Drawing A Plot From The Sweep Data - Mini-Circuits ISC-2425-25+ Quick Start Manual

3.5.2

Drawing a plot from the sweep data

After the sweep has been executed successfully, the data can be used to draw a plot and give the user a more easily
digestible overview than a bunch of text.
This is done in the 'SWP_draw_plot' function.
The SWP_draw_plot function uses the open source QCustomPlot library by Emanuel Eichhammer, available for download
here: https://www.qcustomplot.com/index.php/download
Documentation of the QCustomPlot is available here:
https://www.qcustomplot.com/index.php/tutorials/settingup

https://www.qcustomplot.com/documentation/index.html

First the contents of the sweep QVectors are checked. They mustn't be empty.
Next the X-axis of the plot is configured to display the frequency data saved in the frequency QVector. Additionally,
the Y-axis, which will show S11 data, is configured for 2 decimals of precision.
Now it is time to deal with the S11 data.
Two variables of the type double are prepared, to store the smallest and largest values of the S11 data, to be used later
for setting the range of the Y-axis.
The 'SWP_draw_plot' function takes an 'S11_notation' argument. This argument can be either 'logarithmic' or 'linear', and
the plot is drawn differently depending on the choice.
If the notation is logarithmic, the plot uses data from the 'SWP_s11_dbm_data' QVector.
The smallest and largest values from the QVector are stored in 'min_val' and 'max_val', though they are ignored if
they exceed 0, as an S11 graph is expected to consist of only negative values.
The visible limits of the plot's Y-axis are set to smallest and largest S11 values multiplied by a factor of 1.1 for improved
visibility.
AN-50-008 Rev: OR
This document and its contents are the property of Mini-Circuits.
DCO-000822 (03/07/22) File: AN-50-008.docx
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