Dataset

---

Detailed Description

A dataset is a container of astro objects organised in either a 3,2 or 1 dimensional tile array. Each tile in the array contains a singly linked list of objects and status information about the tile.

The dataset tiles can be organised as follows:-

• 3D as RA, DEC and Vmag
• 2D as RA, DEC
• 1D as hashed object ID
• 1D on object distance (for near object datasets)

A dataset is generally equivalent to a table within a traditional database with additional data ordering.

Datasets have a 1:1 mapping with with catalog data files and a catalog can have more than 1 dataset.

Data Structures
struct	lnc_object_class
Typedefs
typedef lnc_dataset	lnc_dataset
	Catalog Dataset.
Enumerations
enum	lnc_ctype {   CT_INT, CT_DOUBLE, CT_FLOAT, CT_STRING,   CT_SIGN, CT_DOUBLE_HMS_HRS, CT_DOUBLE_HMS_MINS, CT_DOUBLE_HMS_SECS,   CT_DOUBLE_DMS_DEGS, CT_DOUBLE_DMS_MINS, CT_DOUBLE_DMS_SECS, CT_DOUBLE_MPC,   CT_NULL }
Functions
lnc_dataset *	lnc_dset_create (lnc_catalog *cat, char *dset_name)
	Create a new dataset.
int	lnc_dset_init (lnc_dataset *dset, lnc_progress progress, int ra, int dec, int mag, unsigned int flags)
	Initialise new dataset.
void	lnc_dset_free (lnc_dataset *dset)
	Free's dataset and it's resources.
int	lnc_dset_add_custom_field (lnc_dataset *dset, char *field)
	Add a custom field to the dataset for importing.
int	lnc_dset_set_alt_index (lnc_dataset *dset, char *field, char *alt, int flags)
	Set an alternative field if another field is blank.
void	lnc_dset_clip_posn (lnc_dataset *dset, double min_ra, double min_dec, double max_ra, double max_dec, double faint_mag, double bright_mag)
	Set dataset clipping area based on position.
void	lnc_dset_clip_dist (lnc_dataset *dset, double min_AU, double max_AU)
	Set dataset clipping area based on distance.
void	lnc_dset_unclip (lnc_dataset *dset)
	Unclip dataset clipping area to full boundaries.
int	lnc_dset_get_objects (lnc_dataset *dset, lnc_progress progress, lnc_slist **result, unsigned int flags)
	Get objects from catalog based on clipping area.
void	lnc_dset_put_objects (lnc_slist *results)
	Release slist memory from lnc_dset_get_objects().
int	lnc_dset_prune (lnc_dataset *dset)
	free all old sectors.
int	lnc_dset_get_size (lnc_dataset *dset)
	Get dataset cache size.
int	lnc_dset_get_object_size (lnc_dataset *dset)
	Get dataset object size.
void	lnc_dset_set_status_posn (lnc_dataset *dset, double min_ra, double min_dec, double max_ra, double max_dec, double faint_mag, double bright_mag, unsigned int status)
	set sector status based upon area
void	lnc_dset_set_status_dist (lnc_dataset *dset, double min_AU, double max_AU, unsigned int status)
	set sector status based upon area
lnc_tile_status	lnc_dset_get_status_posn (lnc_dataset *dset, double ra, double dec, double mag)
	get sector status
lnc_tile_status	lnc_dset_get_status_dist (lnc_dataset *dset, double AU)
	get sector status
lnc_ctype	lnc_dset_get_field_type (lnc_dataset *dset, char *field)
	Get field type in struct.
int	lnc_dset_get_field_offset (lnc_dataset *dset, char *field)
	Get field offset in struct.
int	lnc_dset_for_results_do (lnc_slist *res, void(*func)(void *object, void *data), void *data)
	Do func for every object in result.

---

Typedef Documentation

struct lnc_dataset

Catalog Dataset. The dataset container holds the tile array and it's dimensions. Examples: client.c, and sky2k.c.

---

Enumeration Type Documentation

enum enum lnc_ctype

C type of ASCII dataset field

---

Function Documentation

int lnc_dset_add_custom_field (  lnc_dataset *  dset, char *  field )

Add a custom field to the dataset for importing. Parameters: dset  dataset field  Field name to add Returns: 0 on success Add a custom field to a dataset for import. Examples: client.c, and sky2k.c.

void lnc_dset_clip_dist (  lnc_dataset *  dset, double  min_AU, double  max_AU )

Set dataset clipping area based on distance. Parameters: dset  dataset min_AU  Min AU max_AU  Max AU Clips the dataset to the within the given distance range. Note: Clipping boundaries are not exact and depend on the granularity of the dataset distance stride.

void lnc_dset_clip_posn (  lnc_dataset *  dset, double  min_ra, double  min_dec, double  max_ra, double  max_dec, double  faint_mag, double  bright_mag )

Set dataset clipping area based on position. Parameters: dset  dataset min_ra  Min RA min_dec  Min Dec max_ra  Max RA max_dec  Max Dec faint_mag  Faint Magnitude bright_mag  Bright Magnitude Clips the dataset to the within the given position range. Note: Clipping boundaries are not exact and depend on the granularity of the dataset position strides. Examples: sky2k.c.

lnc_dataset * lnc_dset_create (  lnc_catalog *  cat, char *  dset_name )

Create a new dataset. Parameters: cat  Catalog dset_name  Dataset name (dataset file name in ReadMe) Returns: A lnc_dataset* for success or NULL on error Creates a dataset object. Examples: client.c, and sky2k.c.

int lnc_dset_for_results_do (  lnc_slist *  res, void(*)(void *object, void *data)  func, void *  data )

Do func for every object in result. Parameters: res  Results from get_objects func  Function to call per object in res data  Pointer to pass to func Returns: 0 for success, negative for error Calls func for every object in res. Examples: sky2k.c.

void lnc_dset_free (  lnc_dataset *  dset  )

Free's dataset and it's resources. Parameters: dset  dataset Free dataset resources Examples: client.c, and sky2k.c.

int lnc_dset_get_field_offset (  lnc_dataset *  dset, char *  field )

Get field offset in struct. Parameters: dset  Dataset field  Dataset field name Returns: Field offset in bytes Gets the offset in bytes for a field within a dataset. Examples: sky2k.c.

lnc_ctype lnc_dset_get_field_type (  lnc_dataset *  dset, char *  field )

Get field type in struct. Parameters: dset  Dataset field  Dataset field name Returns: C type Get the C type for a field within a dataset.

int lnc_dset_get_object_size (  lnc_dataset *  dset  )

Get dataset object size. Returns: size in bytes Examples: client.c, and sky2k.c.

int lnc_dset_get_objects (  lnc_dataset *  dset, lnc_progress  progress, lnc_slist **  results, unsigned int  flags )

Get objects from catalog based on clipping area. int lnc_dset_get_objects (lnc_dataset* dset, lnc_progress progress, lnc_slist **result, unsigned int flags) Parameters: dset  dataset progress  Progress callback results  dataset objects flags  Get objects flags Returns: number of objects, or negative for failed Get objects from dataset based on clipping area. Results must be released with lnc_dset_put_objects() after use. Examples: client.c, and sky2k.c.

int lnc_dset_get_size (  lnc_dataset *  dset  )

Get dataset cache size. Parameters: dset  dataset Returns: size in bytes Get dataset memory usage. Examples: client.c, and sky2k.c.

lnc_tile_status lnc_dset_get_status_dist (  lnc_dataset *  dset, double  AU )

get sector status Parameters: dset  Dataset AU  Distance in AU Returns: Status Get the status of objects within a tile at a give distance offset.

lnc_tile_status lnc_dset_get_status_posn (  lnc_dataset *  dset, double  ra, double  dec, double  mag )

get sector status Parameters: dset  Dataset ra  RA in degrees dec  DEC in dergrees mag  Magnitude Get the status of objects within a tile at a give (ra,dec,mag) offset.

lnc_dset_init (  lnc_dataset *  dset, lnc_progress  progress, int  ra, int  dec, int  mag, unsigned int  flags )

Initialise new dataset. Parameters: dset  dataset progress  Progress callback ra  RA stride dec  Dec stride mag  Magnitude stride flags  Init flags Initialise a dataset. This will download and import the raw data if necessary. Examples: client.c, and sky2k.c.

int lnc_dset_prune (  lnc_dataset *  dset  )

free all old sectors. Parameters: dset  dataset Returns: bytes free'd Free's oldest unused object tiles.

void lnc_dset_put_objects (  lnc_slist *  results  )

Release slist memory from lnc_dset_get_objects(). Parameters: results  Results from lnc_dset_get_objects() Releases resources held by the results from lnc_dset_get_objects(). Examples: client.c, and sky2k.c.

int lnc_dset_set_alt_index (  lnc_dataset *  dset, char *  field, char *  alt, int  flags )

Set an alternative field if another field is blank. Parameters: dset  dataset field  Primary field alt  Alternative field flags  flags Set an alternative import field if the primary field is blank. Examples: sky2k.c.

void lnc_dset_set_status_dist (  lnc_dataset *  dset, double  min_AU, double  max_AU, unsigned int  status )

set sector status based upon area Parameters: dset  Dataset min_AU  Minimum distance in AU max_AU  Maximum distance in AU status  Status flags to set Set the status of objects within a given distance range.

void lnc_dset_set_status_posn (  lnc_dataset *  dset, double  min_ra, double  min_dec, double  max_ra, double  max_dec, double  faint_mag, double  bright_mag, unsigned int  status )

set sector status based upon area Parameters: dset  dataset min_ra  Min RA min_dec  Min Dec max_ra  Max RA max_dec  Max Dec faint_mag  Faint Magnitude bright_mag  Bright Magnitude status  Object status Set the status of objects within a given position range.

void lnc_dset_unclip (  lnc_dataset *  dset  )

Unclip dataset clipping area to full boundaries. Parameters: dset  dataset Unclip the dataset to it's full boundaries Examples: client.c, and sky2k.c.

---