# Numeric/Symbolic derivatives

**URL:** https://forum.dynare.org/t/numeric-symbolic-derivatives/13624
**Category:** Dynare++
**Created:** [13 April 2019 11:15 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624 "2019-04-13T11:15:05Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![CZJAN](https://forum.dynare.org/letter_avatar_proxy/v4/letter/c/a88e4f/32.png) [@CZJAN](https://forum.dynare.org/u/CZJAN)
#### Post date: [13 April 2019 11:15 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/1 "2019-04-13T11:15:05Z")

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Dear Dynare team,

I need to ask whether Dynare++ computes symbolic or numeric derivatives in order to find k-th order perturbation approximation and if it does use symbolic derivatives, it is possible to access them?

Best Regards  
Jan Žemlička

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### Author: ![jpfeifer](https://forum.dynare.org/user_avatar/forum.dynare.org/jpfeifer/32/5044_2.png) [@jpfeifer](https://forum.dynare.org/u/jpfeifer)
#### Post date: [15 April 2019 12:30 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/2 "2019-04-15T12:30:56Z")

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It computes symbolic ones, but they cannot be easily accessed.

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### Author: ![CZJAN](https://forum.dynare.org/letter_avatar_proxy/v4/letter/c/a88e4f/32.png) [@CZJAN](https://forum.dynare.org/u/CZJAN)
#### Post date: [15 April 2019 12:42 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/3 "2019-04-15T12:42:07Z")

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Thank you very much!

Best  
Jan

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### Author: ![sebastien](https://forum.dynare.org/user_avatar/forum.dynare.org/sebastien/32/19973_2.png) [@sebastien](https://forum.dynare.org/u/sebastien)
#### Post date: [29 April 2019 10:19 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/4 "2019-04-29T10:19:04Z")

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@CZJAN Actually, if you install Dynare unstable snapshot, it’s now possible to get the k-th order derivatives in JSON format. For example, if you want order 5, specify `stoch_simul(order=5, irf=0);` in the mod-file, and then run dynare with the `json=compute` option.

The k-th order derivatives will be in the file called: `<model_name>/model/json/dynamic.json` (where `<model_name>` is the filename of your mod-file, without the extension).

Hope this helps

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### Author: ![CZJAN](https://forum.dynare.org/letter_avatar_proxy/v4/letter/c/a88e4f/32.png) [@CZJAN](https://forum.dynare.org/u/CZJAN)
#### Post date: [20 May 2019 22:22 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/5 "2019-05-20T22:22:32Z")

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Dear Sebastien,

thank you very much! Does Dynare snapshot also includes k-level pruning for stochastic simulations/irfs?

Best  
Jan

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### Author: ![jpfeifer](https://forum.dynare.org/user_avatar/forum.dynare.org/jpfeifer/32/5044_2.png) [@jpfeifer](https://forum.dynare.org/u/jpfeifer)
#### Post date: [21 May 2019 06:25 UTC](https://forum.dynare.org/t/numeric-symbolic-derivatives/13624/6 "2019-05-21T06:25:24Z")

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Not yet. See [https://git.dynare.org/Dynare/dynare/issues/1643](https://git.dynare.org/Dynare/dynare/issues/1643)