GeoGridLines

GeoGridLines

is an option for GeoGraphics that specifies what parallels and meridians to show.

Details

  • The following settings can be given for GeoGridLines:
  • Noneno geo grid lines drawn
    Automaticgeo grid lines placed automatically
    napproximate number of parallels and meridians
    Quantity[]geo grid lines placed at multiples of an angular quantity
    {latgrid,longrid}geo grid lines specified separately for latitude and longitude
  • With the Automatic setting, geo grid lines are usually placed at points whose coordinates have the minimum number of digits in their decimal representation.
  • For each latitude/longitude coordinate, the following grid line options can be given:
  • Noneno geo grid lines drawn
    Automaticgeo grid line positions chosen automatically
    napproximate number of parallels and meridians
    Quantity[]geo grid lines placed at multiples of an angular quantity
    {x1,x2,}geo grid lines drawn at the specified positions
    {{x1,style1},}geo grid lines with specified styles
    funcfunction to be applied to xmin, xmax to get geo grid line option
  • When a positive integer n is specified for either latitude or longitude, various heuristics are applied to produce "nice" geo grid lines. As a result, the number of grid lines actually shown may not be exactly n.
  • For GeoGridLines->n or GeoGridLines->Automatic, the number of grid lines shown may differ between parallels and meridians.
  • For a Quantity specification, only angular quantities are supported.
  • The geo grid line function func[xmin,xmax] may return any other geo grid line option.
  • AbsoluteOptions can be used to extract explicit lists of latitudes and longitudes that were used for GeoGridLines specifications given Automatic settings.
  • Use GeoGridLinesStyle to set styles for geo grid lines.

Examples

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Basic Examples  (3)

Overlay a map with geo grid lines using default styling:

Use the Albers projection:

Draw geo grid lines at specific lines of latitude and longitude:

Specify geo grid styles:

Scope  (8)

GeoGridLines Positions  (5)

Place the geo grid lines automatically:

Draw geo grid lines at specific lines of latitude:

Draw geo grid lines at specific lines of longitude:

Draw geo grid lines at specific lines of latitude and longitude:

Specify the target number of geo grid lines:

Specify different numbers of latitude and longitude geo grid lines:

Draw geo grid lines as multiples of a given angle:

GeoGridLines Styling  (3)

Specify the style of each geo grid line:

Specify overall geo grid line style using GeoGridLinesStyle:

Individually styled geo grid lines can be used with GeoGridLinesStyle and have higher priority:

Generalizations & Extensions  (1)

Specify a grid function applied to xmin and xmax values of each direction:

Applications  (2)

Plot a solid line at multiples of 30° and a dashed line at multiples of 10°:

Show geo grid lines on the Bonne projection:

Properties & Relations  (2)

Geo grid lines are always drawn above the graphics:

Use AbsoluteOptions to get the grid lines used with an Automatic setting:

Possible Issues  (4)

Specifying GeoGridLinesStyle in addition to a GeoGridLines style may give a different result:

Geo grid lines may be specified as an angular quantity:

Geo grid lines may not be specified as a distance quantity:

Integer arguments and option settings for several geo functions are interpreted as distances (or radii) in meters:

However, an integer geo grid line specification indicates an approximate number of "nice" grid lines to display:

Use GeoPath to interactively display geo coordinates of geo lines:

Neat Examples  (3)

A random collection of geo grid lines:

Use geo grid lines with 1° graticule over Australia:

Plot geo grid lines at positions of the largest US cities:

Compute their coordinates:

Display a map of the US with lines of latitude and longitude passing through the largest cities:

Introduced in 2014
 (10.0)