# Material derivative

**URL:** <https://community.freefem.org/t/material-derivative/1179>\
**Category:** General Discussion\
**Created:** [August 27, 2021, 7:40am UTC](https://community.freefem.org/t/material-derivative/1179 "2021-08-27T07:40:34Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![xiaojiemo](https://avatars.discourse-cdn.com/v4/letter/x/a4c791/32.png) [@xiaojiemo](https://community.freefem.org/u/xiaojiemo)\
**Post date:** [August 27, 2021, 7:40am UTC](https://community.freefem.org/t/material-derivative/1179/1 "2021-08-27T07:40:34Z")

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Dear FreeFEM users,  
I would like to ask a question about material derivative, whose form is D(X)=dx/dt+vx\*gradx. how to define it ?