# Dirac Delta Function with Discontinuous Lagrange

**URL:** <https://fenicsproject.discourse.group/t/dirac-delta-function-with-discontinuous-lagrange/9355>\
**Category:** dolfinx\
**Created:** [September 23, 2022, 10:15pm UTC](https://fenicsproject.discourse.group/t/dirac-delta-function-with-discontinuous-lagrange/9355 "2022-09-23T22:15:02Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![MattMcLean](https://avatars.discourse-cdn.com/v4/letter/m/838e76/32.png) [@MattMcLean](https://fenicsproject.discourse.group/u/MattMcLean)\
**Post date:** [September 23, 2022, 10:15pm UTC](https://fenicsproject.discourse.group/t/dirac-delta-function-with-discontinuous-lagrange/9355/1 "2022-09-23T22:15:02Z")

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Hi all,

I have successfully implemented interior nodal sources within dolfinx and “CG” elements. However, when I switch to “DG” elements, then this does not work. Does anyone know if you can add an interior source at a point with “DG” elements.

Thanks!