# Knowing what package a function is from?

**URL:** <https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258>\
**Category:** General Usage\
**Tags:** package\
**Created:** [October 29, 2020, 7:35pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258 "2020-10-29T19:35:26Z")\
**Posts on this page:** 19\
**Page:** 2

<div class="post-metadata">

**Author:** ![BLI](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/bli/32/37206_2.png) [@BLI](https://discourse.julialang.org/u/BLI)\
**Post date:** [October 31, 2020, 12:56pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/21 "2020-10-31T12:56:56Z")

</div>

> [@ChrisRackauckas](#):
>
> Yes: ModelingToolkit is built with SymbolicUtils as its utility backend. But ModelingToolkit is a full complete CAS.

Are there plans to include integration in ModelingToolkit?

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [October 31, 2020, 5:31pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/22 "2020-10-31T17:31:45Z")

</div>

> [@BLI](#):
>
> Are there plans to include integration in ModelingToolkit?

Yes, we have a student working on this right now. Don’t expect it too soon though.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [October 31, 2020, 7:14pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/23 "2020-10-31T19:14:35Z")

</div>

Agree fully. A CAS is useful in research, and a CAS for undergrads as an open source alternative to Maple or Mathematica, but also as a way to introduce Julia programming at the undergrad and high school student.

Odly enough when I was reading the word docs I thought you said .docx, and I was thinking a Word add in notebook (a sort of Jupyter, or Pluto style notebook), would be really cool. There’s already the JuliaPro add in for Excel, and the combinitation of the 3 could do a lot of algebra, calculus and stats work.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 4:14am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/24 "2020-11-01T04:14:55Z")

</div>

How do I simplify a function in ModelToolkit? I’ve figured out how to do most things in SymEngine, but I can’t find a simplify command. (As of 2017 there wasn’t one). If I completely switch over, how do I do differentials and limits?

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 1, 2020, 4:17am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/25 "2020-11-01T04:17:18Z")

</div>

`simplify`.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 4:22am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/26 "2020-11-01T04:22:29Z")

</div>

Makes sense, but I can’t install ModelingToolkit I typed the name directly but instead get

```julia
Error Unjustifiable requirements detected for package ModelingToolkit [961ee093]
```

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 1, 2020, 6:06am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/27 "2020-11-01T06:06:58Z")

</div>

You have to share the error message.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 6:30am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/28 "2020-11-01T06:30:16Z")

</div>

Sorry, I shared the first line. I can’t copy from the REPL in VS Code with a mouse, for some reason. But, I should use keyboard keys more for that.

```julia
julia> Pkg.add("ModelingToolkit")
 Resolving package versions...
ERROR: Unsatisfiable requirements detected for package ModelingToolkit [961ee093]:
 ModelingToolkit [961ee093] log:
 ├─possible versions are: [0.0.1-0.0.2, 0.1.0, 0.2.0, 0.4.0, 0.5.0, 0.6.0-0.6.1, 0.6.3-0.6.4, 0.7.0-0.7.2, 0.8.0, 0.9.0-0.9.1, 0.10.0, 1.0.0-1.0.3, 1.1.0-1.1.3, 1.2.0-1.2.10, 1.3.0-1.3.3, 1.4.0-1.4.3, 2.0.0, 3.0.0-3.0.2, 3.1.0-3.1.1, 3.2.0, 3.3.0, 3.4.0, 3.5.0, 3.6.0-3.6.4, 3.7.0-3.7.1, 3.8.0, 3.9.0, 3.10.0-3.10.2, 3.11.0-3.11.1, 3.12.0-3.12.2, 3.13.0, 3.14.0-3.14.2, 3.15.0, 3.16.0, 3.17.0, 3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0] or uninstalled   
 ├─restricted to versions * by an explicit requirement, leaving only versions [0.0.1-0.0.2, 0.1.0, 0.2.0, 0.4.0, 0.5.0, 0.6.0-0.6.1, 0.6.3-0.6.4, 0.7.0-0.7.2, 0.8.0, 0.9.0-0.9.1, 0.10.0, 1.0.0-1.0.3, 1.1.0-1.1.3, 1.2.0-1.2.10, 1.3.0-1.3.3, 1.4.0-1.4.3, 2.0.0, 3.0.0-3.0.2, 3.1.0-3.1.1, 3.2.0, 3.3.0, 
3.4.0, 3.5.0, 3.6.0-3.6.4, 3.7.0-3.7.1, 3.8.0, 3.9.0, 3.10.0-3.10.2, 3.11.0-3.11.1, 3.12.0-3.12.2, 3.13.0, 3.14.0-3.14.2, 3.15.0, 3.16.0, 3.17.0, 3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0]
 ├─restricted by compatibility requirements with Latexify [23fbe1c1] to versions: [0.0.1-0.0.2, 0.1.0, 0.2.0, 0.4.0, 0.5.0, 0.6.0-0.6.1, 0.6.3-0.6.4, 
0.7.0-0.7.2, 0.8.0, 3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0] or uninstalled, 
leaving only versions: [0.0.1-0.0.2, 0.1.0, 0.2.0, 0.4.0, 0.5.0, 0.6.0-0.6.1, 0.6.3-0.6.4, 0.7.0-0.7.2, 0.8.0, 3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0] 
 │ └─Latexify [23fbe1c1] log:
 │ ├─possible versions are: [0.5.0-0.5.1, 0.6.0, 0.7.0, 0.8.1-0.8.2, 0.9.0, 0.10.0, 0.11.0, 0.12.0-0.12.3, 0.13.0-0.13.5, 0.14.0-0.14.1] or uninstalled
 │ └─restricted to versions 0.14.1 by an explicit requirement, leaving only versions 0.14.1
 ├─restricted by compatibility requirements with SpecialFunctions [276daf66] to versions: [1.1.3, 1.2.0-1.2.10, 1.3.0-1.3.3, 1.4.0-1.4.3, 2.0.0, 3.0.0-3.0.2, 3.1.0-3.1.1, 3.2.0, 3.3.0, 3.4.0, 3.5.0, 3.6.0-3.6.4, 3.7.0-3.7.1, 
3.8.0, 3.9.0, 3.10.0-3.10.2, 3.11.0-3.11.1, 3.12.0-3.12.2, 3.13.0, 3.14.0-3.14.2, 3.15.0, 3.16.0, 3.17.0, 3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0] or uninstalled, leaving only versions: [3.18.0, 3.19.0, 3.20.0-3.20.1, 3.21.0]  
 │ └─SpecialFunctions [276daf66] log:
 │ ├─possible versions are: [0.7.0-0.7.2, 0.8.0, 0.9.0, 0.10.0-0.10.3] or uninstalled
 │ └─restricted to versions 0.10.0 by an explicit requirement, leaving only versions 0.10.0
 └─restricted by compatibility requirements with SymbolicUtils [d1185830] to versions: [0.0.1-0.0.2, 0.1.0, 0.2.0, 0.4.0, 0.5.0, 0.6.0-0.6.1, 0.6.3-0.6.4, 0.7.0-0.7.2, 0.8.0, 0.9.0-0.9.1, 0.10.0, 1.0.0-1.0.3, 1.1.0-1.1.3, 1.2.0-1.2.10, 1.3.0-1.3.3, 1.4.0-1.4.3, 2.0.0, 3.0.0-3.0.2, 3.1.0-3.1.1] or uninstalled — no versions left
   └─SymbolicUtils [d1185830] log:
     ├─possible versions are: [0.1.0-0.1.2, 0.2.0-0.2.1, 0.3.0-0.3.4, 0.4.0-0.4.3, 0.5.0-0.5.2, 0.6.0] or uninstalled
     └─restricted to versions 0.6.0 by an explicit requirement, leaving only versions 0.6.0
Stacktrace:
 [1] #propagate_constraints!#61(::Bool, ::typeof(Pkg.GraphType.propagate_constraints!), ::Pkg.GraphType.Graph, ::Set{Int64}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\GraphType.jl:1007     
 [2] propagate_constraints! at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\GraphType.jl:948 [inlined]
 [3] #simplify_graph!#121(::Bool, ::typeof(Pkg.GraphType.simplify_graph!), 
::Pkg.GraphType.Graph, ::Set{Int64}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\GraphType.jl:1462
 [4] simplify_graph! at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\GraphType.jl:1462 [inlined] (repeats 2 times)      
 [5] resolve_versions!(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\Operations.jl:321
 [6] #add#112(::Bool, ::Pkg.BinaryPlatforms.Windows, ::typeof(Pkg.Operations.add), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}, ::Array{Base.UUID,1}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\Operations.jl:1010
 [7] #add at .\none:0 [inlined]
 [8] #add#25(::Bool, ::Pkg.BinaryPlatforms.Windows, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.add), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:102
 [9] add(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:72
 [10] #add#24 at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:69 [inlined]
 [11] add at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:69 [inlined]
 [12] #add#21 at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:67 [inlined]
 [13] add at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:67 [inlined]
 [14] #add#20(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.add), ::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:66
 [15] add(::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:66
 [16] top-level scope at REPL[640]:1

```

oddly enough, I was able to load NLsolve and SymUtils, so I was able to do all the differentiation I was doing in SymEngine, and the simplificiation from SymUtils.

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 1, 2020, 6:45am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/29 "2020-11-01T06:45:54Z")

</div>

Try `up` before you install again?

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 6:46am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/30 "2020-11-01T06:46:19Z")

</div>

up?

---

<div class="post-metadata">

**Author:** ![Skoffer](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/skoffer/32/378_2.png) [@Skoffer](https://discourse.julialang.org/u/Skoffer)\
**Post date:** [November 1, 2020, 6:55am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/31 "2020-11-01T06:55:45Z")

</div>

`up` from `update`. This command update all packages [Pkg · The Julia Language](https://docs.julialang.org/en/v1/stdlib/Pkg/)

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 7:05am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/32 "2020-11-01T07:05:57Z")

</div>

I just updated it, and I still get the same error.

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 1, 2020, 10:59am UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/33 "2020-11-01T10:59:53Z")

</div>

What if you do `]add ModelingToolkit@4`?

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 6:58pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/34 "2020-11-01T18:58:14Z")

</div>

Same error.

---

<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 1, 2020, 7:50pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/35 "2020-11-01T19:50:56Z")

</div>

Everything exactly the same? This is standard open source Julia v1.5?

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 1, 2020, 8:11pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/36 "2020-11-01T20:11:41Z")

</div>

My bad, I’m on v1.3 I can’t remember how to update (I was away on other stuff over the last year).

---

<div class="post-metadata">

**Author:** ![josePereiro](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/josepereiro/32/17322_2.png) [@josePereiro](https://discourse.julialang.org/u/josePereiro)\
**Post date:** [November 1, 2020, 11:53pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/37 "2020-11-01T23:53:30Z")

</div>

You can use a fresh new [enviroment](https://julialang.github.io/Pkg.jl/v1.1/environments/) for testing. You are having some dependency troubles in the environment you are using now. Also, if you don’t mind this environment to much you can restart it by deleting its Project.toml and add packages again. On other hands, that will be a good Pkg practice section.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 4, 2020, 4:29pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/38 "2020-11-04T16:29:36Z")

</div>

I might want to learn that, currently I like the way that ModelingToolkit writes derivatives, but it doesn’t do a good job of simplifying, while SymPy does do a good job of simplifying.

---

<div class="post-metadata">

**Author:** ![brett\_knoss](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/brett_knoss/32/13050_2.png) [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Post date:** [November 10, 2020, 9:03pm UTC](https://discourse.julialang.org/t/knowing-what-package-a-function-is-from/49258/39 "2020-11-10T21:03:21Z")

</div>

Ok, thanks good to know.

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