vector_utils Namespace Reference

Helpers for spacing analysis and axis inference from coordinate sets. More...

Functions
bool	get_spacing_uniform (std::vector< float > &spacing, const std::set< float > &unsorted_block_poss, double epsilon=1e-4)
	Compute spacings between sorted unique values and test uniformity.
const std::set< float > &	get_largest_vector (const std::set< float > &x, const std::set< float > &y, const std::set< float > &z)
	Return the largest of three sets and report inferred axial direction.
void	find_unique_values_1D (std::set< float > &values, const std::vector< float > &input)
	Collect unique values from a 1D vector.
void	find_unique_values_2D (std::set< float > &values, const std::vector< std::vector< float > > &input)
	Collect unique values from a 2D vector (matrix).

Detailed Description

Helpers for spacing analysis and axis inference from coordinate sets.

• vector_utils::get_spacing_uniform computes successive spacings between sorted unique values and tests if they are uniform within a tolerance.
• vector_utils::getLargestVector returns the largest of three coordinate sets and logs which axis is inferred as “axial”.

Function Documentation

get_spacing_uniform()

bool vector_utils::get_spacing_uniform ( std::vector< float > & spacing, const std::set< float > & unsorted_block_poss, double epsilon = 1e-4 )

inline

Compute spacings between sorted unique values and test uniformity.

Parameters

spacing	Output vector. Appends |x[i] - x[i-1]| for i=1..N-1, where x is the sorted version of unsorted_block_poss.
unsorted_block_poss	Set of unique positions (e.g., angles or translations).
epsilon	Tolerance for uniformity check (default 1e-4).

Returns

True if all spacings differ from the first spacing by <= epsilon, false otherwise.

• If spacing ends up empty (e.g., input size < 2), returns true (trivially uniform).

References get_spacing_uniform().

Referenced by get_spacing_uniform(), and stir::PETSIRDInfo::PETSIRDInfo().

get_largest_vector()

const std::set< float > & vector_utils::get_largest_vector	(	const std::set< float > &	x,
		const std::set< float > &	y,
		const std::set< float > &	z )

Return the largest of three sets and report inferred axial direction.

Parameters

x	Values along X.
y	Values along Y.
z	Values along Z.

Returns

Const reference to the largest set among x, y, z.

Logs the index of the inferred axial direction: 0 (x), 1 (y), or 2 (z).

References get_largest_vector().

Referenced by get_largest_vector(), and stir::PETSIRDInfo::PETSIRDInfo().

find_unique_values_1D()

void vector_utils::find_unique_values_1D	(	std::set< float > &	values,
		const std::vector< float > &	input )

Collect unique values from a 1D vector.

Parameters

values	Output set for unique values.
input	Input vector.

References find_unique_values_1D().

Referenced by find_unique_values_1D().

find_unique_values_2D()

void vector_utils::find_unique_values_2D	(	std::set< float > &	values,
		const std::vector< std::vector< float > > &	input )

Collect unique values from a 2D vector (matrix).

Parameters

values	Output set for unique values.
input	Input 2D vector [rows][cols].

References find_unique_values_2D().

Referenced by find_unique_values_2D(), and stir::PETSIRDInfo::PETSIRDInfo().