independentVarPts — Simple definition of independent breakpoints
independentVarPts : varID, [name], [units], [sign], [extrapolate], [interpolate]
(#PCDATA)
varID- the XML id of the input signal corresponding to this independent variable
name(optional) - the name of the function's independent variable input signal
units(optional) - the units of measure for the independent variable
sign(optional) - the sign convention for the independent variable
extrapolate(optional) - extrapolation flags for IV out-of-bounds (default is neither) (enumerated)
neither
min
max
both
interpolate(optional) - Interpolation flags for independent variable (default is linear) (enumerated)
discrete
floor
ceiling
linear
quadraticSpline
cubicSpline
An independentVarPts element is a simple list of breakpoints and contains a mandatory varID identifier as well as optional name, units, and sign convention attributes. An optional extrapolate attribute describes how to extrapolate the output value when the input value exceeds specified values (default is 'neither,' meaning the value of the table is held constant at the nearest defined value). An optional interpolate attribute indicates how to perform the interpolation within the table (supporting discrete, linear, cubic or quadratic splines). There are three different discrete options: 'discrete' means nearest-neighbor, with an exact mid-point value being rounded in the positive direction; 'floor' means the function takes on the value associated with the next (numerically) higher independent breakpoint as soon as original value is exceeded, and 'ceiling' means the function holds the value associated with each breakpoint until the next (numerically) higher breakpoint value is reached by the independent argument. The default interpolation attribute value is 'linear.' This element is used for simple functions that don't share breakpoint or table values with other functions.