input_data.c File Reference

Provide basic functionality for reading input data files. More...

#include "pluto.h"

Functions
void	InputDataSet (char *grid_fname, int *get_var)
void	InputDataRead (char *data_fname)
void	InputDataInterpolate (double *vs, double x1, double x2, double x3)
void	InputDataFree (void)

Variables
static int	id_nvar
static int	id_var_indx [256]
static int	id_nx1
static int	id_nx2
static int	id_nx3
static int	id_geom
static double *	id_x1
static double *	id_x2
static double *	id_x3
static double ***	Vin [256]

Detailed Description

Collects a number of functions for opening, reading and assigning initial conditions from user-supplied data file(s). The geometry and dimensions of the input grid can be different from the actual grid employed by PLUTO, as long as the coordinate geometry transformation has been implemented. The input grid and data files should employ the same format and conventions employed by PLUTO.

• Gridfile: coordinates should be written using the PLUTO 4.0 grid format.

• Datafile: variables should be written in sequence in a single binary file using single or double precision. The file extension must be ".flt" or ".dbl" for the former and the latter, respectively.

  Note that not all of the variables should be present and the input array ::get_var specifies which one are to be searched for.

The InputDataSet() initialize the module and by assigning values to global variables such as size, geometry and dimensions of the input grid. Data values are read through the function InputDataRead() while InputDataInterpolate() can be finally used to map input data onto the grid employed by PLUTO using bi- or tri-linear interpolation to fill the data array at the desired coordinate location.

Authors

A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)
P. Tzeferacos

Date

Aug 27, 2012

Function Documentation

void InputDataFree

(

void

)

Free memory stored by user-supplied data.

void InputDataInterpolate	(	double *	vs,
		double	x1,
		double	x2,
		double	x3
	)

Perform bi- or tri-linear interpolation on external dataset to compute vs[] at the given point {x1,x2,x3}.

Parameters

[in]	vs	interpolated value
[in]	x1	coordinate point at which at interpolates are desired
[in]	x2	coordinate point at which at interpolates are desired
[in]	x3	coordinate point at which at interpolates are desired

Returns

This function has no return value.

The function performs the following tasks.

• Convert PLUTO coordinates to input grid geometry if necessary.

• Make sure point (x1,x2,x3) does not fall outside input grid range. Limit to input grid edge otherwise.

• Use table lookup by binary search to find the indices il, jl and kl such that grid points of PLUTO fall between [il, il+1], [jl, jl+1], [kl, kl+1].

• Define normalized coordinates between [0,1]:
  • x[il+1] < x1[i] < x[il+1] ==> 0 < xx < 1
  • y[jl+1] < x2[j] < y[jl+1] ==> 0 < yy < 1
  • z[kl+1] < x3[k] < z[kl+1] ==> 0 < zz < 1

• Perform bi- or tri-linear interpolation.

void InputDataRead

(

char *

data_fname

)

Read input data file and store the contents into the local storage array Vin. Memory allocation is also done here. The grid size and number of variables must have previously set by calling InputDataSet().

Parameters

[in]

data_fname

the data file name

Returns

This function has no return value.

void InputDataSet	(	char *	grid_fname,
		int *	get_var
	)

Initialize access to input data file by assigning values to grid-related information (geometry, number of points, etc...). This function should be called just once for input-data initialization.

Parameters

[in]	gname	the grid file name
[in]	get_var	an array of integers specifying which variables have to be read from the input data.

Returns

Thi function has no return value.

The following tasks are performed.

• Scan grid data file and try to determine the grid geometry (id_geom). Search for tag "GEOMETRY:" and read the word that follows.

• Move file pointer until the first line that does not begin with a "#".

• Start reading number of points and grid coordinates. For the input x1 direction these are stored inside the module variables id_nx1 and id_x1.

• Find out how many and which variables we have to read (:id_nvar and id_var_indx). Stop counting variables as soon as the first occurrence of "-1" in get_var is encountered

Variable Documentation

int id_geom

static

Geometry of the input grid.

int id_nvar

static

Number of variables to be read on input.

int id_nx1

static

Size of input grid in the x1 direction.

int id_nx2

static

Size of input grid in the x2 direction.

int id_nx3

static

Size of input grid in the x3 direction.

int id_var_indx[256]

static

The variable index.

double* id_x1

static

Array of point coordinates of the x1 input grid.

double* id_x2

static

Array of point coordinates of the x2 input grid.

double* id_x3

static

Array of point coordinates of the x3 input grid.

double*** Vin[256]

static

An array of 3D data values containing the initial data file variables.