A utility function that can easily replace wavenumbers (x)

[markotoplak]

Renames are saved into the domain so that also new data can be transformed in the same way.

This was Feri's idea. He asked how to transform X and I figured it would be, for starter, nice to have a utility function that does that.

[codecov[bot]]

Codecov Report

Merging #678 (cd4cafa) into master (495e880) will increase coverage by 0.00%. The diff coverage is 100.00%.

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##           master     #678   +/-   ##
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  Coverage   89.36%   89.36%           
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  Files          72       72           
  Lines       11994    12000    +6     
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+ Hits        10718    10724    +6     
  Misses       1276     1276           

[borondics]

Seems to work great!

Thanks a lot!!!