Spectrum 2D
*********************

The widget allows the user to plot multiple spectrum attributes on the y-axis against a single spectrum attribute on the x-axis. This one-to-many configuration lets users specify one spectrum attribute for the x-axis and several for the y-axis.
The ``Time Base`` is used as the spectrum attribute for the x-axis of the oscilloscope. Since the widget supports multiple y-axis spectrum attributes, clicking the "+" sign next to ``Graphs`` allows the user to add another spectrum attribute and choose a line color for it.

Widget setting 
==============

The following image shows an example of a widget setting.

\ |IMG1|\

It is possible to customize the widget settings from the inspector panel (in edit mode), as shown below: 

+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Input value                |Description                                                                                                                                  |
+===========================+=============================================================================================================================================+
|Device                     |Type in a device name (or * to list all)                                                                                                     |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Attribute                  |Once a device is selected, type in an attribute name (or * to list all available attributes)                                                 |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Graphs                     |Opens the configuration for individual plots (see below)                                                                                     |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Attribute Display          |Select the Label, Name, or None for the attribute                                                                                            |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Show Title                 |Displays the title when enabled                                                                                                              |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Show Tango Database Name   |Displays the tango database name when enabled                                                                                                |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|X-axis Scientific Notation |Enable this option to display the X-axis values in scientific notation                                                                       |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Y-axis Scientific Notation |Enable this option to display the Y-axis values in scientific notation                                                                       |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|X-axis Logarithmic Scale   |Enable to apply a logarithmic scale to the X-axis                                                                                            |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Y-axis Logarithmic Scale   |Enable to apply a logarithmic scale to the Y-axis                                                                                            |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Plot Styling               |The option of adjusting the style of plot indicators                                                                                         |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Text Color                 |Specify the text color for the given widget                                                                                                  |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+
|Background Color           |Specify the background color for the given widget                                                                                            |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------+

Graph configuration
===================

When clicking on the ``Graphs`` option, a new plot can be configured with the following settings:

+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|Input value                    |Description                                                                                                                                                            |
+===============================+=======================================================================================================================================================================+
|Device                         |Type in a device name (or * to list all)                                                                                                                               |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|Attribute                      |Once a device is selected, type in an attribute name (or * to list all available attributes)                                                                           |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|Line Color                     |Specify the line color for the given widget                                                                                                                            |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+

*The y-axis contains four spectrum attributes representing four dictinct channels and their waveform voltages from an ossiloscope plotted against another spectrum attribute called time-range*

\ |IMG2|  |IMG3| \

*The y-axis, plotted against the spectrum attribute called `float_spectrum_ro`, contains:*  

* *two spectrum attributes, `float_spectrum_ro` and `double_spectrum_ro`, are drawn on a Bar Chart plot using scientific notation format and a logarithmic scale on the y-axis (left),*  
* *one spcetrum attribute, `float_spectrum_ro`, is drawn on a Marker plot (right).*  

Widget design
==============
The plot is rendered using plotly, a robust and interactive graphing library. The plots are re-drawn as they are updated with spectrum attribute data pushed by the respective tango device to which the attributes are associate. Plotly natively provides a couple of tools for interacting with the plots, including zooming, panning, focusing on specific graph parts, resetting axes and saving snapshots of the graph as Portable Network Graphics(PNG) files. 


\ |IMG4|\ 

*The plot shown above is a sample of a four channel oscilloscope plotted against (psuedo) time-range*

\ |IMG5|\ 

*The plots above, plotted against `float_spectrum_ro`, shows:*

* *spectrum attributes `float_spectrum_ro` with `double_spectrum_ro` drawn on a Bar Chart plot with scientific notation format and logarithmic scale on y-axis  (left),*  
* *spectrum attributes `float_spectrum_ro` drawn on a Marker plot with linear scale on both axes (right)*  

.. bottom of content

.. |IMG1| image:: _static/img/spectrum_2d_settings.png

.. |IMG2| image:: _static/img/spectrum_2d_settings1.png

.. |IMG3| image:: _static/img/spectrum_2d_settings2.png

.. |IMG4| image:: _static/img/spectrum_2d_design.png

.. |IMG5| image:: _static/img/spectrum_2d_plots.png