homkermap.h File Reference

Homogeneous kernel map (Homogeneous kernel map) More...

#include "generic.h"
#include <math.h>

Typedefs
typedef OPAQUE	VlHomogeneousKernelMap
	Homogeneous kernel map object.

Enumerations
enum	VlHomogeneousKernelType { VlHomogeneousKernelIntersection = 0, VlHomogeneousKernelChi2, VlHomogeneousKernelJS }
	Type of kernel. More...
enum	VlHomogeneousKernelMapWindowType { VlHomogeneousKernelMapWindowUniform = 0, VlHomogeneousKernelMapWindowRectangular = 1 }
	Type of spectral windowing function. More...

Functions
Create and destroy
VlHomogeneousKernelMap *	vl_homogeneouskernelmap_new (VlHomogeneousKernelType kernelType, double gamma, vl_size order, double period, VlHomogeneousKernelMapWindowType windowType)
	Create a new homgeneous kernel map.
void	vl_homogeneouskernelmap_delete (VlHomogeneousKernelMap *self)
	Delete an object instance.
Process data
void	vl_homogeneouskernelmap_evaluate_d (VlHomogeneousKernelMap const *self, double *destination, vl_size stride, double x)
	Evaluate map.
void	vl_homogeneouskernelmap_evaluate_f (VlHomogeneousKernelMap const *self, float *destination, vl_size stride, double x)
Retrieve data and parameters
vl_size	vl_homogeneouskernelmap_get_order (VlHomogeneousKernelMap const *self)
	Get the map order.
vl_size	vl_homogeneouskernelmap_get_dimension (VlHomogeneousKernelMap const *self)
	Get the map dimension.
VlHomogeneousKernelType	vl_homogeneouskernelmap_get_kernel_type (VlHomogeneousKernelMap const *self)
	Get the kernel type.
VlHomogeneousKernelMapWindowType	vl_homogeneouskernelmap_get_window_type (VlHomogeneousKernelMap const *self)
	Get the window type.

---

Detailed Description

Author:

Andrea Vedaldi

---

Enumeration Type Documentation

enum VlHomogeneousKernelMapWindowType

Enumerator:

VlHomogeneousKernelMapWindowUniform	uniform window
VlHomogeneousKernelMapWindowRectangular	rectangular window

enum VlHomogeneousKernelType

Enumerator:

VlHomogeneousKernelIntersection	intersection kernel
VlHomogeneousKernelChi2	Chi2 kernel
VlHomogeneousKernelJS	Jensen-Shannon kernel

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Function Documentation

void vl_homogeneouskernelmap_delete

(

VlHomogeneousKernelMap *

self

)

Parameters:

self	object. The function deletes the specified map object.

vl_homogeneouskernelmap_evaluate_d	(	VlHomogeneousKernelMap const *	self,
		double *	destination,
		vl_size	stride,
		double	x
	)

Parameters:

self	map object.
destination	output buffer.
stride	stride of the output buffer.
x	value to expand.

The function evaluates the feature map on x and stores the resulting 2*order+1 dimensional vector to destination[0], destination[stride], destination[2*stride], ....

vl_homogeneouskernelmap_evaluate_f	(	VlHomogeneousKernelMap const *	self,
		float *	destination,
		vl_size	stride,
		double	x
	)

Parameters:

self	map object.
destination	output buffer.
stride	stride of the output buffer.
x	value to expand.

The function evaluates the feature map on x and stores the resulting 2*order+1 dimensional vector to destination[0], destination[stride], destination[2*stride], ....

vl_size vl_homogeneouskernelmap_get_dimension

(

VlHomogeneousKernelMap const *

self

)

Parameters:

self

object.

Returns:

the map dimension (2 order +1).

VlHomogeneousKernelType vl_homogeneouskernelmap_get_kernel_type

(

VlHomogeneousKernelMap const *

self

)

Parameters:

self

object.

Returns:

kernel type.

vl_size vl_homogeneouskernelmap_get_order

(

VlHomogeneousKernelMap const *

self

)

Parameters:

self

object.

Returns:

the map order.

VlHomogeneousKernelMapWindowType vl_homogeneouskernelmap_get_window_type

(

VlHomogeneousKernelMap const *

self

)

Parameters:

self

object.

Returns:

window type.

VlHomogeneousKernelMap* vl_homogeneouskernelmap_new	(	VlHomogeneousKernelType	kernelType,
		double	gamma,
		vl_size	order,
		double	period,
		VlHomogeneousKernelMapWindowType	windowType
	)

Parameters:

kernelType	type of homogeneous kernel.
gamma	kernel homogeneity degree.
order	approximation order.
period	kernel period.
windowType	type of window used to truncate the kernel.

Returns:

the new homogeneous kernel map.

The function intializes a new homogeneous kernel map for the specified kernel type, homogeneity degree, approximation order, period, and truncation window. See Fundamentals for details.

The homogeneity degree gamma must be positive (the standard kernels are obtained by setting gamma to 1). When unsure, set windowType to VlHomogeneousKernelMapWindowRectangular. The period should be non-negative; specifying a negative or null value causes the function to switch to a default value.

The function returns NULL if there is not enough free memory.