Regarding plotting of graphs, Gnuplot gives better results than spreadsheet.
A few years ago I revived a utilty named Jiff which was originally written by G Agostino and distributed with JSBSim. I hacked it so that it would find and plot all tables in my JSBSim fdm. The original only handled files which are close to the Aeromatic format and did not cope with some more JSBSim constructions.
Jiff takes as its input the xml FDM file, and produces data files which it sends to Gnuplot. (Gnuplot needs to be installed. ) I use Windows, but there is no reason why it should not work on any platform (e.g. Linux, Mac) that can run Gnuplot .
Please feel free to hack it further if it does not handle your own FDM, or you wish to improve it. I have left plenty of scope for this
The git repo is at
https://github.com/alanjt/Jiff.
It should be failrly self explanatory if you read the code.
One important constraint is that each table needs to have a <table name= "abcdef> definition, as this name is used to form the Gnuplot filenames.
e.g.
<function name="aero/coefficient/FlapBlowCoeffLimit">
<description>Flap Blowing Coefficient Limits</description>
<table name = "TableFlapBlowCoeffLim">
<independentVar lookup = "row">fcs/flap-pos-deg</independentVar>
<tableData>
15 0.0
20 0.0034
35 0.0088
50 0.015
</tableData>
</table>
</function>
Alan