.. _method-multilevel_polynomial_chaos-export_expansion_file: """"""""""""""""""""" export_expansion_file """"""""""""""""""""" Export the coefficients and multi-index of a Polynomial Chaos Expansion (PCE) to a file .. toctree:: :hidden: :maxdepth: 1 **Specification** - *Alias:* None - *Arguments:* STRING **Description** Export the coefficients and multi-index of a Polynomial Chaos Expansion (PCE) to a file. The multi-index written will be sparse. Spcifically the expansion will conists only of the indices corresponding to the non-zero coefficients of the PCE.