Heatmap Layer
A Heatmap Layer visualizes point density with a color ramp.
Each point influences a circular area, most at the center declining towards its outer perimeter.
ID
The dimension represents an identity of the the point. It can also be used as the location id, see "Location Options".
Location, Weight
When coordinates are available specify measures like this:
- latitude - the latitude of the point (WGS 84)
- longitude - the longitude of the point (WGS 84)
- weight - optional measure that controls individual intensity contributions from each point
- Location ID - an identifier that can be used for looking up a location (see Location Options)
- weight - optional measure that controls individual intensity contributions from each point
- weight - optional measure that controls individual intensity contributions from each point
Layer Options
| Property | Use | Description |
|---|---|---|
| Map ID | default:<the most recent map of the sheet> | Specify this value when there is more than one map on a sheet to tell which map to display the layer on. See Map Id in Map Settings of the Map to get the right one. |
| Maximum Number of Objects | default:1000 | To display more than a thousand object increase this value. There will be a warning if there are more objects to display. |
| Calculation Condition | required | To limit when the layer is shown you can enter a caluclation condition as an expression. The layer is calculated/shown only when the expression is fulfilled. |
| Calculation Condition Message | required | A custom error message that will be displayed in the layers legend if the calculation condition is not fulfilled. Only visible if a calculation condition has been entered. |
| Zoom Limit | default:Min 0, Max 160000 | The layer will not be displayed when zoomed further in/out than these values. To set a limit to the current scale, drag the upper or lower limit towards the other and it will snap to the current scale. |
| Restrict Drill Down | default:0-16 | When the dimension is a drill down group it is possible to restrict the layer to be active only for a a range of levels. This makes it easy to create different layers that are active in the different levels of the drill down. The top level is number 0. The range selected specifies at what levels the layer should be visible. |
| Include in Auto Zoom | default:Yes | Determines if the layer should be included when calculating area to zoom to when automatically zooming to selections. |
| Draw Order | default:Auto | Defines how the layer should be drawn compared to other layers, which ones should be drawn on top of each other. |
| Draw Order Category | default:<Layer specific> | The layers are by default drawn after the base map and the base map labels in the order Geodata Layers, Area Layers, Heatmap Layers, Line Layers, Bubble Layers. To make this layer draw in another category, adjust this value. This property is only visible when "Draw Order" is set to "Custom". |
| Draw Order Adjustment | default:0 | Increasing this value makes the layer draw later, i.e. be more visible in the category. Allowed values are in the range -10 to 10. If you want the layer to be on top of other layers in the same category increase this value, if you want it to be overdrawn by other layers in the category decrease it. This property is only visible when "Draw Order" is set to "Custom". |
Location Options
Location information is either specified as longitude, latitude pairs, as identities that are looked up in an external service or as sense geometries.
When the term "Location ID" is used below it means it can be a sense geometry or an identity looked up else where.
When it starts with a "[" it is assumed to be a geometry in a string ([long,lat] is a point, [[long1,lat1],[long2,lat2],...] is a line,
[[[long1,lat1],[long2,lat2],...]] is a multi-line or a polygon with multiple rings, [[[[long1,lat1],[long2,lat2],...]]] is a multi-polygon but also accepted as a multi-line).
The external service can be something as simple as a geometry file or a more complex server based service.
The server based services provide a syntax for specifying more information on identities to minimize false hits.
For instance containing areas and types of features can be specified.
The following is the city Hamburg in Germany:
Hamburg,DE
and this is Hamburg in Sweden:
Hamburg,SE
If you actually wanted the first order administrative area in Germany named Hamburg you also need to specify a type:
Hamburg:AADM1,DE
You can also specify multiple areas when needed. For instance in USA there are many Hamburg. To get the one in Arkansas specify:
Hamburg,AR,US
See
Location Service Specification
for more information on syntax to use.
When there are unresolved names a warning is displayed in the upper left corner of the map.
| Property | Use | Description |
|---|---|---|
| Location Source | default:Auto |
Where location information comes from.
|
| Location Service | default:different for different types of geometries | URL to the location service. Either a server based service or a file as specified in "Location Service Type". An expression is accepted which makes it possible to change source dynamically. This can be used for switching file in different drill down levels for instance. |
| Location Service Type | default:Geometry service | The type of service used for location ID lookup. |
| Source Key Attribute | optional | The attribute in a geometry file to use as the location ID. This field is only visible when a file based geometry service is selected. |
| Advanced Location | default:false | The advanced location toggle controls whether to use Advanced Loction, in essence whether to use Location ID Suffix or to use Country and Type. |
| Country | default:any | The Country dropdown can be used to narrow down a lookup of a location id. Using Country is a simplified way of using Location ID Suffix (see below). |
| Type | default:any | The Type dropdown can be used to narrow down a lookup of a location id. Using Country is a simplified way of using Location ID Suffix (see below). |
| Location ID Suffix | default: |
The specified string is appended to all IDs.
This is a convenient way to specify more information to server based location services such as country code or type.
The alternative is to use an expression in the measure that appends extra information.
With the following suffix all items are specified to be cities in Sweden:
:P*,SE
See
Location Service Specification
for more information on syntax to use.
|
| Manual Remap | default: |
This provides an easy fix for incorrect location IDs. To change them to something else use a syntax like:
"value1":"remapped value1", "value2":"remapped value2", ... |
| Geometry Attribute | default:the_geom | The name of the attribute that contains the geometry (without name space). This field is only visible when Location Service Type is GML/WFS. |
| Reverse Coordinates | default:unchecked | Coordinates are expected in order latitude, longitude or Y, X. Check when coordinates comes in the other order. This field is only visible when Location Service Type is GML/WFS. |
Appearance: Legend
| Property | Use | Description |
|---|---|---|
| Show titles | default:Off | Display standard title. |
| Color legend | default:Auto | Controls if visibility of the parts in the right side of the legend should be in Auto or Custom. |
| Show Colors | default:Checked | Turn on/off the color bar. This option is only visible when "Color legend" is Custom. |
| Show Color Min/Max Values | default:Checked | Turn on/off the text labels for color values. This option is only visible when "Color legend" is Custom. |
| Show Color Title | default:Checked | Turn on/off the label at the right side of the legend. This option is only visible when "Color legend" is Custom. |
| Show Icon Title | default:Checked | Turn on/off the label at the left side of the legend. |
| Show Icon | default:Checked | Turn on/off the heatmap icon. |
Appearance: Heatmap
| Property | Use | Description |
|---|---|---|
| Transparency | default:0 | A slider that controls transparency for entire layer, from no transparency to invisible. |
| Radius | default:20 | The radius of the circle that a point influences. Note that the length unit is set in "Radius Unit". |
| Radius Unit | default:pixels | Available values are pixels and meters. |
| Scale | default:Auto | When set to "Auto" the intensity is adjusted so that the max value is mapped to the highest color in the color ramp. When Custom, an intensity of 1 is mapped to the highest color. Note that the visualization changes when panning or zooming to adjust the highest intensity to the highest color. If you want a visualization that is constant during pans, zooms and changes of the selection, set this property to "Custom". |
| Weight Factor | default:1 | This option is only visible when "Scale" is "Custom". Multiplies all source values with a constant. The same effect can be achieved by multiplying the measure with the same constant. |
| Color Mode | default:Auto | Switch that sets colors to Auto, the default colors, or Custom, where colors can be specified. |
| Colors | default:"a transparent-turquoise-green yellow-red color ramp" | The colors to use when coloring the heat map, in CSS format (e.g. red, #C0FFEE, rgba(31,41,59,0.26)) with commas between. For instance specifying "rgb(255,255,255),rgb(255,0,0)" would produce a color ramp between white and red. Should contain at least two values. The heat map creates linear gradients between the colors unless you specify values in Color distribution. This property is only visible when Color mode is Custom. |
| Color Distribution | default: | How the colors specified in Colors should be distributed along the color ramp. There must be one value per color. First must be 0 and last 1. If no value is specified the colors are distributed evenly. This property is only visible when Color mode is Custom. |