  A numerical tool for analysing spatially anisotropic electron populations in
electron cyclotron resonance (ECR) plasmas has been developed, using a
trial-and-error electron energy distribution function (EEDF) fitting method.
The method has been tested on space-resolved warm electrons in the energy range
$2-20\,\mathrm{keV}$, obtained from self-consistent simulations modelling only
electron dynamics in ECR devices, but lacked real-world validation. For
experimentally benchmarking the method, we attempted to numerically reproduce
the experimental X-ray emission spectrum measured from an argon plasma. Results
of this analysis have provided crucial information about density and
temperature of warm electrons, and competing distributions of warm and hot
electron components. This information can be fed back to simulation models to
generate more realistic data. Subsequent application of the numerical tool as
described to the improved simulation data can result in continuous EEDFs that
reflect the nature of charge distributions in anisotropic ECR plasmas. These
functions can be also applied to electron dependent reactions, in order to
reproduce experimental results, like those concerning space-dependent K$\alpha$
emissions.
