2.3.8.13. vacumm.misc.grid.basemap – mpl_toolkits.basemap related

2.3.8.14. Overview

Attributes:

GSHHS_RESLIST

RSHPERE_WGS84

gshhs_reslist

Functions:

cache_map() cached_map() clean_cache() create_map()

get_map() get_map_dir() get_proj()

gshhs_autores() merc() reset_cache()

Classes:

GSHHS_BM

2.3.8.15. Content

Inheritance diagram:  

Utilities derived from mpl_toolkits.basemap

class GSHHS_BM(input=None, clip=None, sort=True, reverse=True, proj=False, **kwargs)

Bases: vacumm.misc.io.Shapes

Shoreline from USGS using Basemap

Initialized with a valid Basemap instance with resolution not equal to None, or thanks to arguments passed to create_mapplot.map()

• input: Basemap or Shapes instance [default: None]

INPUT_MULTIPOINTS = 8

INPUT_POINTS = 1

INPUT_POLYGONS = 5

INPUT_POLYLINES = 3

LINE = 1

LINES = 1

POINT = 0

POINTS = 0

POLY = 2

POLYGON = 2

POLYGONS = 2

POLYS = 2

clip(zone, copy=True, sort=True, reverse=True, **kwargs)

Clip to zone

Params:

• zone: [xmin, ymin, xmax, ymax]
• copy, optional: If True, make a copy of current instance, else simply rehandled the list of shapes.
• If copy==True, Other parameters are passed to the initialization of the new instance.

get_data(key=None, proj=None)

Get the numeric version of the list of geos objects (polygons, etc)

Param:

• key: A slice selector applied to the list.
• proj: True, or a callable to project or re-project coordinates.

get_map()

Return the associated basemap instance if set

get_points(key=None, split=True, proj=None)

Get all the points from all the shapes as a tuple (x,y)

get_shapes(key=None, proj=None)

Get the list of geos objects (polygons, etc)

Param:

• key: A slice selector applied to the list.
• proj: True, or a callable to project or re-project coordinates.

get_type()

Return the type of shapes

• POINTS = Points,
• LINES = LineStrings = PolyLines
• POLYGONS = Polygons

get_xy(key=None, proj=None)

Shortcut to get_points(split=false)

is_type(type)

Check type

Example:

>>> self.is_type(self.POLYS)

plot(select=None, ax=None, fill=None, points=False, lines=True, fillcolor=None, color='k', s=None, linewidth=None, m=None, show=True, alpha=1, autoscale=True, title=None, **kwargs)

Plot shapes

Params:

• select, optional: argument for selecting shapes in the list [defaul: None].
• fill, optional: Force filling (True/False), else guessed from shpe type, ie filling for polygons only [default: None]
• ax, optional: Axes instance.
• m, optional: Map instance (created with map2()) or a Basemap instance.
• points, optional: Plots shapes as points.
• lines, optional: Plot shapes as lines (if a of type POINTS).
• fill_<params>, optional: <param> is passed to PolyCollection.
• lines_<params>, optional: <param> is passed to LineCollection or to PolyCollection.
• points_<params>, optional: <param> is passed to scatter.
• m_<params>, optional: <param> is passed to map2 if m is True.
• autoscale, optional: Autoscale axis limits?

resol(deg=True)

Compute the mean “resolution” of the shapes based on the first shape

• deg:

  • if False: return a resolution in meters has a the median distance between points
  • if True: return the median distance between points as a resolution in degrees (xres,yres)

sort(reverse=True)

Sort shapes according to their surface or length

• reverse: If True, greater polygons are first [default: True]

sorted()

xy

XY coordinates as a (2,npts) array

GSHHS_RESLIST = ['f', 'h', 'i', 'l', 'c']

GSHHS shorelines letters

RSHPERE_WGS84 = (6378137.0, 6356752.3141)

Earth radius of wgs84 ellipsoid

cache_map(m, mapdir=None)

Cache a map if still not cached

cached_map(m=None, mapdir=None, verbose=False, **kwargs)

Check if we have a cached map

• m: A Basemap instance [Default: None]
• mapdir: Where are stored the cached maps. If None, matplotlib.get_configdir() is used as a parent directory, which is the matplotlib configuration directory (~/.matplotlib undex linux), and basemap/cached_maps as the subdirectory.

Example:

>>> m = cached_map(lon_min=-5, lon_max=6, lat_min=40, lat_max=50, projection='lcc', resolution='f')
>>> m = cached_map(m) # Does only caching of map

clean_cache(mapdir=None, maxsize=None)

Clean cache directory by checking its size

Params:

• mapdir, optional: Directory where maps are cached
• maxsize, optional: Maximal size of directory in bytes. Default value from [vacumm.misc.grid.basemap]max_cache_size configuration value.

create_map(lon_min=-180.0, lon_max=180.0, lat_min=-90.0, lat_max=90.0, projection='cyl', resolution='auto', epsg=None, lon_center=None, lat_center=None, lat_ts=None, zoom=None, ax=None, overlay=False, fullscreen=False, nocache=False, cache_dir=None, **kwargs)

Generic creation of a Basemap instance with caching

Todo

Merge get_map() with create_map()

get_map(gg=None, proj=None, res=None, auto=False, **kwargs)

Quickly create Basemap instance

Params:

• gg, optional: cdms grid or variable, or (xx,yy).
• res, optional: Resolution.
• proj, optional: Projection [default: None->’merc’]
• auto, optional: If True, get geo specs according to grid. If False, whole earth. If None, auto = res is None.

Todo

Merge with create_map()

get_map_dir(mapdir=None)

Get the directory where cqched maps are stored

get_proj(gg=None, proj=None, **kwargs)

Setup a default projection using x,y coordinates and Proj or basic_proj()

Projection is set by default to “basic”.

Params:

• gg, optional: Grid or coordinates (see get_xy()). If not provided, lon bounds are set to (-180,180) and lat bounds to (-89.99,89.99).
• Other keywords are passed to Proj. One of them is the projection type, which defaults to configuration option [vacumm.misc.grid.basemap] proj.

Return:

A mpl_toolkits.basemap.proj.Proj instance or basic_proj()

Examples:

>>> proj = get_proj(sst.getGrid(), proj='laea')
>>> x, y = proj(lon, lat)

>>> proj = get_proj((lon, lat))
>>> xx, yy = N.meshgrid(lon, lat)
>>> xx, yy = proj(xx, yy)
>>> print proj(xx, yy, inverse=True)

>>> proj = get_proj(R=6000000.)

gshhs_autores(lon_min, lon_max, lat_min, lat_max, asindex=False, shift=None)

Guess best resolution from lon/lat bounds

merc(lon=None, lat=None, **kwargs)

Mercator map

• Extra keywords are passed to mpl_toolkits.basemap.Basemap
• lon: Longitudes to define llcrnrlon and urcrnrlon
• lat: Latitudes to define lat_ts, llcrnrlat and urcrnrlat

reset_cache(mapdir=None)

Remove all cached maps