Ellipse data
Ellipses or circles can be used to display the area around a set point on your map. If you would like to store ellipse or point radius data for an item, you must define the area to be displayed as a JSON string.
The area that you would like to display is defined by using JSON properties:
JSON Property | Definition |
---|---|
centre | The geographic location of the center of the ellipse, expressed in a supported coordinate format. |
axisUnits | The units to use for the axis definitions. The supported units are:
|
semiAxis1 | This property defines the length of the major semi-axis of the ellipse, that is the longest distance from the center point to the edge (in the units that are specified in axisUnits). |
semiAxis2 | The length of the minor semi-axis of the ellipse, that is the shortest distance from the
center point to the edge (in the units that are specified in axisUnits). Note: If a minor semi-axis
is not defined, a circle is drawn. |
rotation | The angle from the X axis (horizontal) to the major semi-axis in a counterclockwise direction. |
rotationUnits | The unit type you want to use for rotation, for example radians or decimal degrees. |
fill | The transparency and color values to apply to the ellipse. Fill uses ARGB values between 0
and 255 to fill the ellipse. There are default values, which are stored in the settings.xml file. If you do not specify
values, and the default is not changed, the fill
is:
|
maxPoints | The maximum number of points used to draw the perimeter of the ellipse. There is a default value, which is stored in the settings.xml file. If you do not specify a value, and the default is not changed, the maximum number of points is set to 100. |
maxSegLength | The maximum length expressed in the specified axisUnits between two points around the perimeter. There is a default value, which is stored in the settings.xml file. If you do not specify a value, and the default is not changed, the maximum segment length is set to 10. |
For
example:
{
"Ellipses": [
{
"centre": "0, 52",
"semiAxis1": 60,
"semiAxis2": 40,
"rotation": 1.5,
"axisUnits": "mile",
"rotationUnits": "rad",
"fill": {
"a": 255,
"r": 255,
"g": 255,
"b": 255
},
"maxPoints": 1000,
"maxSegLength": 8
}]
}
The minimum that is required to define a circle
is:
{
"Ellipses": [
{
"centre": "0, 52",
"semiAxis1": 40
}]
}
The
minimum that is required to define an ellipse is:
{
"Ellipses": [
{
"centre": "0, 52",
"semiAxis1": 60,
"semiAxis2": 40,
}]
}
This definition is a JSON array that can contain the details for one or more ellipses. The definition must be stored either in an attribute that has the semantic type set to
, or you can enter ellipse information in labels, descriptions, or cards as part of their summary or description.Coordinates that are stored in text require an identifying prefix (ELL/) and suffix (//). For example, ELL/ { "Ellipses": [ { "centre": "0, 52", "semiAxis1": 60, "semiAxis2": 40, }] }//.