.. _profile_smoothing:

Profile smoothing
=================

Profile smoothing may be applied to profiles in the Spatial Profiler Widget, the Spectral Profiler Widget, and the Stokes Analysis Widget to enhance the signal-to-noise ratio. You can access the settings from the "**Smoothing**" tab of the settings dialogs of these widgets. 

.. raw:: html

   <a href="_static/carta_fn_profileSmoothing.png" target="_blank">
       <img src="_static/carta_fn_profileSmoothing.png" 
           style="width:100%;height:auto;">
   </a>

Optionally, the original profile can be overplotted with the smoothed profile. The appearance of the smoothed profile, including color, style, width, and size, can be customized.

Smoothing methods
-----------------

CARTA provides the following smoothing methods:

* Boxcar: convolution with a boxcar function
* Gaussian: convolution with a Gaussian function
* Hanning: convolution with a Hanning function
* Binning: averaging channels with a given width
* Savitzky-Golay: fitting successive sub-sets of adjacent data points with a low-degree polynomial by the method of linear least squares
* Decimation: min-max decimation with a given width    

.. raw:: html

   <a href="_static/carta_fn_profileSmoothing_examples.png" target="_blank">
       <img src="_static/carta_fn_profileSmoothing_examples.png" 
           style="width:100%;height:auto;">
   </a>