Piecewise Conversion Calculations

class ionworkspipeline.calculations.SlopesToKnots(base_parameter_name: str, breakpoint_values: list[float], breakpoint_parameter_name: str)

Converts slopes and initial value to knot values for piecewise linear interpolation.

This calculation takes as input: - An initial value at the first breakpoint - Slopes for each segment between consecutive breakpoints

And outputs: - The value at each breakpoint (knot values)

The conversion follows: y_{i+1} = y_i + slope_i * (x_{i+1} - x_i)

Parameters

base_parameter_namestr

The name of the parameter (e.g., “Particle diffusion time [s]”)

breakpoint_valueslist[float]

List of breakpoint values (e.g., [0.0, 0.5, 1.0])

breakpoint_parameter_namestr

Name of the breakpoint parameter (e.g., “SOC”, “Temperature [K]”)

Examples

>>> import ionworkspipeline as iwp
>>> calc = iwp.calculations.SlopesToKnots(
...     base_parameter_name="Particle diffusion time [s]",
...     breakpoint_values=[0.0, 0.5, 1.0],
...     breakpoint_parameter_name="SOC",
... )
>>> params = iwp.ParameterValues({
...     "Particle diffusion time at SOC 0 [s]": 500.0,
...     "Particle diffusion time slope from SOC 0 to 0.5 [s]": 1000.0,
...     "Particle diffusion time slope from SOC 0.5 to 1 [s]": 2000.0,
... })
>>> result = calc.run(params)
>>> result["Particle diffusion time at SOC 0 [s]"]
500.0
>>> result["Particle diffusion time at SOC 0.5 [s]"]
1000.0
>>> result["Particle diffusion time at SOC 1 [s]"]
2000.0

Extends: ionworkspipeline.calculations.calculation.Calculation

property inputs

Returns the list of input parameters needed for this calculation.

This includes the initial value and all slopes.

property outputs

Returns the list of output parameters produced by this calculation.

This includes all knot values at the breakpoints.

run(parameter_values: ParameterValues) → ParameterValues

Convert slopes and initial value to knot values.

Parameters

parameter_valuesdict

Dictionary containing: - Initial value at first breakpoint - Slopes for each segment

Returns

dict

Dictionary containing knot values at all breakpoints

class ionworkspipeline.calculations.SlopesToKnots2D(base_parameter_name: str, breakpoint1_values: list[float], breakpoint1_parameter_name: str, breakpoint2_values: list[float], breakpoint2_parameter_name: str)

Converts slopes and initial value to knot values for 2D piecewise linear interpolation.

This calculation takes as input: - An initial value at (bp1_0, bp2_0) - Slopes along dimension 1 for the first row (at bp2_0) - Slopes along dimension 2 for all subsequent rows

And outputs: - The value at each 2D grid point (knot values)

The conversion follows the same strategy as PiecewiseInterpolation2D slopes mode: 1. Start with initial value at (bp1_0, bp2_0) 2. Use bp1-slopes to fill first row 3. Use bp2-slopes to fill remaining rows

Parameters

base_parameter_namestr

The name of the parameter (e.g., “Diffusivity [m2.s-1]”)

breakpoint1_valueslist[float]

List of first dimension breakpoint values (e.g., [0.0, 0.5, 1.0])

breakpoint1_parameter_namestr

Name of the first breakpoint parameter (e.g., “SOC”)

breakpoint2_valueslist[float]

List of second dimension breakpoint values (e.g., [273.15, 298.15])

breakpoint2_parameter_namestr

Name of the second breakpoint parameter (e.g., “Temperature [K]”)

Examples

>>> import ionworkspipeline as iwp
>>> calc = iwp.calculations.SlopesToKnots2D(
...     base_parameter_name="Diffusivity [m2.s-1]",
...     breakpoint1_values=[0.0, 1.0],
...     breakpoint1_parameter_name="SOC",
...     breakpoint2_values=[273.15, 323.15],
...     breakpoint2_parameter_name="Temperature [K]",
... )
>>> params = iwp.ParameterValues({
...     "Diffusivity at SOC 0, Temperature [K] 273.15 [m2.s-1]": 1e-14,
...     "Diffusivity SOC-slope from SOC 0 to 1 at Temperature [K] 273.15 [m2.s-1]": 2e-14,
...     "Diffusivity Temperature [K]-slope from Temperature [K] 273.15 to 323.15 at SOC 0 [m2.s-1]": 2e-15,
...     "Diffusivity Temperature [K]-slope from Temperature [K] 273.15 to 323.15 at SOC 1 [m2.s-1]": 2e-15,
... })
>>> result = calc.run(params)
>>> result["Diffusivity at SOC 0, Temperature [K] 273.15 [m2.s-1]"]
1e-14

Extends: ionworkspipeline.calculations.calculation.Calculation

property inputs

Returns the list of input parameters needed for this calculation.

This includes the initial value and all slopes.

property outputs

Returns the list of output parameters produced by this calculation.

This includes all knot values at the 2D grid points.

run(parameter_values: ParameterValues) → ParameterValues

Convert 2D slopes and initial value to knot values.

Parameters

parameter_valuesdict

Dictionary containing: - Initial value at (bp1_0, bp2_0) - bp1-slopes for first row - bp2-slopes for all columns

Returns

dict

Dictionary containing knot values at all 2D grid points