Class ConstantCurve

  • All Implemented Interfaces:
    Curve, ParameterizedData, java.io.Serializable, Bean, ImmutableBean

    public final class ConstantCurve
    extends java.lang.Object
    implements Curve, ImmutableBean, java.io.Serializable
    A curve based on a single constant value.

    This class defines a curve in terms of a single parameter, the constant value. When queried, yValue(double) always returns the constant value. The sensitivity is 1 and the first derivative is 0.

    The curve has one parameter, the value of the constant.

    See Also:
    Serialized Form
    • Method Detail

      • of

        public static ConstantCurve of​(java.lang.String name,
                                       double yValue)
        Creates a constant curve with a specific value.
        Parameters:
        name - the curve name
        yValue - the constant y-value
        Returns:
        the curve
      • of

        public static ConstantCurve of​(CurveName name,
                                       double yValue)
        Creates a constant curve with a specific value.
        Parameters:
        name - the curve name
        yValue - the constant y-value
        Returns:
        the curve
      • of

        public static ConstantCurve of​(CurveMetadata metadata,
                                       double yValue)
        Creates a constant curve with a specific value.
        Parameters:
        metadata - the curve metadata
        yValue - the constant y-value
        Returns:
        the curve
      • getParameterCount

        public int getParameterCount()
        Description copied from interface: ParameterizedData
        Gets the number of parameters.

        This returns the number of parameters, which can be used to create a loop to access the other methods on this interface.

        Specified by:
        getParameterCount in interface ParameterizedData
        Returns:
        the number of parameters
      • getParameter

        public double getParameter​(int parameterIndex)
        Description copied from interface: ParameterizedData
        Gets the value of the parameter at the specified index.
        Specified by:
        getParameter in interface ParameterizedData
        Parameters:
        parameterIndex - the zero-based index of the parameter to get
        Returns:
        the value of the parameter
      • withParameter

        public ConstantCurve withParameter​(int parameterIndex,
                                           double newValue)
        Description copied from interface: ParameterizedData
        Returns a copy of the data with the value at the specified index altered.

        This instance is immutable and unaffected by this method call.

        Specified by:
        withParameter in interface Curve
        Specified by:
        withParameter in interface ParameterizedData
        Parameters:
        parameterIndex - the zero-based index of the parameter to get
        newValue - the new value for the specified parameter
        Returns:
        a parameterized data instance based on this with the specified parameter altered
      • withPerturbation

        public ConstantCurve withPerturbation​(ParameterPerturbation perturbation)
        Description copied from interface: ParameterizedData
        Returns a perturbed copy of the data.

        The perturbation instance will be invoked once for each parameter in this instance, returning the perturbed value for that parameter. The result of this method is a new instance that is based on those perturbed values.

        This instance is immutable and unaffected by this method call.

        Specified by:
        withPerturbation in interface Curve
        Specified by:
        withPerturbation in interface ParameterizedData
        Parameters:
        perturbation - the perturbation to apply
        Returns:
        a parameterized data instance based on this with the specified perturbation applied
      • yValue

        public double yValue​(double x)
        Description copied from interface: Curve
        Computes the y-value for the specified x-value.
        Specified by:
        yValue in interface Curve
        Parameters:
        x - the x-value to find the y-value for
        Returns:
        the value at the x-value
      • yValueParameterSensitivity

        public UnitParameterSensitivity yValueParameterSensitivity​(double x)
        Description copied from interface: Curve
        Computes the sensitivity of the y-value with respect to the curve parameters.

        This returns an array with one element for each parameter of the curve. The array contains the sensitivity of the y-value at the specified x-value to each parameter.

        Specified by:
        yValueParameterSensitivity in interface Curve
        Parameters:
        x - the x-value at which the parameter sensitivity is computed
        Returns:
        the sensitivity
      • firstDerivative

        public double firstDerivative​(double x)
        Description copied from interface: Curve
        Computes the first derivative of the curve.

        The first derivative is dy/dx.

        Specified by:
        firstDerivative in interface Curve
        Parameters:
        x - the x-value at which the derivative is taken
        Returns:
        the first derivative
      • withMetadata

        public ConstantCurve withMetadata​(CurveMetadata metadata)
        Description copied from interface: Curve
        Returns a new curve with the specified metadata.

        This allows the metadata of the curve to be changed while retaining all other information. If parameter metadata is present, the size of the list must match the number of parameters of this curve.

        Specified by:
        withMetadata in interface Curve
        Parameters:
        metadata - the new metadata for the curve
        Returns:
        the new curve
      • meta

        public static ConstantCurve.Meta meta()
        The meta-bean for ConstantCurve.
        Returns:
        the meta-bean, not null
      • getMetadata

        public CurveMetadata getMetadata()
        Gets the curve metadata.

        The metadata will not normally have parameter metadata.

        Specified by:
        getMetadata in interface Curve
        Returns:
        the value of the property, not null
      • getYValue

        public double getYValue()
        Gets the single y-value.
        Returns:
        the value of the property
      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object