pyguymer3.geo

A Python sub-module containing a bunch of random geo-related functions that I have written over the years.

Notes

See the following two sources of documentation from GIS software to read a bit more about buffering:

• ArcGIS buffering

• QGIS buffering

To clarify some the geometry data types:

• A shapely.geometry.point.Point is made up of a shapely.coords.CoordinateSequence of 1 tuple of a (lon,lat) pair.

• A shapely.geometry.polygon.LinearRing is made up of a shapely.coords.CoordinateSequence of N tuple of (lon,lat) pairs.

• A shapely.geometry.linestring.LineString is made up of a shapely.coords.CoordinateSequence of N tuple of (lon,lat) pairs.

• A shapely.geometry.polygon.Polygon is made up of a shapely.geometry.polygon.LinearRing exterior (and maybe N shapely.geometry.polygon.LinearRing interiors).

• A shapely.geometry.multipoint.MultiPoint is made up of N shapely.geometry.point.Point.

• A shapely.geometry.multilinestring.MultiLineString is made up of N shapely.geometry.linestring.LineString.

• A shapely.geometry.multipolygon.MultiPolygon is made up of N shapely.geometry.polygon.Polygon.

The basic call graphs for pyguymer3.geo.buffer() and pyguymer3.geo.fillin() are:

• pyguymer3.geo.buffer() calls:

  • pyguymer3.geo.bufferSrc.buffer_CoordinateSequence() (this is the only function that actually does any buffering, as evidenced by it not calling any other bufferSrc functions)

    • pyguymer3.geo._buffer_points_crudely()

    • pyguymer3.geo._points2polys()

    • pyguymer3.geo.fillin()

  • pyguymer3.geo.bufferSrc.buffer_LinearRing() calls:

    • pyguymer3.geo.bufferSrc.buffer_CoordinateSequence()

  • pyguymer3.geo.bufferSrc.buffer_LineString() calls:

    • pyguymer3.geo.bufferSrc.buffer_CoordinateSequence()

  • pyguymer3.geo.bufferSrc.buffer_MultiLineString() calls:

    • pyguymer3.geo.bufferSrc.buffer_LineString()

  • pyguymer3.geo.bufferSrc.buffer_MultiPoint() calls:

    • pyguymer3.geo.bufferSrc.buffer_Point()

  • pyguymer3.geo.bufferSrc.buffer_MultiPolygon() calls:

    • pyguymer3.geo.bufferSrc.buffer_Polygon()

  • pyguymer3.geo.bufferSrc.buffer_Point() calls:

    • pyguymer3.geo.bufferSrc.buffer_CoordinateSequence()

  • pyguymer3.geo.bufferSrc.buffer_Polygon() calls:

    • pyguymer3.geo.bufferSrc.buffer_LinearRing()

• pyguymer3.geo.fillin()

  • pyguymer3.geo.fillinSrc.fillin_CoordinateSequence() (this is the only function that actually does any filling in, as evidenced by it not calling any other fillinSrc functions)

    • pyguymer3.geo.calc_dist_between_two_locs()

    • pyguymer3.geo.great_circle()

  • pyguymer3.geo.fillinSrc.fillin_LinearRing() calls:

    • pyguymer3.geo.fillinSrc.fillin_CoordinateSequence()

  • pyguymer3.geo.fillinSrc.fillin_LineString() calls:

    • pyguymer3.geo.fillinSrc.fillin_CoordinateSequence()

  • pyguymer3.geo.fillinSrc.fillin_MultiLineString() calls:

    • pyguymer3.geo.fillinSrc.fillin_LineString()

  • pyguymer3.geo.fillinSrc.fillin_MultiPolygon() calls:

    • pyguymer3.geo.fillinSrc.fillin_Polygon()

  • pyguymer3.geo.fillinSrc.fillin_Polygon() calls:

    • pyguymer3.geo.fillinSrc.fillin_LinearRing()

Copyright 2017 Thomas Guymer [1]

References

[1]

PyGuymer3, https://github.com/Guymer/PyGuymer3

Modules

add_GSHHG_map_underlay(ax, /, *[, ...])	Add an underlay to a Cartopy axis from the Global Self-Consistent Hierarchical High-Resolution Geography dataset
add_NE_map_underlay(ax, /, *[, background, ...])	Add an underlay to a Cartopy axis from Natural Earth.
add_OSM_map_background(ax, midLat, res, /, *)	Add OpenStreetMap map tiles as a background to a Cartopy axis.
add_annotation(ax, locLon, locLat, ...[, ...])	Add an annotation to a Cartopy axis.
add_axis(fg, /, *[, add_coastlines, ...])	Add either a global Robinson axis or an Orthographic axis centred above a point with optionally a field-of-view based on a circle around the point on the surface of the Earth
add_map_background(ax, /, *[, debug, ...])	Add an image of a map as a background to a Cartopy axis.
area(shape, /, *[, eps, level, nIter, ...])	Find the area of a shape.
buffer(shape, dist, /, *[, debug, eps, ...])	Buffer a shape
bufferSrc
calc_angle_between_two_locs(lon1_deg, ...)	Calculate the angle between two coordinates.
calc_dist_between_two_locs(lon1_deg, ...[, ...])	Calculate the distance between two coordinates.
calc_loc_from_loc_and_bearing_and_dist(...)	Calculate the location and reverse bearing from another location and a forward bearing and a distance.
check(shape, /, *[, prefix])	Check a shape
checkSrc
clean(shape, /, *[, debug, prefix, tol])	Clean a shape
cleanSrc
clipLatitude(lat, /)	Clip latitude to be between -90° (inclusive) and +90° (inclusive)
create_image_of_points(pntLons, pntLats, ...)	Save a PNG map of a sequence of points
create_map_of_points(pntLons, pntLats, ...)	Save a PNG map of a sequence of points
en2ll(shape1, /, *[, debug, prefix, tol])	Transform from Eastings/Northings to Longitudes/Latitudes
en2llSrc
extract_lines(shape, /, *[, onlyValid])	Extract the LineStrings from the shape
extract_points(shape, /, *[, onlyValid])	Extract the Points from the shape
extract_polys(shape, /, *[, onlyValid, repair])	Extract the Polygons from the shape
fillin(shape, fill, /, *[, debug, eps, ...])	Fill in a shape
fillinSrc
find_middle_of_great_circle(lon1_deg, ...)	Calculate the middle of the great circle that connects two coordinates.
find_middle_of_locs(lons, lats, /, *[, ...])	Find the middle of some locations
find_middle_of_locsSrc
find_min_max_dist_bearing(midLon, midLat, ...)	Find the bearing which points towards the minimum maximum distance to some locations
find_point_on_great_circle(frac, lon1_deg, ...)	Calculate an arbitrary point on the great circle that connects two coordinates.
getRecordAttribute(record, attribute, /, *)	Get an attribute of a Shapefile record
great_circle(lon1, lat1, lon2, lat2, /, *[, ...])	Calculate the great circle that connects two coordinates.
ll2en(shape1, /, *[, debug, prefix, tol])	Transform from Longitudes/Latitudes to Eastings/Northings
ll2enSrc
ll2mer(shape1, /, *[, debug, prefix, tol])	Transform from Longitudes/Latitudes to Mercator fractions
ll2merSrc
max_dist(lons, lats, midLon, midLat, /, *[, ...])
max_distSrc
mer2ll(shape1, /, *[, debug, prefix, tol])	Transform from Mercator fractions to Longitudes/Latitudes
mer2llSrc
min_dist(lons, lats, midLon, midLat, /, *[, ...])
min_distSrc
wrapLongitude(lon, /)	Wrap longitude to be between -180° (inclusive) and +180° (exclusive)