Buildings.Fluid.Utilities

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Buildings.Fluid.Utilities

Package with utility functions

Information

This package contains utility classes that are used by the package Buildings.Fluid.

Extends from Modelica.Icons.Package (Icon for standard packages).

Package Content

Name	Description
extendedPolynomial	Polynomial that is linearly extended at user specified values
polynomial	Polynomial, used because OpenModelica 1.4.3 does not expand the sum() into a scalar
Examples	Collection of models that illustrate model use and test models
BaseClasses	Package with base classes for Buildings.Fluid.Utilities

Buildings.Fluid.Utilities.extendedPolynomial

Polynomial that is linearly extended at user specified values

Information

For x between the bounds x_min < x < x_max, this function defines a polynomial

y = ∑_i=1ⁿ c_i x^i-1

where n > 1 and x_min, x_max are parameters. For x < x_min and x > x_max, the polynomial is replaced by a linear function in such a way that the first derivative is continuous everywhere.

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Description
Real	x	x value
Real	c[:]	Polynomial coefficients
Real	xMin	Minimum x value for polynomial
Real	xMax	Maximum x value for polynomial

Outputs

Type	Name	Description
Real	y	y value

Modelica definition

function extendedPolynomial "Polynomial that is linearly extended at user specified values" annotation(derivative=BaseClasses.der_extendedPolynomial); extends Modelica.Icons.Function; input Real x "x value"; input Real[:] c "Polynomial coefficients"; input Real xMin "Minimum x value for polynomial"; input Real xMax "Maximum x value for polynomial"; output Real y "y value"; protected Integer N = size(c,1) "Number of coefficients"; algorithm if x < xMin then y := c[1]; for i in 2:N loop y := y + xMin^(i - 1)*c[i] + (x - xMin)*(i - 1)*xMin^(i - 2)*c[i]; end for; elseif x < xMax then y := c[1]; for i in 2:N loop y := y + x^(i - 1)*c[i]; end for; else y := c[1]; for i in 2:N loop y := y + xMax^(i - 1)*c[i] + (x - xMax)*(i - 1)*xMax^(i - 2)*c[i]; end for; end if; end extendedPolynomial;

Buildings.Fluid.Utilities.polynomial

Polynomial, used because OpenModelica 1.4.3 does not expand the sum() into a scalar

Information

Function that computes

y = ∑_i=1ⁿ c_i x^i-1

Extends from Modelica.Icons.Function (Icon for functions).

Inputs

Type	Name	Default	Description
Real	c[:]		Coefficients
Real	x		Independent variable

Outputs

Type	Name	Description
Real	y	Dependent variable

Modelica definition

function polynomial "Polynomial, used because OpenModelica 1.4.3 does not expand the sum() into a scalar" extends Modelica.Icons.Function; input Real[:] c "Coefficients"; input Real x "Independent variable"; output Real y "Dependent variable"; algorithm y := c[1]; for i in 2 : size(c,1) loop y := y + x^(i-1) * c[i]; end for; end polynomial;

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