Load From Data File
Several sets of polar data may be displayed in the plot by loading them from appropriately formatted data
files.

Acceptable Polar Data Formatting

Data should be in a tab or comma delimited text file (.txt or .csv).

File data should be in columns, with the first column containing angles and subsequent columns
containing polar data (or radius information), such as level, magnitude, etc, for the corresponding angle.

Any lines at the top of the file starting with *, #, or ; will be ignored as comment lines.

If any angle value exceeds 90 or is less than -90, the angular units will be assumed to be degrees.
Otherwise, the angular units will be assumed to be radians. Degrees can be manually chosen using the
'Angular Units:' keyword, described below.

Several keys will be recognized for setting specific properties for the polar data. These keys, and
their corresponding values, must be set in the file above the polar data, after any comment lines.
The number of values following the key (each separated by the chosen delimiter) must match the number
of polar data columns, so that the keyword + value columns is equal to the angle + polar data columns.

Channel Label: Text value, names the corresponding column of polar data.

Units: Text value, identifies the units of the polar data. If the units
value begins with dB, then the polar data will be treated as decibel values. Otherwise, it will not.

Angular Units: Text value, must be ยบ or deg to set the angular units
to degrees. Otherwise, the angular units will be set to radians, unless at least one value exceeds
+/- 90 degrees.

dB Multiplier: Numerical value, identifies multiplier that should be used
to convert between decibel and non-decibel values of the polar data. This value will typically be 20, but
may also be 10.

dB Reference: Numerical value, identifies the reference that should be used
to convert between decibel and non-decibel values of the polar data. This value will typically be 1.0, but
may be other values, such as 2e-5 or 0.00002 in the case of sound levels.