# Finding the coefficient in an expression in Symbolics.jl

**URL:** <https://discourse.julialang.org/t/finding-the-coefficient-in-an-expression-in-symbolics-jl/67424>\
**Category:** General Usage\
**Tags:** symbolics\
**Created:** [August 31, 2021, 12:57pm UTC](https://discourse.julialang.org/t/finding-the-coefficient-in-an-expression-in-symbolics-jl/67424 "2021-08-31T12:57:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![fgerick](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fgerick/32/13228_2.png) [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Post date:** [August 31, 2021, 12:57pm UTC](https://discourse.julialang.org/t/finding-the-coefficient-in-an-expression-in-symbolics-jl/67424/1 "2021-08-31T12:57:23Z")

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Is there already something like the `coeff` function of SymPy for Symbolics.jl? E.g. in SymPy I do

```julia
using SymPy
@syms x y f()
ex = x^2*diff(f(x,y),y) + y^2
ex.coeff(diff(f(x,y),y))
# x^2

```

Can I do the same using Symbolics/ModelingToolkit ?

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<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:** [September 10, 2021, 9:57am UTC](https://discourse.julialang.org/t/finding-the-coefficient-in-an-expression-in-symbolics-jl/67424/2 "2021-09-10T09:57:26Z")

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Open an issue. I don’t think we have a generic function for this.

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<div class="post-metadata">

**Author:** ![fgerick](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fgerick/32/13228_2.png) [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Post date:** [September 10, 2021, 12:44pm UTC](https://discourse.julialang.org/t/finding-the-coefficient-in-an-expression-in-symbolics-jl/67424/3 "2021-09-10T12:44:59Z")

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[https://github.com/JuliaSymbolics/Symbolics.jl/issues/374](https://github.com/JuliaSymbolics/Symbolics.jl/issues/374)