seq Class Reference

seq is used to create sequences for indexing af::array More...

#include <seq.h>

Public Member Functions
	seq (double length=0)
	Creates a sequence of size length as [0, 1, 2..., length - 1]. More...
	~seq ()
	Destructor. More...
	seq (double begin, double end, double step=1)
	Creates a sequence starting at begin, ending at or before end (inclusive) with increments as step. More...
	seq (seq other, bool is_gfor)
	Copy constructor. More...
	seq (const af_seq &s_)
	Create a seq object from an af_seq struct. More...
seq &	operator= (const af_seq &s)
	Assignment operator to create a new sequence from an af_seq. More...
seq	operator- ()
	Negation operator creates a sequence with the signs negated. More...
seq	operator+ (double x)
	Addition operator offsets the begin and end by x. More...
seq	operator- (double x)
	Subtraction operator offsets the begin and end by x. More...
seq	operator* (double x)
	Multiplication operator spaces the sequence by a factor x. More...
	operator array () const
	Implicit conversion operator from seq to af::array. More...

Data Fields
af_seq	s
	Get the af_seq C-style struct. More...
size_t	size
	Get's the length of the sequence. More...
bool	m_gfor
	Flag for gfor. More...

Friends
seq	operator+ (double x, seq y)
seq	operator- (double x, seq y)
seq	operator* (double x, seq y)

Detailed Description

seq is used to create sequences for indexing af::array

Examples

computer_vision/fast.cpp, computer_vision/harris.cpp, computer_vision/matching.cpp, computer_vision/susan.cpp, getting_started/rainfall.cpp, getting_started/vectorize.cpp, graphics/field.cpp, graphics/gravity_sim.cpp, graphics/plot2d.cpp, graphics/plot3.cpp, helloworld/helloworld.cpp, image_processing/binary_thresholding.cpp, image_processing/confidence_connected_components.cpp, image_processing/filters.cpp, image_processing/image_editing.cpp, image_processing/morphing.cpp, image_processing/pyramids.cpp, lin_algebra/svd.cpp, machine_learning/bagging.cpp, machine_learning/deep_belief_net.cpp, machine_learning/geneticalgorithm.cpp, machine_learning/kmeans.cpp, machine_learning/neural_network.cpp, and machine_learning/rbm.cpp.

Definition at line 45 of file seq.h.

Constructor & Destructor Documentation

seq() [1/4]

seq

(

double

length = 0

)

Creates a sequence of size length as [0, 1, 2..., length - 1].

The sequence has begin as 0, end as length - 1 and step as 1.

Note

When doing seq(-n), where n is > 0, then the sequence is generated as 0...-n but step remains +1. This is because when such a sequence is used for indexing af::array, then -n represents n elements from the end. That is, seq(-2) will imply indexing an array 0...dimSize - 2.

                    // [begin, end, step]
seq a(10);          // [0, 9, 1]    => 0, 1, 2....9

Parameters

[in]

length

is the size of the seq to be created.

~seq()

~seq

(

)

Destructor.

seq() [2/4]

seq	(	double	begin,
		double	end,
		double	step = 1
	)

Creates a sequence starting at begin, ending at or before end (inclusive) with increments as step.

The sequence will be [begin, begin + step, begin + 2 * step...., begin + n * step] where the begin + n * step <= end.

                    // [begin, end, step]
seq a(10, 20);      // [10, 20, 1]  => 10, 11, 12....20
seq b(10, 20, 2);   // [10, 20, 2]  => 10, 12, 14....20
seq c(-5, 5);       // [-5, 5, 1]   => -5, -4, -3....0, 1....5
seq d(-5, -15, -1); // [-5,-15, -1] => -5, -6, -7....-15
seq e(-15, -5, 1);  // [-15, -5, 1] => -15, -14, -13....-5

Parameters

[in]	begin	is the start of the sequence
[in]	end	is the maximum value a sequence can take (inclusive)
[in]	step	is the increment or decrement size (default is 1)

seq() [3/4]

seq	(	seq	other,
		bool	is_gfor
	)

Copy constructor.

Creates a copy seq from another sequence.

Parameters

[in]	other	seqence to be copies
[in]	is_gfor	is the gfor flag

seq() [4/4]

seq

(

const af_seq &

s_

)

Create a seq object from an af_seq struct.

Parameters

[in]

s_

is the af_seq struct

Member Function Documentation

operator array()

operator array

(

)

const

Implicit conversion operator from seq to af::array.

Convertes a seq object into an af::array object. The contents of the af:array will be the explicit values from the seq.

Note

Do not use this to create arrays of sequences. Use range.

                    // [begin, end, step]
seq s(10, 20, 2);   // [10, 20, 2] => 10, 12, 14....20
array arr = s;
af_print(arr);      // 10    12    14    16    18    20

operator*()

seq operator* ( double  x )

inline

Multiplication operator spaces the sequence by a factor x.

begin is changed to begin * x end is changed to end * x step is changed to step * x

                    // [begin, end, step]
seq a(10, 20, 2);   // [10, 20, 2] => 10, 12, 14....20
seq b(-5, 5);       // [-5, 5, 1] => -5, -4, -3....0, 1....5
seq c = a * 3;      // [30, 60, 6] => 30, 36, 42....60
seq d = b * 3;      // [-15, 15, 3] => -15, -12, -9....0, 3....15
seq e = a * 0.5;    // [5, 10, 1] => 5, 6, 7....10

Definition at line 199 of file seq.h.

{ return seq(s.begin * x, s.end * x, s.step * x); }

operator+()

seq operator+ ( double  x )

inline

Addition operator offsets the begin and end by x.

There is no change in step.

begin is changed to begin + x end is changed to end + x

                    // [begin, end, step]
seq a(2, 20, 2);    // [2, 20, 2] => 2, 4, 6....20
seq b = a + 3;      // [5, 23, 2] => 5, 7, 9....23

Definition at line 164 of file seq.h.

{ return seq(s.begin + x, s.end + x, s.step); }

operator-() [1/2]

seq operator- ( )

inline

Negation operator creates a sequence with the signs negated.

begin is changed to -begin end is changed to -end step is changed to -step

                // [begin, end, step]
seq a(1, 10);   // [ 1, 10, 1] => 1, 2, 3....10
seq b = -a;     // [-1,-10,-1] => -1, -2, -3...-10

Definition at line 149 of file seq.h.

{ return seq(-s.begin, -s.end,  -s.step); }

operator-() [2/2]

seq operator- ( double  x )

inline

Subtraction operator offsets the begin and end by x.

There is no change in step.

begin is changed to begin - x end is changed to end - x

                    // [begin, end, step]
seq a(10, 20, 2);   // [10, 20, 2] => 10, 12, 14....20
seq b(2, 10);       // [ 2, 10, 1] => 2, 3, 4....10
seq c = a - 3;      // [ 7, 17, 2] => 7, 9, 11....17
seq d = b - 3;      // [-1,  7, 2] => -1, 1, 3....7

Definition at line 181 of file seq.h.

{ return seq(s.begin - x, s.end - x, s.step); }

operator=()

seq & operator=

(

const af_seq &

s

)

Assignment operator to create a new sequence from an af_seq.

This operator creates a new sequence using the begin, end and step from the input sequence.

Parameters

[in]

s

is the input sequence

Friends And Related Function Documentation

operator*

seq operator* ( double  x, seq  y  )

friend

Definition at line 205 of file seq.h.

{ return  y * x; }

operator+

seq operator+ ( double  x, seq  y  )

friend

Definition at line 201 of file seq.h.

{ return  y + x; }

operator-

seq operator- ( double  x, seq  y  )

friend

Definition at line 203 of file seq.h.

{ return -y + x; }

Field Documentation

m_gfor

bool m_gfor

Flag for gfor.

Definition at line 61 of file seq.h.

s

af_seq s

Get the af_seq C-style struct.

Definition at line 51 of file seq.h.

size

size_t size

Get's the length of the sequence.

Definition at line 56 of file seq.h.

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The documentation for this class was generated from the following file:

• seq.h