# Set different tolerances for each variable when using ODE solvers

**URL:** <https://discourse.julialang.org/t/set-different-tolerances-for-each-variable-when-using-ode-solvers/76861>\
**Category:** General Usage\
**Created:** [February 21, 2022, 7:39pm UTC](https://discourse.julialang.org/t/set-different-tolerances-for-each-variable-when-using-ode-solvers/76861 "2022-02-21T19:39:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Yinmin\_Liu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yinmin_liu/32/31880_2.png) [@Yinmin\_Liu](https://discourse.julialang.org/u/Yinmin_Liu)\
**Post date:** [February 21, 2022, 7:39pm UTC](https://discourse.julialang.org/t/set-different-tolerances-for-each-variable-when-using-ode-solvers/76861/1 "2022-02-21T19:39:22Z")

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I am trying to solve two coupled ODE systems together. In Python ODE solvers (SciPy), I can pass a list of tolerance values for each variable. How can I do the same thing in Julia solvers?

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**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:** [February 22, 2022, 1:37am UTC](https://discourse.julialang.org/t/set-different-tolerances-for-each-variable-when-using-ode-solvers/76861/2 "2022-02-22T01:37:28Z")

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Yes, just pass an array of tolerances.

[https://diffeq.sciml.ai/stable/basics/common\_solver\_opts/#Basic-Stepsize-Control](https://diffeq.sciml.ai/stable/basics/common_solver_opts/#Basic-Stepsize-Control)

> Note tolerances can be specified element-wise by passing a vector whose size matches `u0` .

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**Author:** ![photor](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/photor/32/14343_2.png) [@photor](https://discourse.julialang.org/u/photor)\
**Post date:** [February 22, 2022, 6:27am UTC](https://discourse.julialang.org/t/set-different-tolerances-for-each-variable-when-using-ode-solvers/76861/3 "2022-02-22T06:27:33Z")

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It’s so helpful. Thanks.