This is a program for checking all currently archived PVs, for example, for their values and their
consumed storage on all archiver appliances.


PREREQUISIT
-----------

You need to have at least a java version 1.8 installed. To check this your command-line
output of "java -version" and "javac -version" should yield at least 1.8.* .

COMPILING THE PROJECT
---------------------

./compileAndRun.sh compile

RUNNING THE PROJECT
-------------------

./compileAndRun.sh run

NOTE: It may take about a minute until the GUI pops up because, first, information (no data!) 
about all PVs stored on the appliances are retrieved.

FUNCTIONALITY OF THE PROGRAM
----------------------------

Depending on the selected appliance all on this appliance stored PVs are shown and selectable
for display. Or you can just click "Display random PV" and you'll be getting a randomly 
selected PV. For each displayed PV you'll see some information about this PV.

WHAT YOU SEE ON THE DISPLAY
---------------------------

The archived values of a PV are shown in the time span between the times given for 
"Archive parameters creation time:" and "Last archived event at:". The more the times for
"Archive parameters creation time:" and "First archived event at:" deviate from eachother
the further right the plotting of values starts. If both times only deviate from eachother
by, say, a few seconds to minutes plotted values will start at the left side of the display
frame.

For efficiency reasons not every single archived value is retrieved. Instead, you see
graphs showing the maximum, mean and minimum value in a time interval of a fixed length, 
called "bin". Standardly, the time span between the creation of the archive parameters
and the last archived sample is divided into 100 bins resulting in an interval period, a bin, of
x seconds. Then, for each bin the maximum, mean and minimum sample are calculated and retrieved.
For details on this please have a look at the "Processing of data" section in the EPICS
ARCHIVER APPLIANCE user guide. The calculation of these statistics works for both: scalar and
waveform PVs.
NOTE: you can change the amount of bins from 100 to, for example, 1000 if you need more detail in
Controller.getAndDisplayData: PVData pvData = new PVData(100);

For orientation purposes the zero line as well as the overall minimum and maximum value
are displayed.

KNOWN ERRORS
------------

Displaying some PVs doesn't (yet) work due to unknown reasons. You will get a 

org.json.JSONException: JSONArray[0] not found.

error but you can continue with displaying another PV without having to restart
the program.