grid.h File Reference

#include <ctime>
#include "Hdf.hpp"
#include "common.h"
#include "VFiles.h"

Classes
struct	grid_type_
Typedefs
typedef grid_type_	grid_type
Functions
void	create_grid (grid_type *grid, int nrows=0, int ncols=0, float64 slope=1., float64 offset=0., data_type data_fill_value=DEFAULT_DATA_FILL_VALUE, coord_type coord_fill_value=DEFAULT_COORD_FILL_VALUE, distance_type distance_fill_value=DEFAULT_DISTANCE_FILL_VALUE, time_type time_fill_value=DEFAULT_TIME_FILL_VALUE)
void	reset_grid (grid_type *grid, data_type data_fill_value, coord_type coord_fill_value, distance_type distance_fill_value, time_type time_fill_value)
void	reset_grid (grid_type *grid, data_type data_fill_value, distance_type distance_fill_value, time_type time_fill_value)
void	destroy_grid (grid_type *grid)
int	load_grid (grid_type *grid, data_type data_fill_value=DEFAULT_DATA_FILL_VALUE, coord_type coord_fill_value=DEFAULT_COORD_FILL_VALUE, distance_type distance_fill_value=DEFAULT_DISTANCE_FILL_VALUE, time_type time_fill_value=DEFAULT_TIME_FILL_VALUE)
int	save_grid (grid_type *grid, bool record_delta, bool record_latlontime)
void	copy_grid (grid_type *target_grid, grid_type *src_grid)
void	copy_grid_footprint (grid_type *target_grid, grid_type *src_grid)
bool	have_same_grid_footprint (grid_type *grid1, grid_type *grid2)

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Typedef Documentation

typedef struct grid_type_ grid_type

Grids are the main data structures handled by the software. They should have been designed as a class instead of a simple struct with functions to handle it, but by lack of time the software had to be delivered as is. A rewritten code with a grid class instead of a struct should be much clearer and easier to maintain, but will need a substantial amount of time to reimplement (and of course redocument !), that is not available today. Grids are abstracts for reprojection. Their main purpose is to handle 2-dimensional buffers of geolocated data (measures along with their latitudes, longitudes and times of acquisition). The reprojection algorithm remaps a grid of data (from one instrument product) into another one. For convenience, origin and target of the data (files and datasets) are also maintained in the structure (although this is not a very clever design, I have to confess, I hope I'll have a chance to change this if more time is given to this project)

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Function Documentation

void copy_grid (  grid_type *  target_grid, grid_type *  src_grid )

intended to copy src_grid into target_grid (does correct allocation and copies) this function is not used in the current implementation

void copy_grid_footprint (  grid_type *  target_grid, grid_type *  src_grid )

intended to copy the footprint of a grid (the footprint includes lightweight data, namely scalar fields, but not buffers) this function is not used in the current implementation

void create_grid (  grid_type *  grid, int  nrows = 0, int  ncols = 0, float64  slope = 1., float64  offset = 0., data_type  data_fill_value = DEFAULT_DATA_FILL_VALUE, coord_type  coord_fill_value = DEFAULT_COORD_FILL_VALUE, distance_type  distance_fill_value = DEFAULT_DISTANCE_FILL_VALUE, time_type  time_fill_value = DEFAULT_TIME_FILL_VALUE )

the grid constructor Parameters: grid  the address of a grid structure to initialize. All fields will be allocated (for field pointers) and initialized with the values of the subsequent parameters. nrows  the number of rows of the grid (common number of rows of all the buffers in the grid) ncols  the number of columns of the grid (common number of columns of all the buffers in the grid) slope  the initialization value for the slope field of the grid offset  the initialization value for the offset field of the grid data_fill_value  the initialization value for the grid_type::data buffer of the grid (after allocation of nrows*ncols elements) coord_fill_value  the initialization value the grid_type::lat and grid_type::lon buffers of the grid (after allocation of nrows*ncols elements) distance_fill_value  the initialization value for the grid_type::distance_from_ref buffer of the grid (after allocation of nrows*ncols elements) time_fill_value  the initialization value for the grid_type::tim and grid_type::time_from_ref buffers of the grid (after allocation of nrows*ncols elements) See also: reset_grid(grid_type *, data_type, coord_type, distance_type, time_type) cautious: create_grid currently does not initialize the grid_type::is_target field (this one had to be added to meet some user's new requirements, only after the interface of create_grid was designed. So for the time being, the grid_type::is_target field must be set directly before create_grid is called, in order to allow create_grid to allocate and initialize correctly the grid_type::src_irows and grid_type::src_icols fields. This should be fixed in a future release (this will imply to break the interface of create_grid, in order to pass the initialization value of grid_type::is_target as an argument).

void destroy_grid (  grid_type *  grid  )

the destructor of a grid it resets all the scalars fields and deallocates (and nullifies) all the pointer fields of a grid structure Parameters: grid  a pointer to the grid to destroy See also: create_grid load_grid

bool have_same_grid_footprint (  grid_type *  grid1, grid_type *  grid2 )

intended to compare two grids footprints (the footprint includes lightweight data, namely scalar fields, but not buffers) this function is not used in the current implementation

int load_grid (  grid_type *  grid, data_type  data_fill_value = DEFAULT_DATA_FILL_VALUE, coord_type  coord_fill_value = DEFAULT_COORD_FILL_VALUE, distance_type  distance_fill_value = DEFAULT_DISTANCE_FILL_VALUE, time_type  time_fill_value = DEFAULT_TIME_FILL_VALUE )

loads data from the dataset grid_type::input_dataset of the file grid_type::file into a grid. The function calls create_grid, so don't do it yourself. Grids allocated and filled by load_grid must be destroyed by the caller with destroy_grid Parameters: grid  a pointer to the grid_type structure to allocate and fill with the file data data_fill_value  the new initialization value of the grid_type::data buffer elements coord_fill_value  the new initialization value of the grid_type::lat, grid_type::lon buffer elements distance_fill_value  the new initialization value of the grid_type::distance_from_ref buffer elements time_fill_value  the new initialization value of the grid_type::tim and grid_type::time_from_ref buffer_elements See also: create_grid (called by this one) destroy_grid (to call when the grid is not used anymore)

void reset_grid (  grid_type *  grid, data_type  data_fill_value, distance_type  distance_fill_value, time_type  time_fill_value )

resets all the fields of a grid, except grid_type::lat, grid_type::lon, grid_type::tim It is used for the target grid whose geolocation fields never change. On the other hand, grid_type::data (measures), grid_type::distance_from_ref and grid_type::time_from_ref buffers must be reset with each new source grid (as source will be remapped into target). This function is essentially called from the main loop in the ::main function. Parameters: grid  the pointer to the grid to reset data_fill_value  the new initialization value of the grid_type::data buffer elements distance_fill_value  the new initialization value of the grid_type::distance_from_ref buffer elements time_fill_value  the new initialization value of the grid_type::time_from_ref buffer_elements

void reset_grid (  grid_type *  grid, data_type  data_fill_value, coord_type  coord_fill_value, distance_type  distance_fill_value, time_type  time_fill_value )

resets all the fields of a grid. It is essentially called by create_grid after allocations of pointers have been done. Parameters: grid  the pointer to the grid to reset data_fill_value  the new initialization value of the grid_type::data buffer elements coord_fill_value  the new initialization value of the grid_type::lat, grid_type::lon buffer elements distance_fill_value  the new initialization value of the grid_type::distance_from_ref buffer elements time_fill_value  the new initialization value of the grid_type::tim and grid_type::time_from_ref buffer_elements See also: create_grid

int save_grid (  grid_type *  grid, bool  record_delta, bool  record_latlontime )

saves grid_type::data buffer (with its slope and offset) into the grid_type::output_dataset of the file grid_type::file recorded in the grid structure. Parameters: grid  a pointer to the grid to save into a file record_delta  if true, saves grid_type::distance_from_ref and grid_type::time_from_ref (namely 'delta' buffers) along with the grid_type::data buffer (this parameter may be controled by a user option, see ::main) record_latlontime  if true, saves grid_type::lat, grid_type::lon and grid_type::tim buffers along with the grid_type::data buffer (this is currently only used to save latitudes, longitudes and times of acquisition of the reference grid, see ::main)

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