SQL Extensions

HEAVY.AI implements a number of custom extension functions to SQL.
Rendering
The following table describes SQL extensions available for the HEAVY.AI implementation of Vega.
SQL SELECT
Function
Arguments and Return
convert_meters_to_merc_pixel_width(meters, lon, lat, min_lon, max_lon, img_width, min_width)
Converts a distance in meters in a longitudinal direction from a latitude/longitude coordinate to a pixel size using mercator projection:
meters: Distance in meters in a longitudinal direction to convert to pixel units.
lon: Longitude coordinate of the center point to size from.
lat: Latitude coordinate of the center point to size from.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
img_width: The width in pixels of the view.
min_width: Clamps the returned pixel size to be at least this width.
 Returns: Floating-point value in pixel units. Can be used for the width of a symbol or a point in Vega.
convert_meters_to_merc_pixel_height(meters, lon, lat, min_lat, max_lat, img_height, min_height)
Converts a distance in meters in a latitudinal direction from a latitude/longitude coordinate to a pixel size, using mercator projection:
meters: Distance in meters in a longitudinal direction to convert to pixel units.
lon: Longitude coordinate of the center point to size from.
lat: Latitude coordinate of the center point to size from.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
img_height: The height in pixels of the view.
min_height: Clamps the returned pixel size to be at least this height.
 Returns: Floating-point value in pixel units. Can be used for the height of a symbol or a point in Vega.
convert_meters_to_pixel_width(meters, pt, min_lon, max_lon, img_width, min_width)
Converts a distance in meters in a longitudinal direction from a latitude/longitude POINT to a pixel size. Supports only mercator-projected points.
meters: Distance in meters in a latitudinal direction to convert to pixel units.
pt: The center POINT to size from. The point must be defined in the EPSG:4326 spatial reference system.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
img_width: The width in pixels of the view.
min_width: Clamps the returned pixel size to be at least this width.
 Returns: Floating-point value in pixel units. Can be used for the width of a symbol or a point in Vega.
convert_meters_to_pixel_height(meters, pt, min_lat, max_lat, img_height, min_height)
Converts a distance in meters in a latitudinal direction from an EPSG:4326 POINT to a pixel size. Currently only supports mercator-projected points:
meters: Distance in meters in a longitudinal direction to convert to pixel units.
pt: The center POINT to size from. The point must be defined in the EPSG:4326 spatial reference system.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
img_height: The height in pixels of the view.
min_height: Clamps the returned pixel size to be at least this height.
 Returns: Floating-point value in pixel units. Can be used for the height of a symbol or a point in Vega.
is_point_in_merc_view(lon, lat, min_lon, max_lon, min_lat, max_lat)
Returns true if a latitude/longitude coordinate is within a mercator-projected view defined by min_lon/max_lon, min_lat/max_lat.
lon: Longitude coordinate of the point.
lat: Latitude coordinate of the point.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
 Returns:True if the point is within the view defined by the min_lon/max_lon, min_lat/max_lat; otherwise, false.
is_point_size_in_merc_view(lon, lat, meters, min_lon, max_lon, min_lat, max_lat)
Returns true if a latitude/longitude coordinate, offset by a distance in meters, is within a mercator-projected view defined by min_lon/max_lon, min_lat/max_lat.
lon: Longitude coordinate of the point.
lat: Latitude coordinate of the point.
meters: Distance in meters to offset the point by, in any direction.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
 Returns: True if the point is within the view defined by the min_lon/max_lon, min_lat/max_lat; otherwise, false.
is_point_in_view(pt, min_lon, max_lon, min_lat, max_lat)
Returns true if a latitude/longitude POINT defined in EPSG:4326 is within a mercator-projected view defined by min_lon/max_lon, min_lat/max_lat.
pt: The POINT to check. Must be defined in EPSG:4326 spatial reference system.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
 Returns: True if the point is within the view defined by min_lon/max_lon, min_lat/max_lat; otherwise, false.
is_point_size_in_view(pt, meters, min_lon, max_lon, min_lat, max_lat)
Returns true if a latitude/longitude POINT defined in EPSG:4326 is within a mercator-projected view defined by min_lon/max_lon, min_lat/max_lat.
pt: The POINT to check. Must be defined in EPSG:4326 spatial reference system.
meters: Distance in meters to offset the point by, in any direction.
min_lon: Minimum longitude coordinate of the mercator-projected view.
max_lon: Maximum longitude coordinate of the mercator-projected view.
min_lat: Minimum latitude coordinate of the mercator-projected view.
max_lat: Maximum latitude coordinate of the mercator-projected view.
 Returns: True if a latitude/longitude POINT defined in EPSG:4326, offset by a distance in meters, is within the view defined by min_lon/max_lon, min_lat/max_lat; otherwise, false.

Last modified 1yr ago

Function	Arguments and Return
`convert_meters_to_merc_pixel_width(meters, lon, lat,` `min_lon,` `max_lon,` `img_width,` `min_width)`	Converts a distance in meters in a longitudinal direction from a latitude/longitude coordinate to a pixel size using mercator projection: `meters`: Distance in meters in a longitudinal direction to convert to pixel units. `lon`: Longitude coordinate of the center point to size from. `lat`: Latitude coordinate of the center point to size from. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `img_width`: The width in pixels of the view. `min_width`: Clamps the returned pixel size to be at least this width. Returns: Floating-point value in pixel units. Can be used for the width of a symbol or a point in Vega.
`convert_meters_to_merc_pixel_height(meters, lon, lat,` `min_lat,` `max_lat,` `img_height,` `min_height)`	Converts a distance in meters in a latitudinal direction from a latitude/longitude coordinate to a pixel size, using mercator projection: `meters`: Distance in meters in a longitudinal direction to convert to pixel units. `lon`: Longitude coordinate of the center point to size from. `lat`: Latitude coordinate of the center point to size from. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. `img_height`: The height in pixels of the view. `min_height`: Clamps the returned pixel size to be at least this height. Returns: Floating-point value in pixel units. Can be used for the height of a symbol or a point in Vega.
`convert_meters_to_pixel_width(meters,` `pt,` `min_lon,` `max_lon,` `img_width,` `min_width)`	Converts a distance in meters in a longitudinal direction from a latitude/longitude POINT to a pixel size. Supports only mercator-projected points. `meters`: Distance in meters in a latitudinal direction to convert to pixel units. `pt`: The center POINT to size from. The point must be defined in the EPSG:4326 spatial reference system. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `img_width`: The width in pixels of the view. `min_width`: Clamps the returned pixel size to be at least this width. Returns: Floating-point value in pixel units. Can be used for the width of a symbol or a point in Vega.
`convert_meters_to_pixel_height(meters, pt,` `min_lat,` `max_lat,` `img_height,` `min_height)`	Converts a distance in meters in a latitudinal direction from an EPSG:4326 POINT to a pixel size. Currently only supports mercator-projected points: `meters`: Distance in meters in a longitudinal direction to convert to pixel units. `pt`: The center POINT to size from. The point must be defined in the EPSG:4326 spatial reference system. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. `img_height`: The height in pixels of the view. `min_height`: Clamps the returned pixel size to be at least this height. Returns: Floating-point value in pixel units. Can be used for the height of a symbol or a point in Vega.
`is_point_in_merc_view(lon, lat,` `min_lon,` `max_lon,` `min_lat,` `max_lat)`	Returns true if a latitude/longitude coordinate is within a mercator-projected view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`. `lon`: Longitude coordinate of the point. `lat`: Latitude coordinate of the point. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. Returns:True if the point is within the view defined by the `min_lon`/`max_lon`, `min_lat`/`max_lat`; otherwise, false.
`is_point_size_in_merc_view(lon, lat,` `meters,` `min_lon,` `max_lon,` `min_lat,` `max_lat)`	Returns true if a latitude/longitude coordinate, offset by a distance in meters, is within a mercator-projected view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`. `lon`: Longitude coordinate of the point. `lat`: Latitude coordinate of the point. `meters`: Distance in meters to offset the point by, in any direction. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. Returns: True if the point is within the view defined by the `min_lon`/`max_lon`, `min_lat`/`max_lat`; otherwise, false.
`is_point_in_view(pt,` `min_lon,` `max_lon,` `min_lat,` `max_lat)`	Returns true if a latitude/longitude POINT defined in EPSG:4326 is within a mercator-projected view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`. `pt`: The POINT to check. Must be defined in EPSG:4326 spatial reference system. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. Returns: True if the point is within the view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`; otherwise, false.
`is_point_size_in_view(pt, meters,` `min_lon,` `max_lon,` `min_lat,` `max_lat)`	Returns true if a latitude/longitude POINT defined in EPSG:4326 is within a mercator-projected view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`. `pt`: The POINT to check. Must be defined in EPSG:4326 spatial reference system. `meters`: Distance in meters to offset the point by, in any direction. `min_lon`: Minimum longitude coordinate of the mercator-projected view. `max_lon`: Maximum longitude coordinate of the mercator-projected view. `min_lat`: Minimum latitude coordinate of the mercator-projected view. `max_lat`: Maximum latitude coordinate of the mercator-projected view. Returns: True if a latitude/longitude POINT defined in EPSG:4326, offset by a distance in meters, is within the view defined by `min_lon`/`max_lon`, `min_lat`/`max_lat`; otherwise, false.