.. highlightlang:: us

.. _sgolayfilt:

sgolayfilt
==========

.. index:: smooth

.. index:: Glätten

.. index:: Golay

.. index:: Savitzky-Golay

.. index:: sgolayfilt

.. us.tag  sgolayfilt ENGLISH Interpolation New580

:ref:`sgolayfilt` computes a moving average using the Savitzky-Golay algorithm.

.. function::  rvY2 = sgolayfilt(rvY1)
    rvY2 = sgolayfilt(rvY1, p)
    rvY2 = sgolayfilt(rvY1, p, nNeighbor)

.. us.return

**Return Value**

The return value *rvY2* is a real vector.

.. us.params

**Parameters**

.. uparam:: rvY1

   *rvX* is a real vector with at least *p* elements.

.. uparam:: p

   Order of polynom (1 to 10, default = 3). 

.. uparam:: nNeighbor

   *nNeighbor* specifies the window width. The window width is 
   ``2 * nNeighbor + 1``. Default value = 20.

.. us.example

**Example**

.. image:: S:/uniplot-obj/images/savitzky-golay.*

::

   def test_sgolay()
   {
       N = 200;
       t = linspace(0, 10, N);
       s = sin(2*PI/5*t);
       srand(1);
       sr = s + 0.3 * (rand(size(t))-0.5);
       // Sinus
       h = plot(t, s);
       XYSetProps(h[3], "curve-color='black'")
       XYSetLegendText(h[3], "sinus");
       // sin+rand
       h = plot(t, sr,  h[2]);
       XYSetProps(h[3], "curve-color='blue'")
       XYSetLegendText(h[3], "sinus+random");
       y = moving_average(sr, 10)
       h = plot(t, y,  h[2]);
       XYSetProps(h[3], "curve-color='red'")
       XYSetLegendText(h[3], "moving average (smooth())");
       // smooth(sin+rand)
       y = sgolayfilt(sr, 3, 20);
       h = plot(t, y, h[2]);
       XYSetProps(h[3], "curve-color='green'")
       XYSetLegendText(h[3], "Savitzky-Golay Filter");
   }

.. us.history

**History**

.. list-table::
   :header-rows: 1

   * - Version
     - Description
   * - 5.8.0
     - New

.. seealso::
   :ref:`overview-mathematic`,
   :ref:`pspline`,
   :ref:`fspline`,
   :ref:`akimaspline`,
   :ref:`interpol`,
   :ref:`moving_average`

:sub:`id-931091`