common Namespace Reference

common function shared by many program More...

Functions
int	min_wt_decoding (itpp::GF2mat C)
int	min_wt_decoding (itpp::GF2mat C, itpp::GF2mat G)
int	save_dist (int d, char *filename)
int	rand_dist (itpp::GF2mat C, int perm_try=10)
int	classical_dist (itpp::GF2mat G)
itpp::GF2mat	nullSpace (itpp::GF2mat G)
itpp::GF2mat	getC (itpp::GF2mat G_x, itpp::GF2mat G_z, int flip=0)
int	quantum_dist_v2 (itpp::GF2mat G_x, itpp::GF2mat G_z, int flip=0)
int	quantum_dist (itpp::GF2mat G_x, itpp::GF2mat G_z, int dist_expected, int debug, int flip=0)
int	hypergraph_dist (itpp::GF2mat Aj, itpp::GF2mat Ajplus, int dist_expected, int flip=0)
int	draw_toric_x_error (itpp::bvec error_bits)
int	draw_toric_x_error (itpp::bvec error_bits, std::string header)
itpp::bvec	find_error (itpp::bvec e_in, itpp::GF2mat H)
itpp::GF2mat	get_check_code734 (int L)
itpp::GF2mat	get_check_code743 (int L)
itpp::GF2mat	get_check_rept (int L)
itpp::GF2mat	get_check (int generator_flag, int L)
itpp::LDPC_Code	GF2mat_to_LDPC_Code (itpp::GF2mat G)
itpp::LDPC_Code	MM_to_LDPC_Code (char *filename)
std::string	color_text (std::string str)
std::string	red_text (std::string str)
std::string	blue_text (std::string str)
int	get_time (int mode=1)
bool	is_quantum_code (itpp::GF2mat &G_x, itpp::GF2mat &G_z)
bool	is_quantum_code (itpp::GF2mat &Gx, itpp::GF2mat &Gz, itpp::GF2mat &Cx, itpp::GF2mat &Cz)
itpp::GF2mat	make_it_full_rank (itpp::GF2mat fat)
int	GF2matPrint (itpp::GF2mat &G, std::string name)
int	matPrint (itpp::mat G, char *name=(char *) " ")
itpp::GF2mat	kron (itpp::GF2mat A, itpp::GF2mat B)
std::string	NumberToString (int pNumber)
itpp::GF2mat	append_vector (itpp::GF2mat G, itpp::bvec b)
itpp::GF2mat	get_GF2mat (char *filename_prefix, char *filename_suffix)
itpp::GF2mat	get_GF2mat (char *parent_folder, char *folder, char *filename)
double	get_error_density (itpp::GF2mat E)
int	mat2gnudata (itpp::mat data, std::string filename, std::string header)

Variables
const int	INF =999

Detailed Description

common function shared by many program

Function Documentation

append_vector()

itpp::GF2mat common::append_vector	(	itpp::GF2mat	G,
		itpp::bvec	b
	)

< append row vectors to an itpp::GF2mat

Warning

This is super ineffcient, and should not be used this way

Definition at line 202 of file lib.cpp.

blue_text()

std::string common::blue_text

(

std::string

str

)

return blue std::string

Definition at line 42 of file lib.cpp.

classical_dist()

int common::classical_dist

(

itpp::GF2mat

G

)

use random window decoder to find distance of a classical code with parity check patrix G

Parameters

G	parity check matrix \(GC^T=0\) min_wt_decoding is used when C.rows()<7 perm_try=10 always. No interface is given to change it yet.

Definition at line 114 of file dist.cpp.

color_text()

std::string common::color_text

(

std::string

str

)

return text in red color for printing

currently return red color as default; more color to be implemented

	foreground	background
black	30	40
red	31	41
green	32	42
yellow	33	43
blue	34	44
magenta	35	45
cyan	36	46
white	37	47

Definition at line 32 of file lib.cpp.

draw_toric_x_error() [1/2]

int common::draw_toric_x_error

(

itpp::bvec

error_bits

)

draw the lattice, with error bond in red

Definition at line 389 of file dist.cpp.

draw_toric_x_error() [2/2]

int common::draw_toric_x_error	(	itpp::bvec	error_bits,
		std::string	header
	)

a wrapper of draw_toric_x_error, with an extra header

Definition at line 439 of file dist.cpp.

find_error()

itpp::bvec common::find_error	(	itpp::bvec	e_in,
		itpp::GF2mat	H
	)

find error with same syndrome for a classical code, can be used for CSS codes as well

Parameters

e_in	original error
H	parity check matrix

Returns

an error with same syndrome (It is not necessarily an equivalent error) for principle, see random window decoder

Definition at line 446 of file dist.cpp.

get_check()

itpp::GF2mat common::get_check	(	int	generator_flag,
		int	L
	)

return check matrix

Parameters

L	size of the code switch(generator_flag){ case 1: return get_check_rept(L);break; case 2: return get_check_code734(L);break; case 3: return get_check_code743(L);break;

Definition at line 524 of file dist.cpp.

get_check_code734()

itpp::GF2mat common::get_check_code734

(

int

L

)

return check matrix code code [7,3,4], find definition in research note.pdf

Parameters

L	size of the code, must be a multiple of 7

Definition at line 471 of file dist.cpp.

get_check_code743()

itpp::GF2mat common::get_check_code743

(

int

L

)

return check matrix code code [7,4,3], find definition in research note.pdf

Parameters

L	size of the code, must be a multiple of 7

Definition at line 490 of file dist.cpp.

get_check_rept()

itpp::GF2mat common::get_check_rept

(

int

L

)

return circulant check matrix for repetition code of length L

Definition at line 513 of file dist.cpp.

get_error_density()

double common::get_error_density

(

itpp::GF2mat

E

)

return density of a matrix whose first row is zero remove first row and return density of the remained submatrix

Definition at line 224 of file lib.cpp.

get_GF2mat() [1/2]

itpp::GF2mat common::get_GF2mat	(	char *	filename_prefix,
		char *	filename_suffix
	)

getitpp::GF2mat from filename with given pattern full name = filename_prefix+filename_suffix

Definition at line 210 of file lib.cpp.

get_GF2mat() [2/2]

itpp::GF2mat common::get_GF2mat	(	char *	parent_folder,
		char *	folder,
		char *	filename
	)

getitpp::GF2mat from filename with given pattern full name = parent_folder/folder/filename

Definition at line 217 of file lib.cpp.

get_time()

int common::get_time

(

int

mode = 1

)

return time in secs, milliseconds, or ...

Parameters

mode=1	secs (default)
mode=2	millisecs, \( 10 ^{-3} \)
mode=3	10 nano secs = \(10^{-8}\) sec

Definition at line 53 of file lib.cpp.

getC()

itpp::GF2mat common::getC	(	itpp::GF2mat	G_x,
		itpp::GF2mat	G_z,
		int	flip = 0
	)

get codeword generating matrix for CSS codes

Parameters

G_x	X type party check matrix
G_z	Z type party check matrix
flip=0	whether flipping or nor

Returns

C_x when flip=0

C_z when flip=1

Definition at line 143 of file dist.cpp.

GF2mat_to_LDPC_Code()

itpp::LDPC_Code common::GF2mat_to_LDPC_Code

(

itpp::GF2mat

G

)

Definition at line 550 of file dist.cpp.

GF2matPrint()

int common::GF2matPrint	(	itpp::GF2mat &	G,
		std::string	name
	)

print brief information of G: name, size, density

Parameters

G
name	name of the matrix

Definition at line 144 of file lib.cpp.

hypergraph_dist()

int common::hypergraph_dist	(	itpp::GF2mat	Aj,
		itpp::GF2mat	Ajplus,
		int	dist_expected,
		int	flip = 0
	)

get estimated distance of a CSS code generated from a chain complex \( A_jA_{j+1}=0 \)

Parameters

Aj
Ajplus
dist_expected	use expected distance to control number of trials
flip=0	(default) or 1, flip left and right if flip=1

Returns

left distance of CSS code (Aj,Ajplus^T)

left distance of (Aj,Ajplus^T), right distance of (G_x,G_z), flip left and right if flip = 1, TODO::This should be implemented as a wrapper of quantum_dist()

Definition at line 292 of file dist.cpp.

is_quantum_code() [1/2]

bool common::is_quantum_code	(	itpp::GF2mat &	G_x,
		itpp::GF2mat &	G_z
	)

check if it is a quantum CSS code

Parameters

G_x	X type parity check matrix
G_z	Z type parity check matrix

Definition at line 77 of file lib.cpp.

is_quantum_code() [2/2]

bool common::is_quantum_code	(	itpp::GF2mat &	Gx,
		itpp::GF2mat &	Gz,
		itpp::GF2mat &	Cx,
		itpp::GF2mat &	Cz
	)

check if it is a quantum CSS code

Parameters

G_x	X type parity check matrix
G_z	Z type parity check matrix
C_x	X type codeword generating matrix
C_z	Z type codeword generating matrix

Definition at line 91 of file lib.cpp.

kron()

itpp::GF2mat common::kron	(	itpp::GF2mat	A,
		itpp::GF2mat	B
	)

Kronecker product of A and B

Parameters

A	the outer matrix
B	the inner matrix

Warning

: The implementation is confusing, but should works as the conventional Kronecker product defined in the wikipedia page

Definition at line 162 of file lib.cpp.

make_it_full_rank()

itpp::GF2mat common::make_it_full_rank

(

itpp::GF2mat

fat

)

reduce a fat matrix with degenerate rows to a thin matrix with full rank; remove the dependent rows

Parameters

fat	a GF2mat not necessary full rank

Returns

thin: a full rank GF2mat matrix

Definition at line 123 of file lib.cpp.

mat2gnudata()

int common::mat2gnudata	(	itpp::mat	data,
		std::string	filename,
		std::string	header
	)

save mat into gnuplot data file, with a custom comment as header

Definition at line 237 of file lib.cpp.

matPrint()

int common::matPrint	(	itpp::mat	G,
		char *	name = (char *) " "
	)

print brief information of G: name, size, density

Parameters

G
name	name of the matrix

should change char to string

Definition at line 153 of file lib.cpp.

min_wt_decoding() [1/2]

int common::min_wt_decoding

(

itpp::GF2mat

C

)

min weight decoder for classical code

Parameters

C	codeword generating matrix

Returns

min weight of all codewords (any combination of rows in the generating matrix)

Definition at line 12 of file dist.cpp.

min_wt_decoding() [2/2]

int common::min_wt_decoding	(	itpp::GF2mat	C,
		itpp::GF2mat	G
	)

min weight decoder for CSS code distance The distance between \( y=ax^2+b \)

Parameters

C	codeword generating matrix
G	gauge matrix

Returns

\( d_{\text{min}} = \text{min}_{\alpha \neq 0, \beta} \text{wgt} (\alpha C+ \beta G), \alpha \neq 0 \)

Definition at line 44 of file dist.cpp.

MM_to_LDPC_Code()

itpp::LDPC_Code common::MM_to_LDPC_Code

(

char *

filename

)

convert GF2mat saved in .mm file to LDPC_Code

Definition at line 559 of file dist.cpp.

nullSpace()

itpp::GF2mat common::nullSpace

(

itpp::GF2mat

G

)

Returns

H such that \(GH^T = 0\), and rank G + rank H = n = full rank

Definition at line 133 of file dist.cpp.

NumberToString()

std::string common::NumberToString

(

int

pNumber

)

convert int to string

Warning

not used anywhere, should be replaced by build-in function to_string()

Definition at line 195 of file lib.cpp.

quantum_dist()

int common::quantum_dist	(	itpp::GF2mat	G_x,
		itpp::GF2mat	G_z,
		int	dist_expected,
		int	debug,
		int	flip = 0
	)

get estimated distance for CSS codes

Parameters

G_x	X type party check matrix
G_z	Z type party check matrix
flip=0	whether flipping or nor
dist_expected	use expected distance to control number of trials

Returns

d_x when flip=0

d_z when flip=1

Definition at line 228 of file dist.cpp.

quantum_dist_v2()

int common::quantum_dist_v2	(	itpp::GF2mat	G_x,
		itpp::GF2mat	G_z,
		int	flip = 0
	)

get estimated distance for CSS codes

Parameters

G_x	X type party check matrix
G_z	Z type party check matrix
flip=0	whether flipping or nor

Returns

d_x when flip=0

d_z when flip=1

Definition at line 179 of file dist.cpp.

rand_dist()

int common::rand_dist	(	itpp::GF2mat	C,
		int	perm_try = 10
	)

use random window decoder to find min wt of rows in C. min_wt_decoding is used when C.rows()<7

Parameters

C	codeword generating matrix
perm_try=10	number of random trials

Definition at line 82 of file dist.cpp.

red_text()

std::string common::red_text

(

std::string

str

)

return red std::string

Definition at line 37 of file lib.cpp.

save_dist()

int common::save_dist	(	int	d,
		char *	filename
	)

save distance to a file, as a single-element itpp::mat

Definition at line 73 of file dist.cpp.

Variable Documentation

INF

const int common::INF =999

Infinite distance in random window decoder

Definition at line 19 of file dist.h.