**Author:** [@Rafal\_Machalica](https://discourse.julialang.org/u/Rafal_Machalica)\ **Replies:** 6\ **Last updated:** [November 8, 2017, 7:36pm UTC](https://discourse.julialang.org/t/jump-cbc-infeasibility-due-to-too-many-valid-constraints/6895 "2017-11-08T19:36:46Z")
Hello, I’m solving a numeric crosswords (something like this), and I run into an odd issue. I’m using integer programming and Cbc solver. If I type in all the constraints resulting from the given clues (sums of digits … --- ## [Linking installed BONMIN with Julia](https://discourse.julialang.org/t/linking-installed-bonmin-with-julia/6951)
**Author:** [@Rahul\_Sharma](https://discourse.julialang.org/u/Rahul_Sharma)\ **Replies:** 0\ **Last updated:** [November 8, 2017, 6:16am UTC](https://discourse.julialang.org/t/linking-installed-bonmin-with-julia/6951 "2017-11-08T06:16:47Z")
I have installed BONMIN in my Ubuntu system and I want to link it with JuMP. (I have JuliaPro installed) Is there a way to do that? I don’t want to run the command Pkg.add(“CoinOptServices”) due to some reasons. Thanks … --- ## [Simplex tableau](https://discourse.julialang.org/t/simplex-tableau/6652)
**Author:** [@razieh95](https://discourse.julialang.org/u/razieh95)\ **Replies:** 1\ **Last updated:** [November 7, 2017, 8:56pm UTC](https://discourse.julialang.org/t/simplex-tableau/6652 "2017-11-07T20:56:11Z")
Hi my freinds. how to get simplex table in julia? Thanks for your guidance --- ## [MXNet installation fails](https://discourse.julialang.org/t/mxnet-installation-fails/6920)
**Author:** [@v-i-s-h](https://discourse.julialang.org/u/v-i-s-h)\ **Replies:** 1\ **Last updated:** [November 6, 2017, 11:33pm UTC](https://discourse.julialang.org/t/mxnet-installation-fails/6920 "2017-11-06T23:33:23Z")
My attempt to install MXNet fails on Mac OSX 10.13 with the following error. I tried in both Mac OSX 10.13 and Ubuntu 16.04. julia\> versioninfo() Julia Version 0.6.0 Commit 903644385b (2017-06-19 13:05 UTC) Platform Inf… --- ## [Histogram fit error](https://discourse.julialang.org/t/histogram-fit-error/6900)
**Author:** [@SebastianM-C](https://discourse.julialang.org/u/SebastianM-C)\ **Replies:** 3\ **Last updated:** [November 6, 2017, 1:34pm UTC](https://discourse.julialang.org/t/histogram-fit-error/6900 "2017-11-06T13:34:58Z")
Hello, I sometimes get an InexactError() when using fit(Histogram, data, ws, 0:0.25:4, closed=:left). The issue is very strange because it doesn’t always happen. The same code sometimes runs fine, but sometimes I get … --- ## [How to register functions from an array in JuMP?](https://discourse.julialang.org/t/how-to-register-functions-from-an-array-in-jump/6884)
**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\ **Replies:** 3\ **Last updated:** [November 5, 2017, 8:28pm UTC](https://discourse.julialang.org/t/how-to-register-functions-from-an-array-in-jump/6884 "2017-11-05T20:28:22Z")
The signature to register a function in JuMP is as follows JuMP.register(m::Model, s::Symbol, dimension::Integer, f::Function, ∇f::Function, ∇²f::Function) I have an array of unnamed functions, like: funs = \[x -\> x^2,… --- ## [Branch and Bound](https://discourse.julialang.org/t/branch-and-bound/6860)
**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\ **Replies:** 1\ **Last updated:** [November 3, 2017, 9:42pm UTC](https://discourse.julialang.org/t/branch-and-bound/6860 "2017-11-03T21:42:39Z")
I’m a beginner in parallel computing and would like to get some ideas. My project is branch and bound and I’m wondering what the best parallel computing structure is. I have list of open branch nodes. What is the best … --- ## [Using optim.jl ( optimization ) - like fminsearch in matlab](https://discourse.julialang.org/t/using-optim-jl-optimization-like-fminsearch-in-matlab/6709)
**Author:** [@leaoshark](https://discourse.julialang.org/u/leaoshark)\ **Replies:** 48\ **Last updated:** [November 2, 2017, 8:48pm UTC](https://discourse.julialang.org/t/using-optim-jl-optimization-like-fminsearch-in-matlab/6709 "2017-11-02T20:48:24Z")
Hello … it is possible to use optim to solve this ? R = \[0.5 1 2 3\] # so for each R I have one S S = \[1 2 3 4 \] SS(R) = quadgk(a-\> R\*(a^2) \* x\[1\] + R\*\*a\* x\[2\] ,0,Inf) for which x\[1\] and x\[2\] i have SS = S ???… --- ## [Setting dual initial point for warm start](https://discourse.julialang.org/t/setting-dual-initial-point-for-warm-start/6828)
**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\ **Replies:** 2\ **Last updated:** [November 1, 2017, 9:48pm UTC](https://discourse.julialang.org/t/setting-dual-initial-point-for-warm-start/6828 "2017-11-01T21:48:34Z")
Is there a way to set a dual initial point for warm starting? I would like to use it in branch and bound using Ipopt (or any other nlp solver) in the backend for relaxation. Only warm starting on the primal point by set… --- ## [Use Sign function in JuMP](https://discourse.julialang.org/t/use-sign-function-in-jump/6764)
**Author:** [@Qifeng](https://discourse.julialang.org/u/Qifeng)\ **Replies:** 2\ **Last updated:** [October 31, 2017, 8:22pm UTC](https://discourse.julialang.org/t/use-sign-function-in-jump/6764 "2017-10-31T20:22:15Z")
Dear all, I’m solving a MINLP problem in JuMP which contains a nonlinear constraint like this: y = x^2\*sign(x) #both x and y are continuous. Previously, I used Couenne through AmplNLWriter interface and got an error… --- ## [Scientic rounding functions?](https://discourse.julialang.org/t/scientic-rounding-functions/6766)
**Author:** [@John\_Hearns](https://discourse.julialang.org/u/John_Hearns)\ **Replies:** 4\ **Last updated:** [October 30, 2017, 1:17pm UTC](https://discourse.julialang.org/t/scientic-rounding-functions/6766 "2017-10-30T13:17:00Z")
Is there an equivalent of Perl Math::Round package in Julia? Math::Round - Perl extension for rounding numbers - metacpan.org I have found this very useful in the past, the package properly rounds off floating point nu… --- ## [Interpolation with given values and gradients](https://discourse.julialang.org/t/interpolation-with-given-values-and-gradients/6654)
**Author:** [@pablosanjose](https://discourse.julialang.org/u/pablosanjose)\ **Replies:** 10\ **Last updated:** [October 30, 2017, 10:12am UTC](https://discourse.julialang.org/t/interpolation-with-given-values-and-gradients/6654 "2017-10-30T10:12:58Z")
I need to build an interpolation on a function that is known on a grid. Interpolations.jl seems like the perfect package for this. I have two questions, however: 1- I know both the value of the function and its gradient… --- ## [How to replace the current plot in the same browser tab?](https://discourse.julialang.org/t/how-to-replace-the-current-plot-in-the-same-browser-tab/6757)
**Author:** [@turtle](https://discourse.julialang.org/u/turtle)\ **Replies:** 2\ **Last updated:** [October 30, 2017, 9:02am UTC](https://discourse.julialang.org/t/how-to-replace-the-current-plot-in-the-same-browser-tab/6757 "2017-10-30T09:02:17Z")
With Plots + Plotly each new plot is created in a new browser tab. Is it possible to replace the current plot in the same tab? --- ## [How to get @NLparameter in a model?](https://discourse.julialang.org/t/how-to-get-nlparameter-in-a-model/6750)
**Author:** [@CanLi1](https://discourse.julialang.org/u/CanLi1)\ **Replies:** 3\ **Last updated:** [October 30, 2017, 2:38am UTC](https://discourse.julialang.org/t/how-to-get-nlparameter-in-a-model/6750 "2017-10-30T02:38:54Z")
For variables and constraints, we can use the function getindex(m, :x) to get the variable or constraints. But for @NLparameter defined in a model, getindex doesn’t work for me. Does anyone know how to get the NLparamet… --- ## [Using julia vector in R without copying with RCall](https://discourse.julialang.org/t/using-julia-vector-in-r-without-copying-with-rcall/6590)
**Author:** [@vipstar](https://discourse.julialang.org/u/vipstar)\ **Replies:** 2\ **Last updated:** [October 29, 2017, 10:57pm UTC](https://discourse.julialang.org/t/using-julia-vector-in-r-without-copying-with-rcall/6590 "2017-10-29T22:57:04Z")
Hi, I can move an array from R to julia without copying the array (with reval) but I was wondering if there is a way to move a julia vector to R without copying the array using RCall. I want to move the vector into a da… --- ## [Callback function for Fminbox](https://discourse.julialang.org/t/callback-function-for-fminbox/6743)
**Author:** [@depasquale](https://discourse.julialang.org/u/depasquale)\ **Replies:** 0\ **Last updated:** [October 28, 2017, 3:47pm UTC](https://discourse.julialang.org/t/callback-function-for-fminbox/6743 "2017-10-28T15:47:20Z")
I am trying to perform a constrained optimization using fminbox in the optim.jl package and would like to execute a callback function within the inner loop AND the outer loop to terminate the optimization if too much tim… [Previous page](https://discourse.julialang.org/c/domain/10.md?page=549) [Next page](https://discourse.julialang.org/c/domain/10.md?page=551)