Abstract base class for model variables. More...

#include <creativity/data/Variable.hpp>

Classes
class	SizeError
	Exception class thrown when attempting to populate a column from a source of an incompatible or unknown size. More...

Public Member Functions
virtual	~Variable ()=default
	Virtual destructor.

virtual std::string	name () const =0
	Returns a name for this variable.

virtual std::string	nameBracketed (const std::string &bracketL="(", const std::string &bracketR=")") const
	Returns a name for this variable, but with surrounding brackets if this variable needs it–for example, for a multiplication of two variables. More...

virtual void	populate (Eigen::Ref< Eigen::VectorXd > column, unsigned int offset=0, unsigned int trim=0) const =0
	Populates the given column reference with this variable's values. More...

Eigen::VectorXd	values (unsigned int rows=0, unsigned int offset=0, unsigned int trim=0) const
	Shortcut wrapper around populate that creates a new column of the given size, calls populate() with it, then returns it. More...

virtual unsigned int	size () const =0
	Returns the intrinsic size of this data. More...

Detailed Description

Abstract base class for model variables.

Subclasses of this are used for simple variables, multiplications of variables, etc.

Member Function Documentation

§ nameBracketed()

virtual std::string creativity::data::Variable::nameBracketed	(	const std::string &	bracketL = `"("`,
		const std::string &	bracketR = `")"`
	)		const

virtual

Returns a name for this variable, but with surrounding brackets if this variable needs it–for example, for a multiplication of two variables.

For simple variables and constants, and some non-simple variables such as Logarithm, the brackets are not needed.

Parameters

bracketL	the left bracket; defaults to a left parenthesis
bracketR	the right bracket; defaults to a right parenthesis

Reimplemented in creativity::data::Logarithm, creativity::data::Exponential, creativity::data::SimpleVariable, and creativity::data::ConstantVariable.

§ populate()

virtual void creativity::data::Variable::populate	(	Eigen::Ref< Eigen::VectorXd >	column,
		unsigned int	offset = `0`,
		unsigned int	trim = `0`
	)		const

pure virtual

Populates the given column reference with this variable's values.

The offset and trim parameters allow you to exclude leading or trailing elements from the source data. Note that these elements are not excluded from the populated column: for example, when the data is backed by a column, source.size() - offset - trim must equal column.size().

Parameters

column	the column to populate
offset	if specified and non-zero, the number of values to skip from the beginning of the source data (but NOT `column`).
trim	if specified and non-zero, the number of values to leave off the end of the source data (but NOT `column`).

Exceptions

Variable::SizeError if the given column's size, after adjusting for offset and trim, is not compatible with this variable's size.

Implemented in creativity::data::Logarithm, creativity::data::Exponential, creativity::data::Power, creativity::data::Division, creativity::data::Addition, creativity::data::Multiplication, creativity::data::SimpleVariable, and creativity::data::ConstantVariable.

§ size()

virtual unsigned int creativity::data::Variable::size ( ) const

pure virtual

Returns the intrinsic size of this data.

If this Variable has no such intrinsic size, such as a ConstantVariable, this throws a SizeError exception. If this variable is an expression with multiple sizes, this method return can return any of the sizes.

Implemented in creativity::data::UnaryExpr, creativity::data::BinaryExpr, creativity::data::SimpleVariable, and creativity::data::ConstantVariable.

§ values()

Eigen::VectorXd creativity::data::Variable::values	(	unsigned int	rows = `0`,
		unsigned int	offset = `0`,
		unsigned int	trim = `0`
	)		const

Shortcut wrapper around populate that creates a new column of the given size, calls populate() with it, then returns it.

If rows equals 0 (the default if not specified), the size is determined by a call to size(). Note, however, that size() will throw an exception if called on a Variable without an implied size, typically a ConstantVariable.

Inheritance diagram for creativity::data::Variable:

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Collaboration diagram for creativity::data::Variable: