# Numerical differentiation with bump size

**URL:** <https://discourse.julialang.org/t/numerical-differentiation-with-bump-size/78254>\
**Category:** General Usage\
**Tags:** differentiation, finitediff\
**Created:** [March 22, 2022, 6:14am UTC](https://discourse.julialang.org/t/numerical-differentiation-with-bump-size/78254 "2022-03-22T06:14:25Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Lincoln\_Hannah](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/lincoln_hannah/32/19198_2.png) [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Post date:** [March 22, 2022, 6:14am UTC](https://discourse.julialang.org/t/numerical-differentiation-with-bump-size/78254/1 "2022-03-22T06:14:25Z")

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Is there a numerical differentiation package that allows you to specify the size of the bump ?

I’d like to do f(x + d) - f(x) and specify the d (e.g. 0.001)

FiniteDifferences seems to focus on approximating the actual derivative.

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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:** [March 22, 2022, 7:51am UTC](https://discourse.julialang.org/t/numerical-differentiation-with-bump-size/78254/2 "2022-03-22T07:51:53Z")

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You can set the stepsize in FiniteDiff.jl

[https://github.com/JuliaDiff/FiniteDiff.jl/blob/master/src/jacobians.jl#L160-L161](https://github.com/JuliaDiff/FiniteDiff.jl/blob/master/src/jacobians.jl#L160-L161)

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<div class="post-metadata">

**Author:** ![Lincoln\_Hannah](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/lincoln_hannah/32/19198_2.png) [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Post date:** [March 22, 2022, 9:30am UTC](https://discourse.julialang.org/t/numerical-differentiation-with-bump-size/78254/3 "2022-03-22T09:30:16Z")

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Many thanks