Array rank functions for numerical types. More...

Functions
void	linToDB (float *arr, uint32_t len, float minDB)
	Mapping from linear range [-1, 1] to normalized dB range [-1, 1].
void	clip1 (float *arr, uint32_t len, uint32_t str=1)
	Clip array values between [-1, 1].
uint32_t	zeroCross (const float *src, uint32_t len, float prev)
	Returns number of zero-crossings in array.
uint32_t	zeroCrossFirst (const float *src, uint32_t len)
	Returns index of first zero-crossing or 0 if none detected.
uint32_t	zeroCrossN (const float *src, uint32_t len, float prev)
	Returns # of negative slope zero-crossings.
template<class T >
void	add (T dst, const T src, uint32_t len, uint32_t str=1)
	Add source array to destination array.
template<class T >
void	add (T dst, const T src1, const T *src2, uint32_t len, uint32_t str=1)
	Add two source arrays into destination array.
template<class T >
uint32_t	addToRing (T ring, uint32_t ringSize, uint32_t ringTap, const T src, uint32_t len)
	Sum elements from src into ring-buffer ring.
template<class T >
void	cluster (const T src, uint32_t indices, uint32_t &numIndices, T threshold)
	Finds elements that are within a threshold of their nearest neighbors.
template<class T >
T	dot (const T src1, const T src2, uint32_t len, uint32_t str=1)
	Returns dot-product of two arrays.
template<class T >
T	dot4 (const T src1, const T src2)
	Returns dot-product of two arrays of length 4.
template<class T >
void	extrema (const T *src, uint32_t len, uint32_t &indexMin, uint32_t &indexMax)
	Get indices of min and max values.
template<class T1 , class T2 , class T3 >
void	fitLine (const T1 *src, uint32_t len, T2 &slope, T3 &inter)
	Perform linear least squares fitting of array.
template<class Ts , class Tb >
void	histogram (const Ts src, uint32_t len, Tb bins, uint32_t numBins, Ts scale=1)
	Compute histogram of 'src'.
template<class T >
uint32_t	indexOfMax (const T *src, uint32_t len, uint32_t str=1)
	Returns index of maximum value.
template<class T >
uint32_t	indexOfMaxNorm (const T *src, uint32_t len, uint32_t str=1)
	Returns index of maximum normed value (i.e., magnitude)
template<class T >
uint32_t	indexOfMin (const T *src, uint32_t len)
	Returns index of minimum value.
void	indicesComplement (uint32_t *indices, uint32_t numIndices, uint32_t maxNumIndices)
	Sets indices [numIndices, maxNumIndices) to complement indices.
template<class T >
uint32_t	maxima (uint32_t dst, const T src, uint32_t len, uint32_t str=1)
	Locates local maxima and writes their indices into 'dst'.
template<class T >
T	mean (const T *src, uint32_t len, uint32_t str=1)
	Returns the mean (average) value of array values.
template<class T >
T	meanNorm (const T *src, uint32_t len, uint32_t str=1)
	Returns the mean norm of array values.
template<class T >
T	meanAbsDiff (const T *src, uint32_t len)
	Returns mean absolute difference of array values.
template<class T >
T	meanWeighted (const T src, T weights, uint32_t len)
	Returns weighted mean of array values.
template<class T >
T	meanWeightedIndex (const T *weights, uint32_t len)
	Returns weighted mean in [0, len) of indices of weights.
template<class T >
void	mirror_dp (T *arr, uint32_t len)
	Applies mirror isometry sequence [dp] from first half of array.
template<class T >
void	mirror_dq (T *arr, uint32_t len)
	Applies mirror isometry sequence [dq] from first half of array.
template<class T >
void	mul (T dst, const T src, uint32_t len, uint32_t str=1)
	Multiply destination array by source array.
template<class T >
void	mulBartlett (T *arr, uint32_t len)
	Multiply array by a Bartlett (triangle) window.
template<class T >
void	mulHalfWindow (T arr, const T src, uint32_t len)
template<class T >
double	normalize (T *arr, uint32_t len, double scale=1)
	Uniformly scale array values to fit in [-1, 1].
template<class T >
double	norm (const T *src, uint32_t len, uint32_t str=1)
	Returns norm of array values.
template<class T >
double	normTaxi (const T *src, uint32_t len, uint32_t str=1)
	Returns taxicab norm of array values (sum of absolute values).
template<class T >
T	nyquist (const T *src, uint32_t len, uint32_t str=1)
	Returns unnormalized Nyquist value for use with DFT.
template<class T >
T	rms (const T *src, uint32_t len, uint32_t str=1)
	Returns root mean square- the normalized norm.
template<class T >
uint32_t	slopeAbsMax (const T *src, uint32_t len)
	Returns index of absolute maximum slope in array.
template<class T >
uint32_t	slopeMax (const T *src, uint32_t len)
	Returns index of maximum slope in array.
template<class T >
void	sortInsertion (T *arr, uint32_t len)
	Insertion sort of elements.
template<class T >
void	sortInsertion (const T src, uint32_t indices, uint32_t numIndices)
	Insertion sort of indexed elements.
template<class T >
void	sortQuick (const T src, uint32_t indices, long beg, long end)
	Quick sort of elements.
template<class T >
T	sum (const T *src, uint32_t len, uint32_t str=1)
	Returns sum of values.
template<class T >
T	sumSquares (const T *src, uint32_t len, uint32_t str=1)
	Returns sum of values squared.
template<class T >
T	variance (const T *src, uint32_t len, uint32_t str=1)
	Variance (deviation from mean).
template<class T >
uint32_t	within (const T *src, uint32_t len, T threshold)
	Returns number of values within [-threshold, theshold].
template<class T >
uint32_t	within (const T *src, uint32_t len, T lo, T hi)
	Returns number of values within [lo, hi].
template<class T >
uint32_t	zeroCount (const T *src, uint32_t len, uint32_t str=1)
	Returns number of values that equal zero.

Detailed Description

Array rank functions for numerical types.

The following are names commonly used for input parameters.

'src' - array that will only be read from
'dst' - array that will be written to
'arr' - array that will be read from and written to, i.e. in-place
'len' - length of array
'stride' - how many elements to step through the array by
Many of these functions are numerically generic meaning that the object is required to understand one or more of arithmetic operators +, -, *, \, and/or relational operators <, <=, >, >=.

Function Documentation

uint32_t addToRing	(	T *	ring,
		uint32_t	ringSize,
		uint32_t	ringTap,
		const T *	src,
		uint32_t	len
	)

Sum elements from src into ring-buffer ring.

Returns the next tap index. This will not guaranteed to be in the range [0, ringSize).

void cluster	(	const T *	src,
		uint32_t *	indices,
		uint32_t &	numIndices,
		T	threshold
	)

Finds elements that are within a threshold of their nearest neighbors.

Parameters:

[in]	src	Source array of elements
[in]	indices	Index array used for iterating the source array.
[out]	indices	Cluster indices.
[in]	numIndices	Number of source indices.
[out]	numIndices	Number of cluster indices.
[in]	threshold	Magnitude threshold of cluster.

void gam::arr::fitLine	(	const T1 *	src,
		uint32_t	len,
		T2 &	slope,
		T3 &	inter
	)

Perform linear least squares fitting of array.

The independent axis is the array indices, i. The best fit line equation is y = inter + slope * i.

void histogram	(	const Ts *	src,
		uint32_t	len,
		Tb *	bins,
		uint32_t	numBins,
		Ts	scale = `1`
	)

Compute histogram of 'src'.

Values in 'src' are tallied and placed in 'bins', where the index of the bin is the integer part of the source values. Source values greater than the number of bins are ignored. The scale and offset parameters can be used to put the src values into the proper range.

void indicesComplement	(	uint32_t *	indices,
		uint32_t	numIndices,
		uint32_t	maxNumIndices
	)

Sets indices [numIndices, maxNumIndices) to complement indices.

Indices must be sorted from low to high.

uint32_t maxima	(	uint32_t *	dst,
		const T *	src,
		uint32_t	len,
		uint32_t	str = `1`
	)

Locates local maxima and writes their indices into 'dst'.

Returns number of maxima found.

T meanWeighted	(	const T *	src,
		T *	weights,
		uint32_t	len
	)

Returns weighted mean of array values.

Weights must be positive.

T meanWeightedIndex	(	const T *	weights,
		uint32_t	len
	)

Returns weighted mean in [0, len) of indices of weights.

Weights must be positive. Can be used to compute centroid of spectrum.

void mirror_dp	(	T *	arr,
		uint32_t	len
	)

Applies mirror isometry sequence [dp] from first half of array.

The sequence of mirror isometries are identity (d) and rotation (p). The first len/2 elements of the array are mirrored.
Ex.: [ 1, 2, 3, 4, x, x, x, x] -> [ 1, 2, 3, 4,-4,-3,-2,-1]

void mirror_dq	(	T *	arr,
		uint32_t	len
	)

Applies mirror isometry sequence [dq] from first half of array.

The sequence of mirror isometries are identity (d) and glide relfection (q). The first len/2 elements of the array are mirrored.
Ex.: [ 1, 2, 3, 4, x, x, x, x] -> [ 1, 2, 3, 4,-1,-2,-3,-4]

void mulBartlett	(	T *	arr,
		uint32_t	len
	)

Multiply array by a Bartlett (triangle) window.

Works only for even sized arrays.

void mulHalfWindow	(	T *	arr,
		const T *	src,
		uint32_t	len
	)

Multiply 'arr' by 'src' where 'src' is the first 'len'/2 + 1 elements of a symmetric window.

double normalize	(	T *	arr,
		uint32_t	len,
		double	scale = `1`
	)

Uniformly scale array values to fit in [-1, 1].

Returns the applied normalization multiplication factor.

void sortInsertion	(	T *	arr,
		uint32_t	len
	)

Insertion sort of elements.

Elements are sorted from lowest to highest. This sort is fastest for small length arrays and mostly sorted sets.

void sortInsertion	(	const T *	src,
		uint32_t *	indices,
		uint32_t	numIndices
	)

Insertion sort of indexed elements.

Elements are sorted from lowest to highest. This sort is fastest for small length arrays and mostly sorted sets.

void sortQuick	(	const T *	src,
		uint32_t *	indices,
		long	beg,
		long	end
	)

Quick sort of elements.

Elements are sorted from lowest to highest.

uint32_t zeroCross	(	const float *	src,
		uint32_t	len,
		float	prev
	)

Returns number of zero-crossings in array.

'prev' is the last value from the previous buffer.

uint32_t zeroCrossN	(	const float *	src,
		uint32_t	len,
		float	prev
	)

Returns # of negative slope zero-crossings.

'prev' is the last value from the previous buffer.

Functions

Detailed Description

Function Documentation