.. Perun PowerDesk Documentation
   file: dst_statsigmap.rst
   Copyright (c) 2016
   Perun Technologies

.. _staticSignalMapping:

Adding Static Signal Mappings
=============================

A *static* signal mapping is a point-wise transformation of one signal into another. This is a mapping in which every signal sample is transformed independently of other samples. Oposite kind of signal transformations are dynamic transforms, including **filtering** (see :ref:`filteredSignal`), where each sample is mapped taking in consideration values of its neighbouring samples.

Some well-known and widely used examples of static or point-wise mappings are:

* **scaling** : multiplication of signals with a constant
* **value shift** or **offset** : adding a constant to a signal
* various nonlinear transforms, including finding **square roots** or **powers** of signal values.

Note also that any combination of pint-wise mapping is itslef a pointwise transform.

To create a static signal map in ``Perun PowerDesk``, simply choose **Add Static Signal Mapping ...** option from the Main Window Ribbon Menu. The following dialog appears

.. figure:: _static/images/dst_staticmap.png
  :figwidth: 70%
  :align: center

  The **Define Static Signal Map** dialog.

The dialog allows for defining the **source signal**, i.e. the signal to be mapped, the **name of the transformed signal**, and the **expression** used to transform the source signal. The expression uses symbol ``x`` to denote the value of the source sample. Otherwise, the syntax is common and straightforward to use. For more details see :ref:`expressionSyntax`.