Web Map Service

Overview

Kinetica provides a Web Map Service (WMS) for generating image tiles from the geospatial data contained in it. The type of image tiles returned, the data used to generate the tiles, and the graphical styles in the tiles are specified in the query string of the WMS call. These would typically be used as overlays on top of a map. Examples of this can be seen in the demo that comes bundled with Kinetica at http://<host>:8080/gaiademo. Any table with x,y coordinates or WKT shapes can be used as the source for generating images.

Note that the cb_raster and raster styles have a GEO_ATTR parameter that allows specifying the name of a geometry (WKT) column to use during rendering. This parameter is optional as Kinetica will automatically find a geometry column, but if there's multiple geometry columns and a specific column needs to be used, GEO_ATTR is necessary. If the specified GEO_ATTR column exists and is a geometry-type column, Kinetica will continue with rendering. If the column does not exist or it is not a geometry-type column, Kinetica will try to process the column as point or track data instead.

Important

If GEO_ATTR is not specified and there's more than one geometry column, Kinetica will attempt to process the columns as point or track data.

The requested image is then returned in the HTTP response message body.

Downloads

The examples below use the following tables:

• nyc_neighborhood
• flights (downloadable via GAdmin)
• nyctaxi (downloadable via GAdmin)

Required Parameters

The following parameters are required in all WMS calls:

Name	Description	Allowable Values
REQUEST	WMS Request	GetMap for getting an image GetCapabilities is also supported
SRS	Spatial Reference System (i.e. EPSG code)	Plate Carree projection codes: PLATE_CARREE, EPSG:4326 Web Mercator projection codes: WEB_MERCATOR, 900913, EPSG:900913, 102100, EPSG:102100, 3857, EPSG:3857
LAYERS	The requested image layer(s)	One or more comma-separated table names
BBOX	Geographic bounding box as a comma-separated list of: min_longitude, min_latitude, max_longitude, max_latitude	Four comma-separated numerics
WIDTH	Image width, in pixels; best performance if a power of 2	64 - 8192
HEIGHT	Image height, in pixels; best performance if a power of 2	64 - 8192

Optional Parameters

The following parameters are optional for WMS calls:

Name	Description	Allowable Values	Default Value
VERSION	WMS Version--only v1.1.1 is supported	1.1.1	1.1.1
STYLES	The mode of image requested	raster cb_raster heatmap contour labels	raster
FORMAT	Output image format--only PNG is supported	image/png	image/png
TRANSPARENT	Controls background transparency of the generated image	TRUE for transparent background FALSE for opaque background	TRUE
X_ATTR	Name of the column to be used as the longitude	Numeric column from LAYERS source table list; must be of int, double, float, or long column type	Column x
Y_ATTR	Name of the column to be used as the latitude	Numeric column from LAYERS source table list; must be of int, double, float, or long column type	Column y
GEO_ATTR	The WKT attribute used to render the raster/cb_raster (particularly if you have more than one WKT column in the table)	A WKT column name

Modes

The following modes are supported, as specified by the STYLES parameter:

• raster
• cb_raster
• heatmap
• contour
• labels

Descriptions of each mode along with the mode-specific parameters can be found below.

RASTER

The raster mode is used to rasterize points, shapes, symbols, and/or tracks from one or more tables. Available parameters are:

Name	Description	Allowable Values	Default Value
DOPOINTS	Rasterize point data toggle	TRUE or FALSE	TRUE
DOSHAPES	Rasterize shapes toggle	TRUE or FALSE	TRUE
DOSYMBOLOGY	Rasterize symbols toggle	TRUE or FALSE	FALSE
DOTRACKS	Rasterize tracks	TRUE or FALSE	TRUE
HASHLINEANGLES	Clockwise rotation angle from a perpendicular hash line in degree	Real numbers	0
HASHLINECOLORS	RBG color values in hex for the hash lines	Hex color (or -1 for same color as shapeline)	SHAPELINECOLOR value
HASHLINEINTERVALS	Distance between the center points of hash lines in pixels	Positive integers	20
HASHLINELENS	Length of hash lines in pixels. Inputting a 0 disables hash lines	Non-negative integers	0
HASHLINEWIDTHS	Width of hash lines in pixels	Positive integers	3
ORDER_LAYERS	Enables layers to be rendered in the order they were specified in	true or false
POINTCOLORS	Color of points	Hex color	FF0000 (red)
POINTOFFSET_X	Horizontal offset for point location in pixels	Signed integers	0
POINTOFFSET_Y	Vertical offset for point location in pixels	Signed integers	0
POINTSHAPES	Shape of points	none circle square diamond hollowcircle hollowsquare hollowdiamond SYMBOLCODE (to specify a symbol)
POINTSIZES	Size of points	0 - 20	3
SHAPEFILLCOLORS	Fill color for closed shapes (i.e. polygons)	Hex color (or -1 for no fill)	-1 (no fill)
SHAPELINECOLORS	Line colors for shapes	Hex color	FFFF00 (yellow)
SHAPELINEPATTERNLENS	Lengths of dashed-line patterns in number of bits	1 - 64	0
SHAPELINEPATTERNS	Bitmaps representing dashed-line patterns; bits of 1 enable the pixels associated with them, but if all bits are 0, dashed-line drawing is disabled, i.e. solid lines are drawn	Unsigned 64-bit (hexadecimal) integers	0
SHAPELINEWIDTHS	Line widths of shapes	0 - 20	3
SYMBOLROTATIONS	Angle in degree for clockwise symbol rotation	Numeric constants or expressions (including column names)
TRACKHEADCOLORS	Color of track head markers	Hex color	FFFFFF (white)
TRACKHEADSHAPES	Shape of track head markers	none circle square diamond hollowcircle hollowsquare hollowdiamond SYMBOLCODE (to specify a symbol)	circle
TRACKHEADSIZES	Size of track head markers	0 - 20	10
TRACKLINECOLORS	Line colors for tracks	Hex color	00FF00 (green)
TRACKLINEWIDTHS	Line widths of tracks	0 - 20 (0: don't draw the track lines)	3
TRACKMARKERCOLORS	Color of track point markers	Hex color	0000FF (blue)
TRACKMARKERSHAPES	Shape of track point markers	none circle square diamond hollowcircle hollowsquare hollowdiamond SYMBOLCODE (to specify a symbol)	none
TRACKMARKERSIZES	Size of track point markers	0 - 20	2

Important

The WORLDLAYERS parameter can be used if the table(s) specified in the LAYERS parameter only have a subset of all track points and the desired behavior is to render the entire track. In this case the unique track ids existing in the LAYERS table(s) will be identified, but the actual track points will be pulled from the WORLDLAYERS table(s).

Styling parameters must be specified for each table provided in the LAYERS parameter. For instance, if LAYERS=LAYER1,LAYER2 then to set different point colors for each layer the syntax would be: POINTCOLORS=FF0000,0000FF. In this case points from LAYER1 would be rendered as red while points from LAYER2 would be rendered as blue. If styling parameters are not provided for a layer, the default value is applied.

All colors must be provided in hex notation in the format RRGGBB or AARRGGBB (to specify the alpha value). For example, opaque red may be given as FF0000 or FFFF0000.

To use symbols rather than points, the source table(s) must have an unrestricted string type column named SYMBOLCODE, which is the desired symbol's identifier. All necessary symbols need to be added via the /insert/symbol endpoint. The IDs in the SYMBOLCODE column must match up with the IDs of the inserted symbols.

Note

Labels and shapes cannot be rendered in the same WMS call. Both can be shown on the same map by creating separate map layers, each with its own WMS call.

For example, to generate a raster image from a table nyc_neighborhood with the following characteristics:

• SRS is EPSG:4326
• Bounding box longitude is from -74.1 to -73.9 and latitude is from 40.6 to 40.9
• Image size is 1024 x 1024
• The geometry column used to render the raster image is geom
• The raster image will render shapes because DOSHAPES is set to TRUE

http://${HOSTNAME}:9191/wms?REQUEST=GetMap
&SRS=EPSG:4326
&LAYERS=nyc_neighborhood
&BBOX=-74.1,40.6,-73.9,40.9
&WIDTH=1024
&HEIGHT=1024
&STYLES=raster
&GEO_ATTR=geom
&DOSHAPES=TRUE

To generate a raster image from a table Flights with the following characteristics:

• SRS is EPSG:4326
• Bounding box longitude is from -180 to 180 and latitude is from -90 to 90
• Image size is 512 by 512
• Track rendering is enabled
• Track headers are diamond-shaped
• Track marker color is set to 006BBB
• Track markers are square-shaped
• Track line color is set to 80858E

http://${HOSTNAME}:9191/wms?REQUEST=GetMap
&SRS=EPSG:4326
&LAYERS=flights
&BBOX=-180,-90,180,90
&WIDTH=512
&HEIGHT=512
&STYLES=raster
&DOTRACKS=1
&TRACKHEADSHAPES=diamond
&TRACKMARKERCOLORS=006BBB
&TRACKMARKERSHAPES=square
&TRACKLINECOLORS=80858E

CB_RASTER

The class break raster mode is for generating class break renderings. A class break rendering is the rasterization of the data from one or more tables with styling applied on a per-class basis. Distinct values (for strings) or ranges (for numeric columns) must be provided in the CB_VALS parameter.

Important

All RASTER mode parameters except SYMBOLROTATIONS and ORDER_LAYERS can be used with the CB_RASTER mode in addition to the parameters listed below

Name	Description	Allowable Values	Default Value
CB_ATTR	Class break attribute (Required)	Any column from the LAYERS source table list
CB_VALS	Values or ranges to apply for the class break (Required) NOTE: The starting value of the range is inclusive and the end value is exclusive	List of values or ranges separated by CB_DELIMITER (e.g., 0:5,5:10,15:30) This specifies three ranges: 0 up to but not including 5 5 up to but not including 10 15 up to but not including 30
CB_DELIMITER	A group of characters which separate values or ranges in CB_VALS. Default value is ,	Alpha-numeric or special characters	,
ORDER_CLASSES	Enables classes to be rendered in the order they were specified	TRUE or FALSE	FALSE
USE_POINT_RENDERER	Set to TRUE to render points larger than 1 pixel; if FALSE, all points will be 1 pixel. NOTE: Only used when OpenGL rendering is disabled	TRUE or FALSE	FALSE
CB_POINTCOLOR_ATTR	Class break attribute applied to only the point color. Overrides CB_ATTR when applied	Any column from the LAYERS source table list
CB_POINTCOLOR_VALS	Values or ranges to apply for the CB_POINTCOLOR_ATTR class break NOTE: The starting value of the range is inclusive and the end value is exclusive	List of values or ranges separated by CB_DELIMITER (e.g., 0:5,5:10,15:30) This specifies three ranges: 0 up to but not including 5 5 up to but not including 10 15 up to but not including 30
CB_POINTSIZE_ATTR	Class break attribute applied to only the point size. Overrides CB_ATTR when applied	Any column from the LAYERS source table list
CB_POINTSIZE_VALS	Values or ranges to apply for the CB_POINTSIZE_ATTR class break NOTE: The starting value of the range is inclusive and the end value is exclusive	List of values or ranges separated by CB_DELIMITER (e.g., 0:5,5:10,15:30) This specifies three ranges: 0 up to but not including 5 5 up to but not including 10 15 up to but not including 30
CB_POINTSHAPE_ATTR	Class break attribute applied to only the point shape. Overrides CB_ATTR when applied	Any column from the LAYERS source table list
CB_POINTSHAPE_VALS	Values or ranges to apply for the CB_POINTSHAPE_ATTR class break NOTE: The starting value of the range is inclusive and the end value is exclusive	List of values or ranges separated by CB_DELIMITER (e.g., 0:5,5:10,15:30) This specifies three ranges: 0 up to but not including 5 5 up to but not including 10 15 up to but not including 30

All of the RASTER-mode styling parameters are valid for CB_RASTER (except SYMBOLROTATIONS); however, there must be styling parameters specified for each class. Each entry in CB_VALS connotes an individual class to which styling is applied. If styling parameters are not provided for a class, the default value is applied.

The per-style class break parameters (CB_POINTCOLOR..., CB_POINTSIZE..., and CB_POINTSHAPE...) can be used to override attribute color, size, or shapes if the given data falls into the given range, e.g., enlarge a point's size if its total sales amount was greater than some amount.

The keyword <other> can be used as a value in CB_VALS instead of a class name to render all non-matching classes as specified by corresponding style options. The length of the style options must match the number of classes specified (including <other>).

For example, to generate a category-based class-break raster image from a table nyctaxi with the following characteristics:

• SRS is PLATE_CARREE
• Bounding box longitude is from -74.1 to -73.9 and latitude is from 40.6 to 40.9
• Image size is 1024 x 1024
• X-axis position is extracted from the nyctaxi table's pickup_longitude column
• Y-axis position is extracted from the nyctaxi table's pickup_latitude column
• Passenger count is extracted from the nyctaxi table's passenger_count column
• Classes are:
  1. Between 1 and 2 passengers -- diamonds colored yellow (999900)
  2. Between 3 and 5 passengers -- circles colored orange (CC6600)
  3. Anything else (as designated by the <other> keyword) -- squares colored red (FF0000)
• ORDER_CLASSES is enabled, so 999900 will be rendered first, CC6600 will be rendered below that, and FF0000 below that
• Points have a size of 2

http://${HOSTNAME}:9191/wms?REQUEST=GetMap
&SRS=PLATE_CARREE
&LAYERS=nyctaxi
&BBOX=-74.1,40.6,-73.9,40.9
&WIDTH=1024
&HEIGHT=1024
&STYLES=cb_raster
&X_ATTR=pickup_longitude
&Y_ATTR=pickup_latitude
&CB_ATTR=passenger_count
&CB_VALS=1:3,3:5,<other>
&POINTCOLORS=999900,CC6600,FF0000
&ORDER_CLASSES=true
&POINTSIZES=2
&POINTSHAPES=diamond,circle,square

HEATMAP

The heatmap mode is used to generate a heat map image of one or more tables. Heatmaps are a visual representation of the information contained in the given tables.

Available parameters are:

Name	Description	Allowable Values	Default Value
BLUR_RADIUS	Blurring radius for the heat map	1 - 32	5
COLORMAP	Colormap for the heat map	Perceptually-Uniform - viridis, inferno, plasma, magma Sequential I - Blues, BuGn, BuPu, GnBu, Greens, Greys, Oranges, OrRd, PuBu, PuBuGn, PuRd, Purples, RdPu, Reds, YlGn, YlGnBu, YlOrBr, YlOrRd Sequential II - afmhot, autumn, bone, cool, copper, gist_heat, gray, gist_gray, gist_yarg, binary, hot, pink, spring, summer, winter Diverging - BrBG, bwr, coolwarm, PiYG, PRGn, PuOr, RdBu, RdGy, RdYlBu, RdYlGn, Spectral, seismic Qualitative - Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3 Misc - gist_earth, terrain, ocean, gist_stern, brg, CMRmap, cubehelix, gnuplot, gnuplot2, gist_ncar, spectral, nipy_spectral, jet, rainbow, gist_rainbow, hsv, flag, prism	jet
GRADIENT_START_COLOR	Gradient start color for the heat map	Hex color	000000 (black)
GRADIENT_END_COLOR	Gradient end color for the heat map	Hex color	000000 (black)
VAL_ATTR	Attribute to use to calculate the data points for the heat map	Column from LAYERS source table list; must be of int, double, float, long, or decimal column type. Can invoke several "behaviors"; See below for more information.	(none)

For the Heatmap mode in particular, the BBOX parameter defines the geographic area while the WIDTH and HEIGHT parameters define the pixel grid resolution over which the heatmap will be calculated.

If COLORMAP is specified, it will be used regardless of whether GRADIENT_START_COLOR/GRADIENT_END_COLOR are specified. If the given colormap is invalid, an error will be returned. If COLORMAP is blank or unspecified, GRADIENT_START_COLOR/GRADIENT_END_COLOR are used, if specified. If none of these is specified, the jet colormap will be used.

VAL_ATTR can be used to enable special behaviors. A description of the behavior as well as how to enable the behavior can be found below.

• Count - the number of records at each pixel is used to generate the heatmap
  • If no VAL_ATTR is specified or VAL_ATTR=
  • VAL_ATTR=count(column_name)
• Sum - the sum of column_name within each pixel is used to generate the heatmap
  • VAL_ATTR=column_name
  • VAL_ATTR=sum(column_name)
• Average - the average of column_name within each pixel is used to generate the heatmap
  • VAL_ATTR=avg(column_name)
  • VAL_ATTR=mean(column_name)
• Minimum - the minimum of column_name within each pixel is used to generate the heatmap
  • VAL_ATTR=min(column_name)
• Maximum - the maximum of column_name within each pixel is used to generate the heatmap
  • VAL_ATTR=max(column_name)

For example, to generate a heatmap image from a table nyctaxi with the following characteristics:

• SRS is PLATE_CARREE
• Bounding box longitude is from -80 to -70 and latitude is from 35 to 45
• Image size is 512 x 512
• X-axis position is extracted from the nyctaxi table's pickup_longitude column
• Y-axis position is extracted from the nyctaxi table's pickup_latitude column
• A blur radius of 5
• A plasma colormap

http://${HOSTNAME}:9191/wms?REQUEST=GetMap
&SRS=PLATE_CARREE
&LAYERS=nyctaxi
&BBOX=-80,35,-70,45
&WIDTH=512
&HEIGHT=512
&STYLES=heatmap
&BLUR_RADIUS=5
&X_ATTR=pickup_longitude
&Y_ATTR=pickup_latitude
&COLORMAP=plasma

CONTOUR

The contour mode is used to generate a contour plot image of one or more tables. A contour plot is a plane section of the three-dimensional graph of the function z = f(x, y) parallel to the x, y plane. Contour plots contain isolines, which show the location(s) where the data has the same z value.

Available parameters are:

Name	Description	Allowable Values	Default Value
COLORMAP	Colormap for the contour or contour grid.	Perceptually-Uniform - viridis, inferno, jet, plasma, magma Sequential I - Blues, BuGn, BuPu, GnBu, Greens, Greys, Oranges, OrRd, PuBu, PuBuGn, PuRd, Purples, RdPu, Reds, YlGn, YlGnBu, YlOrBr, YlOrRd Sequential II - afmhot, autumn, bone, cool, copper, gist_heat, gray, gist_gray, gist_yarg, binary, hot, pink, spring, summer, winter Diverging - BrBG, bwr, coolwarm, PiYG, PRGn, PuOr, RdBu, RdGy, RdYlBu, RdYlGn, Spectral, seismic Qualitative - Accent, Dark2, Paired, Pastel1, Pastel2, Set1, Set2, Set3 Misc - gist_earth, terrain, ocean, gist_stern, brg, CMRmap, cubehelix, gnuplot, gnuplot2, gist_ncar, spectral, nipy_spectral, jet, rainbow, gist_rainbow, hsv, flag, prism	jet
COLOR	Isoline color to be used when flooded contours are enabled; otherwise isolines will follow the colormap	Hex notation in the format RRGGBB or AARRGGBB, in which case the alpha value is used for the transparency of the flooded contours. The line itself is always opaque.	''FF000000''
BG_COLOR	Background color	Hex notation in the format RRGGBB or AARRGGBB (to specify the alpha value)	''00000000'' (transparent)
TEXT_COLOR	Color of labels text	Hex notation in the format RRGGBB or AARRGGBB (to specify the alpha value)	''FF000000''
MIN_LEVEL	Minimum isoline value to be shown.	Number	-1
MAX_LEVEL	Maximum isoline value to be shown.	Number	-1
NUM_LEVELS	Number of equally-separated isolines to be shown.	10 or greater	10
ADJUST_LEVEL	Recompute the minimum and maximum levels based on the current data in the viewport. Setting this will ignore the values of MIN_LEVEL and MAX_LEVEL.	Number	1
VAL_ATTR	Attribute to use to calculate the isolines.	Column from LAYERS source table list; must be of int, double, float, long, or decimal column type. Can invoke several "behaviors"; See below for more information.	z
SEARCH_RADIUS	Neighborhood of influence of sample data (in percent of the image/grid). See below for more information.	Number	1
GRIDDING_METHOD	Methods to produce a regularly-spaced, rectangular array of values from potentially irregularly-spaced XY-val data. See below for more information.	INV_DST_POW -- Inverse Distance to a Power; a weighted average interpolator that can either be an exact or a smoothing interpolator	INV_DST_POW
SMOOTHING_FACTOR	Amount of smoothing of the contribution of neighboring points.	Number between 0 and 1	0.01
MAX_SEARCH_CELLS	Maximum number of cells to use once the SEARCH_RADIUS has been converted from percentage to cells. The higher the number, the higher the quality of the contour plot.	Number	100
RENDER_OUTPUT_GRID	Show the grid used to build the contour plot, which is equivalent to generating a flooded-contour. This affects the labels by clipping the area around them. The opacity of the flooded-contours is specified in ''COLOR''.	0 (false) or 1 (true)	0
GRID_SIZE	Number of subdivisions along the x axis when building the grid. The y axis will be set according to the aspect ratio.	Number	100
ADJUST_GRID	Allows the grid size and search radius to be automatically varied based on the current data in the viewport.	0 (false) or 1 (true)	0
ADJUST_GRID_NEIGH	Used to estimate the clustering of the data (k-means) when ADJUST_GRID is set to 1. Clustering estimation is capped by MAX_SEARCH_CELLS.	Number between 0 and 1	1
ADJUST_GRID_SIZE	Size of the sampling grid used to compute the fill and clustering ratios when ADJUST_GRID is set to 1.	Number	20
MIN_GRID_SIZE	Lower limit (in cells) of the grid size when ADJUST_GRID is set to 1	Number	10
MAX_GRID_SIZE	Upper limit (in cells) of the grid size when ADJUST_GRID is set to 1	Number	500
ADD_LABELS	Add label contour lines with the value of their level.	0 (false) or 1 (true)	0
LABELS_FONT_SIZE	Size of the font to use for labels.	Number between 4 and 48	12
LABELS_FONT_FAMILY	Name of the font to use for labels. The font must be on the system.	Any font codes available on all database servers	Sans
LABELS_SEARCH_WINDOW	When ADD_LABELS is set to 1, a search window is used to rate the local quality of each isoline. Smooth, continuous, long stretches with relatively flat angles are favored. This setting is multiplied by the font size to set the final window size.	Number between 1 and 8	4
LABELS_INTRALEVEL_SEPARATION	When ADD_LABELS is set to 1, labels are automatically separated to avoid overlap. This setting specifies the distance to use when separating labels of different values (in multiples of the font size).	Number between 1 and 8	4
LABELS_INTERLEVEL_SEPARATION	When ADD_LABELS is set to 1, more than one label can placed on the same isoline. This setting specifies the distance to use when separating labels of the same value (in percent of the total window size).	Number between 0 and 50	25
LABELS_MAX_ANGLE	Maximum angle , in degrees, from the vertical to use when displaying labels.	Number between 0 and 90	60

To be able to construct a contour plot, we first need to grid the data in a regularly-spaced XY array. This is achieved using the GRIDDING_METHOD parameter, which is the most influential parameter of the contour plot. The GRIDDING_METHOD determines how the data is interpolated/extrapolated and will also impact the speed at which the plot can be generated. The only method supported at this time is INV_DST_POW (Inverse Distance to a Power).

The SEARCH_RADIUS heavily influences both the quality and speed of the contour plot. It is method dependent and should be adjusted based on the quantity and quality of the input data.

Once the grid is obtained, a marching squares algorithm is used to obtain the isolines. The grid can be visualized by setting RENDER_OUTPUT_GRID to 1 (true).

Additionally, we can set ADJUST_GRID to 1 (true) if the density of the data in the current viewport is so low that the resulting grid is not filled properly when using the user-specified grid size and search radius. This option will automatically adapt the grid size and/or search radius to get a better interpolation of the data by first running a coarse gridding pass, then collecting data about density and sparsity, and finally choosing the latter value accordingly before re-running the contour lines generation.

Finally, labels can be added to the isolines by setting ADD_LABELS to 1. Label font size, font family, angle, and separation are the main parameters to control how the labels are displayed.

For example, to generate a contour plot image from a table with the following characteristics:

Note

The contour plot image for this example is generated from an aggregate groupby result table contour_source. This result table aggregates dropoff points and counts of points from the nyctaxi table.

curl -sS -X POST --header "Content-Type: application/json" \
--data '{"table_name":"nyctaxi", "column_names":["dropoff_longitude","dropoff_latitude","float(count(*)) as dropoff_point_count"], "offset":0, "limit":-9999, "encoding":"json", "options":{"result_table":"contour_source"}}' \
http://${HOSTNAME}:9191/aggregate/groupby

• SRS is PLATE_CARREE

• Bounding box longitude is from -74.1 to -73.9 and latitude is from 40.6 to 40.9

• Image size is 512 x 512

• X-axis position is extracted from the contour_source table's dropoff_longitude column

• Y-axis position is extracted from the contour_source table's dropoff_latitude column

• Number of individually-separated isolines is set to 150

• Number of isolines is automatically adjusted based on the viewport

• Z value for the contour plot isolines is extracted from the contour_source table's dropoff_point_count column

• Search radius for the isolines is 15% of the grid

• Grid size is manually set to 50

• Labels are added; labels of different values are separated by a space worth 5 times the font size (default font size is 12)

  http://${HOSTNAME}:9191/wms?REQUEST=GetMap
  &SRS=PLATE_CARREE
  &LAYERS=contour_source
  &BBOX=-74.1,40.6,-73.9,40.9
  &WIDTH=512
  &HEIGHT=512
  &STYLES=contour
  &FORMAT=image/png
  &X_ATTR=dropoff_longitude
  &Y_ATTR=dropoff_latitude
  &COLORMAP=jet
  &NUM_LEVELS=150
  &ADJUST_LEVEL=1
  &VAL_ATTR=dropoff_point_count
  &SEARCH_RADIUS=15
  &GRIDDING_METHOD=INV_DST_POW
  &GRID_SIZE=50
  &ADD_LABELS=1
  &LABELS_INTRALEVEL_SEPARATION=5
  "
  

LABELS

The labels mode is used to show labels on the map rather than points. Available parameters are:

Name	Description	Allowable Values	Default Value
LABEL_LAYER	name of table to render (Required)
LABEL_X_ATTR	name of column containing label's position on the x-axis	Numeric column from LABEL_LAYER source table list; must be of int, double, float, or long column type	Column x
LABEL_Y_ATTR	name of column containing label's position on the y-axis	Numeric column from LABEL_LAYER source table list; must be of int, double, float, or long column type	Column y
LABEL_TEXT_STRING	text of label to render	All printable characters	no text
LABEL_FONT	font in the format of Name Style(s) Size (e.g. Arial Bold 8)	Any font codes available on all database servers	default server font
LABEL_TEXT_COLOR	text color	Hex color (with or without alpha values) or -1 (full transparency)	FF000000
LABEL_TEXT_SCALE	text scaling factor	Number	1
LABEL_TEXT_ANGLE	number of degrees clockwise to rotate the label	Number	0
LABEL_DRAW_BOX	draw a box around the label	0 (false) or 1 (true)	0
LABEL_DRAW_LEADER	draw a leader line from each label to its x,y point specified by LABEL_LEADER_X_ATTR & LABEL_LEADER_Y_ATTR columns	0 (false) or 1 (true)	0
LABEL_LINE_WIDTH	width of line for box & leader line	Number	1
LABEL_LINE_COLOR	color of line for box & leader line	Hex color (with or without alpha values) or -1 (full transparency)	FF000000
LABEL_FILL_COLOR	color of fill for box	Hex color (with or without alpha values) or -1 (full transparency)	FF000000
LABEL_LEADER_X_ATTR	name of column containing leader line's terminating position on the x-axis (the end opposite the label)	Numeric column from LABEL_LAYER source table list; must be of int, double, float, or long column type	N/A
LABEL_LEADER_Y_ATTR	name of column containing leader line's terminating position on the y-axis (the end opposite the label)	Numeric column from LABEL_LAYER source table list; must be of int, double, float, or long column type	N/A
LABEL_FILTER	boolean expression used to filter which labels are included from LABEL_LAYER		N/A
LABEL_X_OFFSET	horizontally offset the label rendering from the actual coordinate using the given value	Number	N/A
LABEL_Y_OFFSET	vertically offset the label rendering from the actual coordinate using the given value	Number	N/A

Important

When using the labels mode, LABEL_LAYER is required.

All LABELS parameters can use expressions. To read more about the different types of expressions, see expressions. Strings inside expressions must be enclosed in single or double quotes. Expressions inside the LABEL_TEXT_COLOR, LABEL_LINE_COLOR, and LABEL_FILL_COLOR parameters must resolve to 6 or 8 hex digits or the color won't work. Note that if the expression resolves to 6 hex digits, an alpha value of FF is automatically added.

To use labels, the requested TrueType fonts must be loaded on all servers in the Kinetica cluster, in the /usr/share/fonts directory. Kinetica must be restarted to see any new fonts placed in this directory.

Labels and shapes cannot be rendered in the same WMS call. Both can be shown on the same map by creating separate map layers, each with its own WMS call. When making the WMS call for the labels to be generated, the LAYERS parameter (geospatial source table containing the shapes) can be left blank.

LABEL_DRAW_BOX and LABEL_DRAW_LEADER will only take values that are castable to boolean values (e.g., 1 and 0). "TRUE" and "FALSE" are not valid.

All colors must be provided in hex notation in the format RRGGBB or AARRGGBB (to specify the alpha value). For example, partially transparent red may be given as B3FF0000.

Parameters other than the following can be either literals of the appropriate parameter type or column names containing values of the appropriate type:

• LABEL_LAYER
• LABEL_X_ATTR
• LABEL_Y_ATTR
• LABEL_LEADER_X_ATTR
• LABEL_LEADER_Y_ATTR

For example, to generate a label image overlay from a table nyctaxi with the following characteristics:

• SRS is EPSG:4326

• Bounding box longitude is from -74.1 to -73.9 and latitude is from 40.6 to 40.9

• Image size is 512 x 512

• X-axis position is extracted from the nyctaxi table's dropoff_longitude column

• Y-axis position is extracted from the nyctaxi table's dropoff_latitude column

• Label text is dropoff, is white (FFFFFF), scaled to 40% smaller (0.6 x) than normal, rotated 15 degrees clockwise

• A blue-filled (B3006BBB) box is drawn around each label

• Labels are only drawn for dropoff points where the passenger count was greater than 5

  http://${HOSTNAME}:9191/wms?REQUEST=GetMap
  &SRS=EPSG:4326
  &BBOX=-74.1,40.6,-73.9,40.9
  &WIDTH=512
  &HEIGHT=512
  &STYLES=labels
  &LABEL_LAYER=nyctaxi
  &LABEL_X_ATTR=dropoff_longitude
  &LABEL_Y_ATTR=dropoff_latitude
  &LABEL_TEXT_STRING='dropoff'
  &LABEL_TEXT_SCALE=0.6
  &LABEL_TEXT_ANGLE=15
  &LABEL_DRAW_BOX=1
  &LABEL_FILL_COLOR=B3006BBB
  &LABEL_FILTER=passenger_count>5
  &LABEL_TEXT_COLOR=FFFFFF
  "