watertap.core.util package

Subpackages

• watertap.core.util.model_diagnostics package
  • Submodules
  • watertap.core.util.model_diagnostics.infeasible module
    • print_close_to_bounds()
    • print_constraints_close_to_bounds()
    • print_infeasible_bounds()
    • print_infeasible_constraints()
    • print_variables_close_to_bounds()
  • watertap.core.util.model_diagnostics.ipopt_initialization module
    • assert_no_initialization_perturbation()
    • generate_initialization_perturbation()
    • print_initialization_perturbation()
  • Module contents

Submodules

watertap.core.util.chemistry module

watertap.core.util.chemistry.get_charge(watertap_name: str) → int

Gets charge from WaterTAP formatted names. :param watertap_name: string name of a solute in WaterTAP format :return charge: integer value of charge

watertap.core.util.chemistry.get_charge_group(charge: int) → str

Categorizes molecule based on its charge.

Parameters:

charge – integer value for charge

Return group:

string name for charge group

watertap.core.util.chemistry.get_molar_mass(watertap_name: str) → float

Extracts atomic weight data from a periodic table file to generate the molar mass of a chemical substance. TODO: additional testing for complex solutes such as CH3CO2H, [UO2]2[OH]4, etc. :param watertap_name: string name of a solute in WaterTAP format :return molar_mass: float value for molar mass of solute

watertap.core.util.chemistry.get_molar_mass_quantity(watertap_name: str, units=<pyomo.core.expr.numeric_expr.NPV_DivisionExpression object>)

Extracts atomic weight data from a periodic table file to generate the molar mass of a chemical substance in pint units. Since get_molar_mass returns only the value, which has inherent units of g/mol, this function converts to kg/mol by default, the units used for molecular weight by convention in WaterTAP.

Parameters:

watertap_name – string name of a solute in WaterTAP format

Return desired_quantity:

molar mass of solute in pint units. Conversion from g/mol to kg/mol by default.

watertap.core.util.initialization module

This module contains utility functions for initialization of WaterTAP models.

watertap.core.util.initialization.assert_degrees_of_freedom(blk, expected_dof)

Assert that degrees of freedom are expected_dof. If not expected_dof, throw an error and stop.

Keyword Arguments:

• blk – block to check

• expected_dof – Integer number of degrees of freedom blk should have

Returns:

None

watertap.core.util.initialization.assert_no_degrees_of_freedom(blk)

Assert that degrees of freedom are 0. If blk has non-zero degrees of freedom, throw an error and stop.

Keyword Arguments:

blk – block to check

Returns:

None

watertap.core.util.initialization.check_dof(blk, fail_flag=False, logger=<LoggerAdapter idaes.watertap.core.util.initialization (INFO)>, expected_dof=0)

Check that degrees of freedom are 0, or the expected amount expected_dof. If not 0 or expected_dof, either throw a warning and continue or throw an error and stop.

Keyword Arguments:

• blk – block to check

• fail_flag – Boolean argument to specify error or warning

• (Default – fail_flag=False produces logger warning. Set fail_flag=True to raise an error and stop the initialization routine.)

• logger – Optional argument for loading idaes.getInitLogger object (e.g., logger=init_log)

• expected_dof – Integer number of degrees of freedom blk should have

Returns:

None

watertap.core.util.initialization.check_solve(results, checkpoint=None, logger=<LoggerAdapter idaes.watertap.core.util.initialization (INFO)>, fail_flag=False)

Check that solver termination is optimal and OK in an initialization routine. If the check fails, proceed through initialization with only a logger warning by default, or set fail_flag=True to raise an error. This should also work for checking a solve outside of an initialization routine.

Keyword Arguments:

• results – solver results

• checkpoint – Optional string argument to specify the step of initialization being checked (e.g., checkpoint=”Initialization step 1: solve indexed blocks”)

• logger – Optional argument for loading idaes.getInitLogger object (e.g., logger=init_log)

• fail_flag – Boolean argument to specify error or warning (Default: fail_flag=False produces logger warning. set fail_flag=True to raise an error and stop the initialization routine.)

Returns:

None

watertap.core.util.initialization.interval_initializer(blk, feasibility_tol=1e-06, default_initial_value=0.0, logger=<LoggerAdapter idaes.watertap.core.util.initialization (INFO)>, fail_flag=False)

Improve the initialization of blk utilizing interval arithmetic.

Keyword Arguments:

• blk – block to initialize

• feasibility_tol – tolerance to use for FBBT (default: 1e-6)

• default_initial_value – set uninitialized variables to this value (default: 0.0)

• logger – logger to use (default: watertap.core.util.initialization)

• fail_flag – Boolean argument to specify error or warning (Default: fail_flag=False produces logger warning. set fail_flag=True to raise an error and when interval initialization encounters exception.)

Returns:

None

watertap.core.util.misc module

watertap.core.util.misc.is_constant_up_to_units(expr)

Determines if a Pyomo expression is constant, even if units are involved :param expr: A Pyomo expression or a numeric value

Returns:

True if the expr is constant besides units, False otherwise

Return type:

bool

watertap.core.util.misc.smooth_heaviside(x, k)

Provides a smooth, continuous approximation of a discontinuous function :param x: Independent variable :param k: Smoothing parameter representing the slope of the discontinuity

Returns:

Continuous approximation of a discontinuous function

Return type:

function

watertap.core.util.scaling module

This module contains a utility function for the scaling of WaterTAP property model constraints.

Module contents