# Structure of a DataSet

In order to modify or generate a DataSet, it is important to understand how they are constructed.

The structure of a DataSet contains three types of data:
• Axes refer to the independent axes along which data can be plotted in a view.
• Quantities refer to the types of data that can be plotted along a specified axis.
• MetaData refers to additional data that pertains to a DataSet that affects how POSTFEKO interprets the DataSet.

The additional data field refers to the actual values of the results. The indexing of the data is dependent on the structure of the axes and quantities that were defined. Since the data fields should not be accessed directly, it is not discussed here. Rather, the discussion of the proper access methods will follow.

Table 1 shows all of the base units currently supported by POSTFEKO. For all Axes and Quantities, the units need to be specified to help ensure that POSTFEKO knows how to manage the values. More complex units may be constructed out of the base unit from the table by using the operators / and ˆ. For example, acceleration can be written as m/sˆ2.

Data can also consist of different types of data. Table 2 indicates the supported data types.

Table 1. Supported units
Quantity Unit
Distance m
inch
feet
mile
mil
Angle deg
Frequency Hz
Time s
min
hr
Mass g
t
Temperature C
K
F
Current A
Charge C
Force N
Potential difference V
Resistance Ohm
Conductivity S
Power W
Capacitance F
Inductance H
Table 2. Supported data types
Data type Description
scalar Any real valued data.
complex Complex values; values containing real and imaginary components.
boolean Either a true or false value.