/Users/mdipierro/fermiqcd/development/Libraries/fermiqcd_gauge_algorithms.h File Reference

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Functions
void	set_cold (gauge_field &U)
	make a cold gauge configuration
void	set_hot (gauge_field &U)
	Make a hot gauge configuration.
void	check_unitarity (gauge_field &U, double precision=PRECISION)
	Check that gauge field is unitary within precision.
mdp_real	average_plaquette (gauge_field &U, int mu, int nu)
	Compute average plaquette on plane mu-nu.
mdp_real	average_plaquette (gauge_field &U)
	Compute average plaquette (all planes).
void	compute_em_field (gauge_field &U)
	Given a field U compute the chromo-eletro-magntic field U.em.
void	compute_long_links (gauge_field &U, gauge_field &V, int length=2)
void	set_antiperiodic_phases (gauge_field &U, int mu=0, int check=true)
mdp_matrix	project_SU (mdp_matrix M, int nstep=1)
mdp_complex	average_path (gauge_field &U, int length, int d[][2])
mdp_matrix	build_path (gauge_field &U, site x, int length, int d[][2])
void	copy_path (int length, int d[][2], int c[][2])
void	invert_path (int mu, int length, int d[][2])
void	rotate_path (int angle, int mu, int nu, int length, int d[][2])

---

Detailed Description

Version:

2009-12-21

Author:

Massimo Di Pierro <mdipierro@cs.depaul.edu>

Various stuff for gauge field

Distributed under GPL2 License

Created with support from the US Department of Energy

---

Function Documentation

mdp_complex average_path	(	gauge_field &	U,
		int	length,
		int	d[][2]
	)

Takes a field U and path d of length and compute the average of the path on the entire lattice. Assumes computation can be done locally for each site

Example:

///   int mu=0, nu=1;
///   gauge_field U(lattice,nc);
///   int d[][2]={{+1,mu},{+1,nu},{-1,mu},{-1,nu}}
///   mdp << "plaquette=" << average_path(U,4,d) << endl;
/// 

mdp_real average_plaquette

(

gauge_field &

U

)

Compute average plaquette (all planes).

mdp_real average_plaquette	(	gauge_field &	U,
		int	mu,
		int	nu
	)

Compute average plaquette on plane mu-nu.

mdp_matrix build_path	(	gauge_field &	U,
		site	x,
		int	length,
		int	d[][2]
	)

Takes a field U, a site x, a path d of length and compute the product of links amdp_int the path starting at x. Assumes computation can be done locally for each site

Example:

///   int mu=0, nu=1;
///   gauge_field U(lattice,nc);
///   int d[][2]={{+1,mu},{+1,nu},{-1,mu},{-1,nu}}
///   forallsites(x)
///      cout << "plaquette(x)=" << average_path(U,x,4,d) << endl;
/// 

void check_unitarity	(	gauge_field &	U,
		double	precision = PRECISION
	)

Check that gauge field is unitary within precision.

void compute_em_field

(

gauge_field &

U

)

Given a field U compute the chromo-eletro-magntic field U.em.

void compute_long_links	(	gauge_field &	U,
		gauge_field &	V,
		int	length = 2
	)

For use with asqtad staggered action Given field V makes a field U.long_links where (if length==2)

/// U.long_links(x,mu)=V(x,mu)*V(x+mu,mu);
/// 

or (if length==3)

/// U.long_links(x,mu)=V(x,mu)*V(x+mu,mu)*V((x+mu)+mu,mu);
/// 

void copy_path	(	int	length,
		int	d[][2],
		int	c[][2]
	)

void invert_path	(	int	mu,
		int	length,
		int	d[][2]
	)

mdp_matrix project_SU	(	mdp_matrix	M,
		int	nstep = 1
	)

takes a matrix M, performs a Cabibbo-Marinari cooling and returns the projected matrix

void rotate_path	(	int	angle,
		int	mu,
		int	nu,
		int	length,
		int	d[][2]
	)

void set_antiperiodic_phases	(	gauge_field &	U,
		int	mu = 0,
		int	check = true
	)

To set antiperiodic boundary conditions on in direction mu

///    gauge_field U(lattice,nc);
///    // do heatbath on U
///    set_antiperiodic_phases(U,mu,true);
///    // use quarks (will have antiperiodic boundary conditions)
///    set_antiperiodic_phases(U,mu,false);
/// 

void set_cold

(

gauge_field &

U

)

make a cold gauge configuration

void set_hot

(

gauge_field &

U

)

Make a hot gauge configuration.