# Usage of @ode\_def

**URL:** <https://discourse.julialang.org/t/usage-of-ode-def/57613>\
**Category:** New to Julia\
**Created:** [March 20, 2021, 4:47pm UTC](https://discourse.julialang.org/t/usage-of-ode-def/57613 "2021-03-20T16:47:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Manisha\_07](https://avatars.discourse-cdn.com/v4/letter/m/57b2e6/32.png) [@Manisha\_07](https://discourse.julialang.org/u/Manisha_07)\
**Post date:** [March 20, 2021, 4:47pm UTC](https://discourse.julialang.org/t/usage-of-ode-def/57613/1 "2021-03-20T16:47:36Z")

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Hello  
I am trying to use @ode\_def ,but i am getting error msg as “LoadError: UndefVarError: @ode\_def not defined in expression starting at In[1]:1”  
How would I resolve this issue…

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<div class="post-metadata">

**Author:** ![oheil](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oheil/32/220745_2.png) [@oheil](https://discourse.julialang.org/u/oheil)\
**Post date:** [March 20, 2021, 5:32pm UTC](https://discourse.julialang.org/t/usage-of-ode-def/57613/2 "2021-03-20T17:32:31Z")

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Are you starting with:

```julia
using ParameterizedFunctions

```

?

It seems you are in some Jupiter notebook, you may have to run some cell above.  
See [ParameterizedFunctions · DifferentialEquations.jl](https://diffeq.sciml.ai/stable/analysis/parameterized_functions/) for documentation.