helperfunc.h File Reference

header file for helper functions More...

#include <string>
#include <vector>
#include "Matrix.h"
#include "Cvals.h"

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Classes
struct	array_data
Defines
#define	M_PI   3.1415926535897932385
Functions
void *	alloc_1d_array (int size, int type)
struct array_data	alloc_mem (int dimension, int type,...)
void *	shift_pointer (void *pointer, int type, int num)
void	set_pointer_pointer_val (void *pointer, int type, void *val)
void *	get_pointer_pointer_val (void *pointer, int type)
void	print_alloc_data (struct array_data arr)
void	check_pointer_sanity (void *pointer, const char *func)
void	print_pointer_val (void *pointer, int type)
void	free_mem (struct array_data arr)
int	gridder (int nx, int ny, int ndata, int offset[3], int jump[3], double xmin, double xmax, double ymin, double ymax, float *xval, float *yval, float *val, float *xsep, float *ysep, float **results)
int	gridder (int nx, int ny, int ndata, int offset[3], int jump[3], double xmin, double xmax, double ymin, double ymax, float *xval, float *yval, float *val, vector< float > &xsep, vector< float > &ysep, Matrix< float > &results, Matrix< int > &number)
int	gridder (int nx, int ny, int ilow, int ihigh, double xmin, double xmax, double ymin, double ymax, Cvals *xval, Cvals *yval, Cvals *val, vector< float > &xsep, vector< float > &ysep, Matrix< float > &results, Matrix< int > &number)
double	get_upbnd_bin_linear (int nbins, double xmin, double xmax, int bin)
double	get_lowbnd_bin_linear (int nbins, double xmin, double xmax, int bin)
int	get_bin_number_linear (int nbins, double xmin, double xmax, double xval)
double	get_center_bin_linear (int nbins, double xmin, double xmax, int bin)
float *	al1df (int nval)
void	fr1df (float *pointer)
float **	al2df (int nrow, int ncol)
void	fr2df (float **pointer, int ncol)
void	flhunt (float *xx, int n, float x, int *jlo)
void	flhunt (vector< float > xx, int n, float x, int *jlo)
void	convolve_2d_standard (std::string type, Matrix< float > &matrix, vector< float > xvals, vector< float > yvals, std::vector< double > parameters)
void	convolve_2d_standard_gaussian (float *array, int nrow, int ncol, const vector< float > &xvals, const vector< float > &yvals, double xsigma, double ysigma, const double &gauss_cut)
void	convolve_2d_standard_gaussian (Matrix< float > &matrix, const vector< float > &xvals, const vector< float > &yvals, double xsigma, double ysigma, const double &gauss_cut=0.)
void	convolve_2d_standard_gaussian_row (unsigned n, Matrix< float > &matrix, Matrix< float > &temp, const vector< float > &xvals, const vector< float > &yvals, double xsigma, double ysigma, const int &xcut, const int &ycut)
void	convolve_2d_standard_gaussian_point (unsigned n, unsigned m, Matrix< float > &matrix, Matrix< float > &temp, const vector< float > &xvals, const vector< float > &yvals, double xsigma, double ysigma, const int &xcut, const int &ycut)
void	convolve_2d_standard_gaussian_varsig (unsigned n, unsigned m, Matrix< float > &matrix, Matrix< float > &temp, const Matrix< float > &xsig, const Matrix< float > &ysig, const vector< float > &xvals, const vector< float > &yvals)
void	test_convolution (void)

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Detailed Description

header file for helper functions

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Function Documentation

float* al1df

(

int

nval

)

1D float array functions

Allocate a 1-dimensional float array of nval spaces. Returns a pointer to the array. On error: prints a warning and shuts down the program ^^

float** al2df	(	int	nrow,
		int	ncol
	)

2D float array functions

Allocate a 2-dimensional float array of nval spaces. Returns a pointer to the array. No effort is done to keep the memory (the rows) consecutive in memory.

On error: prints a warning and shuts down the program ^^

void* alloc_1d_array	(	int	size,
		int	type
	)

function to allocate a 1-D array

Parameters:

	size	size of the array
	type	type of the array: negative number: pointer to this type (e.g. -1: type *int) 1 : int 2 : float 3 : double 4 : char

struct array_data alloc_mem	(	int	dimension,
		int	type,
			...
	)			[read]

This is the mother routine, should be used for all allocating. The arguments:

Parameters:

	dimension	the dimension of the array (e.g. an array[][][]: dimension 3)
	type	type of the array. This is an integer. For a list of the types: see alloc_1D_array
	...	list of the sizes of each individual dimension.

Eample: to allocate an integer 4x5x2 array: alloc_mem(3, 1, 4,5,2); The resulting struct can then be used as: (e.g. struct array_data tmp): ((double ***)tmp.arr)[0][1][2]

note: memory is not allocated consecutive in the memory, e.g. the rows of the allocated array do not necessarily form 1 block in the memory (a row by itself is consecutive of course).

void check_pointer_sanity	(	void *	pointer,
		const char *	func
	)

check if the pointer is zero

void convolve_2d_standard_gaussian	(	Matrix< float > &	matrix,
		const vector< float > &	xvals,
		const vector< float > &	yvals,
		double	xsigma,
		double	ysigma,
		const double &	gauss_cut
	)

gauss_cut set this value if no smoothing is to be done when the value of the gaussian drops below this value. This limits the smoothing of a point to an area around this point instead of smoothing to the entire region. Note: it is set to zero as default i.e. smooth over entire region

*** Works only on a grid with equal x-spacing everywhere, also equal *** y-spacing everywhere (e.g. xvals[i]-xvals[i-1] is constant).

convolving a 2D grid with a 2D gaussian: consists of the discrete sum over the indices, multiplying the values of the grid with the values of the respective integrals of the 2D gaussian functions over the grid cell. We thus seem to be dealing with a discrete convolution, that is only because the integrals (from our continuous convolution) reduce to integrating the error function in the cells and then adding results from the entire domain.

This function first constructs a 2D grid of the integrated gaussian function. This grid is for x>0 and y>0. The leftmost column grid-cells are (xvals[i]-xvals[i-1])/2. wide, same for the y-width of the bottom row. This because the origin of this grid (0,0) should ly in the middle of a grid cell. We then multiply the gaussian integral for all the edge cells by 2, for the origin cell by 4. These edge cells thus ly half in x>0,y>0 and half in either x>0,y<0 or x<0,y>0. The origin cell lies in all 4 regions.

After the grid is constructed (using the error function for integration, and subtracting cells from each-other to get the integral in a cell) each cell of the input matrix is convolved with this gaussian grid.

void convolve_2d_standard_gaussian	(	float *	array,
		int	nrow,
		int	ncol,
		const vector< float > &	xvals,
		const vector< float > &	yvals,
		double	xsigma,
		double	ysigma,
		const double &	gauss_cut
	)

overloaded version that is able to operate on a pointer. Should never use this unless you are really stuck with float pointers, use the one with the matrix instead.

void flhunt	(	vector< float >	xx,
		int	n,
		float	x,
		int *	jlo
	)

vector version Given an array xx[0..n-1], and given a value x, returns a value jlo such that x is between xx[jlo] and xx[jlo+1]. xx[0..n-1] must be monotonic, either increasing or decreasing. jlo=-1 or jlo=n-1 is returned to indicate that x is out of range. jlo on input is taken as the initial guess for jlo on output.

used to be a nr function, replaced because of the licencing

void flhunt	(	float *	xx,
		int	n,
		float	x,
		int *	jlo
	)

float version Given an array xx[0..n-1], and given a value x, returns a value jlo such that x is between xx[jlo] and xx[jlo+1]. xx[0..n-1] must be monotonic, either increasing or decreasing. jlo=-1 or jlo=n-1 is returned to indicate that x is out of range. jlo on input is taken as the initial guess for jlo on output.

void free_mem

(

struct array_data

arr

)

Use this routine to free the memory previously allocated by alloc_mem

int get_bin_number_linear	(	int	nbins,
		double	xmin,
		double	xmax,
		double	xval
	)

return the bin number for an xvalue between xmin and xmax, with nbins bins. the scale is linear. A value of xmin returns 0, a value of xmax returns nbins - 1. (xmax would normally return nbins but is modified by hand to avoid segfaults)

double get_center_bin_linear	(	int	nbins,
		double	xmin,
		double	xmax,
		int	bin
	)

returns the center value of a bin. bins: between 0 and nbins-1

void* get_pointer_pointer_val	(	void *	pointer,
		int	type
	)

assuming "pointer" is a pointer to a pointer, get the value of this last pointer

int gridder	(	int	nx,
		int	ny,
		int	ndata,
		int	offset[3],
		int	jump[3],
		double	xmin,
		double	xmax,
		double	ymin,
		double	ymax,
		float *	xval,
		float *	yval,
		float *	val,
		vector< float > &	xsep,
		vector< float > &	ysep,
		Matrix< float > &	results,
		Matrix< int > &	number
	)

overloaded: uses a Matrix for the results. See the file info for details. ilow, ihigh: loop over the particle numbers [ilow, ihigh[

int gridder	(	int	nx,
		int	ny,
		int	ndata,
		int	offset[3],
		int	jump[3],
		double	xmin,
		double	xmax,
		double	ymin,
		double	ymax,
		float *	xval,
		float *	yval,
		float *	val,
		float *	xsep,
		float *	ysep,
		float **	results
	)

Allows you to distribute any quantity you want to a 2D grid

void print_alloc_data

(

struct array_data

arr

)

use this routine to print information about an allocated array_data struct: information about the dimension, column sizes, adresses of the array locations and the actual values stored in the array

void print_pointer_val	(	void *	pointer,
		int	type
	)

assuming pointer is a pointer to a variable, print the value of this variable

void set_pointer_pointer_val	(	void *	pointer,
		int	type,
		void *	val
	)

Set the value of the pointer to which the argument pointer points (that's a lot of pointers in one sentence :D)

void* shift_pointer	(	void *	pointer,
		int	type,
		int	num
	)

shift a pointer of type "type" num spaces