PiecewiseLinearFunction

(class from pyomo.core.kernel.piecewise_library.transforms)

class pyomo.core.kernel.piecewise_library.transforms.PiecewiseLinearFunction(breakpoints, values, validate=True, **kwds)[source]

Bases: object

A piecewise linear function

Piecewise linear functions are defined by a list of breakpoints and a list function values corresponding to each breakpoint. The function value between breakpoints is implied through linear interpolation.

Parameters:

  • breakpoints (list) – The list of function breakpoints.

  • values (list) – The list of function values (one for each breakpoint).

  • validate (bool) – Indicates whether or not to perform validation of the input data. The default is True. Validation can be performed manually after the piecewise object is created by calling the validate() method. Validation should be performed any time the inputs are changed (e.g., when using mutable parameters in the breakpoints list).

  • **kwds – Additional keywords are passed to the validate() method when the validate keyword is True; otherwise, they are ignored.

__init__(breakpoints, values, validate=True, **kwds)[source]

Methods

__init__(breakpoints, values[, validate])

validate([equal_slopes_tolerance])

Validate this piecewise linear function by verifying various properties of the breakpoints and values lists (e.g., that the list of breakpoints is nondecreasing).

Attributes

breakpoints

The set of breakpoints used to defined this function

values

The set of values used to defined this function

Member Documentation

validate(equal_slopes_tolerance=1e-06)[source]

Validate this piecewise linear function by verifying various properties of the breakpoints and values lists (e.g., that the list of breakpoints is nondecreasing).

Parameters:

equal_slopes_tolerance (float) – Tolerance used check if consecutive slopes are nearly equal. If any are found, validation will fail. Default is 1e-6.

Returns:

a function characterization code (see util.characterize_function())

Return type:

int

Raises:

PiecewiseValidationError – if validation fails

property breakpoints

The set of breakpoints used to defined this function

property values

The set of values used to defined this function