Hi! I am working on Macbook pro with basemap, but I met some issues. When I try to pip install basemap, there is something wrong with this. But I have already brew install geos, what's wrong? Thanks!

I install basemap with the command conda install basemap -c conda-forge

but

from mpl_toolkits.basemap import Basemap

returns:

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-23-212c45f90d40> in <module>()
----> 1 from mpl_toolkits.basemap import Basemap
      2 #import matplotlib.pyplot as plt
      3 import numpy as np

/srv/conda/lib/python3.6/site-packages/mpl_toolkits/basemap/__init__.py in <module>()
    144 
    145 # create dictionary that maps epsg codes to Basemap kwargs.
--> 146 pyproj_datadir = os.environ['PROJ_LIB']
    147 epsgf = open(os.path.join(pyproj_datadir,'epsg'))
    148 epsg_dict={}

/srv/conda/lib/python3.6/os.py in __getitem__(self, key)
    667         except KeyError:
    668             # raise KeyError with the original key value
--> 669             raise KeyError(key) from None
    670         return self.decodevalue(value)
    671 

KeyError: 'PROJ_LIB'

I am trying to scatter plot on maps with nonzero middle longitude, but the areas where the map is "wrapped" are not plotted.

My test script:

from mpl_toolkits.basemap import Basemap import matplotlib.pyplot as plt

m = Basemap(lon_0=160) m.fillcontinents()

for x in range(-179, 179):
px1, py1 = m(x, x/4.0) m.scatter(px1,py1, zorder=3)

plt.show()

If lon_0 is zero it works fine but with non-zero lat_0 some areas are not plotted.

It seems like the m(lon,lat) is not wrapping the points, the points I expect to wrap are negative in px1?

Or am I missing some transformation step?

Dear community, and possible people suffering as well,

I also have struggles for installing basemap, especially with python3.6 (default shipped with Ubuntu 18.04) After several tries like using cartopy, using apt install to install cartopy and basemap. None of them works quickly for python3.6.

In the end it works for this "simple" way:

1. Installing pyproj (3.0.0) by python3 -m pip install pyproj==3.0
2. installing matplotlib by python3 -m pip install matplotlib==3.3.3
3. downloading the basemap 1.2.2 version and install also by python3 -m pip install . in the basemap untar folder.

Hope this helps.

I tried a simple map and add some arcgisimage, but it failed.

Here is the code:

m=Basemap(projection='cyl',llcrnrlon=-90,llcrnrlat=30,urcrnrlon=-60,urcrnrlat=60)
m.arcgisimage(verbose=True)
plt.show()

And the error:

Traceback (most recent call last):
  File "/home/bastien/PycharmProjects/untitled/rider_analysis.py", line 55, in <module>
    m.arcgisimage(verbose=True)
  File "/usr/lib/python3.5/site-packages/mpl_toolkits/basemap/__init__.py", line 4270, in arcgisimage
    return self.imshow(imread(urllib.request.urlopen(basemap_url)),origin='upper')
  File "/usr/lib/python3.5/site-packages/matplotlib/image.py", line 1326, in imread
    return handler(fname)
SystemError: <built-in function read_png> returned NULL without setting an error

Process finished with exit code 1

After debugging around, I found that imread does not like http.request.HttpResponse, but works fine with file path.

Regards,

Bastien

Environment macOS Monterey Version 12.1 Chip Apple M1 Max Python 3.10.1

With the goes library as below

brew install geos
export $GEOS_DIR=/opt/homebrew/Cellar/geos/3.10.2/
/opt/homebrew/Cellar/geos/3.10.2/

I tried to install basemap following the comments on #531

poetry add basemap
# same symptom with pip

but installation failed with error

EnvCommandError

  Command ['/Users/yuujin/Workspace/.venv/bin/pip', 'install', '--no-deps', 'file:///Users/yuujin/Library/Caches/pypoetry/artifacts/b1/eb/1a/6b80b1e92c9b7b023c7d118d790f51ffc701b0c0e5f1e87b6959ab1b89/basemap-1.3.1.zip'] errored with the following return code 1, and output: 
  Processing /Users/yuujin/Library/Caches/pypoetry/artifacts/b1/eb/1a/6b80b1e92c9b7b023c7d118d790f51ffc701b0c0e5f1e87b6959ab1b89/basemap-1.3.1.zip
    Preparing metadata (setup.py): started
    Preparing metadata (setup.py): finished with status 'error'
    ERROR: Command errored out with exit status 1:
     command: /Users/yuujin/Workspace/.venv/bin/python -c 'import io, os, sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/setup.py'"'"'; __file__='"'"'/private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/setup.py'"'"';f = getattr(tokenize, '"'"'open'"'"', open)(__file__) if os.path.exists(__file__) else io.StringIO('"'"'from setuptools import setup; setup()'"'"');code = f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-pip-egg-info-548b08zr
         cwd: /private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/
    Complete output (9 lines):
    /private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/setup.py:52: RuntimeWarning: Cannot find GEOS library and/or headers in standard locations ('/opt/homebrew/Cellar/geos/3.10.2/'). Please install the corresponding packages using your software management system or set the environment variable GEOS_DIR to point to the location where GEOS is installed (for example, if 'geos_c.h' is in '/usr/local/include' and 'libgeos_c' is in '/usr/local/lib', then you need to set GEOS_DIR to '/usr/local'
      warnings.warn(" ".join([
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/setup.py", line 149, in <module>
        dev_requires = get_content("requirements-dev.txt", splitlines=True)
      File "/private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/setup.py", line 23, in get_content
        with io.open(path, encoding="utf-8") as fd:
    FileNotFoundError: [Errno 2] No such file or directory: '/private/var/folders/5r/0p5dh9vx78qbptqmcm3zmgdm0000gn/T/pip-req-build-diy_eywu/requirements-dev.txt'
    ----------------------------------------
  WARNING: Discarding file:///Users/yuujin/Library/Caches/pypoetry/artifacts/b1/eb/1a/6b80b1e92c9b7b023c7d118d790f51ffc701b0c0e5f1e87b6959ab1b89/basemap-1.3.1.zip. Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
  ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

Even there exist header and built binary 'geos_c.h' and 'libgeos_c' in $GEOS_DIR

The exception;

m.scatter(x, y,50,marker='o',color='g',latlon=True, zorder=10)
  File Anaconda\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 536, in with_transform
    x = self.shiftdata(x)
  File "Anaconda\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 4777, in shiftdata
    if itemindex:
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

There seems to be a mismatch when using latlon that shiftdata does not expect. This can be mitigated by getting the projection coordinates before applying the operation; example below.

from mpl_toolkits.basemap import Basemap
import numpy as np
import matplotlib.pyplot as plt

def valueError():
    m = Basemap(projection='robin',lon_0=115,resolution='c')
    m.drawcoastlines()
    m.fillcontinents(color='sienna',lake_color='aqua')
    m.drawmapboundary(fill_color='lightsteelblue')

    x = [-5.435, -6.660817, -119.2511944, 17.719833]
    y = [36.136, 4.746717, 39.4030278, -14.657583]
    m.scatter(x, y,50,marker='o',color='g',latlon=True, zorder=10)
    plt.show()

def works():
    m = Basemap(projection='robin',lon_0=115,resolution='c')
    m.drawcoastlines()
    m.fillcontinents(color='sienna',lake_color='aqua')
    m.drawmapboundary(fill_color='lightsteelblue')
    x = [-5.435, -6.660817, -119.2511944, 17.719833]
    y = [36.136, 4.746717, 39.4030278, -14.657583]

    x,y = m(x,y)
    m.scatter(x, y,50,marker='o',color='g',latlon=False, zorder=10)
    plt.show()

def main():
    works()
    valueError()

if __name__ == '__main__':
    main()

Bug report

Bug summary

Basemap cannot work when I update the matplotlib to the new version 3.0.1.

Code for reproduction

import matplotlib.pyplot as plt
import numpy as np
from mpl_toolkits.basemap import Basemap

outfile = r'E:\wrong.tif'

# read in data on lat/lon grid.
# data from https://github.com/matplotlib/basemap/tree/master/examples
hgt = np.loadtxt(r'E:\tmp\basemap\500hgtdata.gz')
lons = np.loadtxt(r'E:\tmp\basemap\500hgtlons.gz')
lats = np.loadtxt(r'E:\tmp\basemap\500hgtlats.gz')
lons, lats = np.meshgrid(lons, lats)

mnh = Basemap(lon_0=-105, boundinglat=20.,
              resolution='c', area_thresh=10000., projection='nplaea')
xnh, ynh = mnh(lons, lats)
CS = mnh.contour(xnh, ynh, hgt, 15, linewidths=0.5, colors='k')
CS = mnh.contourf(xnh, ynh, hgt, 15, cmap=plt.cm.Spectral)

mnh.drawcoastlines(linewidth=0.5)
delat = 30.
circles = np.arange(0., 90., delat).tolist() + \
          np.arange(-delat, -90, -delat).tolist()
mnh.drawparallels(circles, labels=[1, 0, 0, 0])
delon = 45.
meridians = np.arange(0, 360, delon)
mnh.drawmeridians(meridians, labels=[1, 0, 0, 1])
plt.title('NH 500 hPa Height (cm.Spectral)')

# colorbar on bottom.
mnh.colorbar(pad='5%')
plt.savefig(outfile, dpi=300, bbox_inches='tight')  
plt.show()

Actual outcome

# If applicable, paste the console output here

Traceback (most recent call last):
  File "E:/MyWork/code/python/psta/tmp.py", line 20, in <module>
    CS = mnh.contour(xnh, ynh, hgt, 15, linewidths=0.5, colors='k')
  File "D:\Python36\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 542, in with_transform
    return plotfunc(self,x,y,data,*args,**kwargs)
  File "D:\Python36\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 3566, in contour
    self._restore_hold(ax)
  File "D:\Python36\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 3229, in _restore_hold
    ax._hold = self._tmp_hold
AttributeError: can't set attribute

Expected outcome

Matplotlib version

• Operating system: Windows 10 x64
• Matplotlib version: 3.0.1
• Matplotlib backend (print(matplotlib.get_backend())): module://backend_interagg
• Python version: 3.6.6
• Jupyter version (if applicable): None
• basemap version: 1.2.0
• PyCharm version: 2018.2.4

I install matplotlib and basemap from https://www.lfd.uci.edu/~gohlke/pythonlibs.

Install libgeos using apt would probably save almost 4 minutes of build time. There is also a newer version of GEOS already packaged.

In .travis.yaml replace the compiling of libgeos with this:

addons:
  apt:
    packages:
    - libgeos-3.3.8

Here are the docs for APT on Travis.

I'm putting this here until I can get PR #234 working and merged.

Defining a Basemap in geostationary projection,

>>> from mpl_toolkits.basemap import Basemap
>>> Basemap(projection='geos', lon_0=0)

fails in basemap-1.1.0 with the following error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "...lib/python2.7/site-packages/mpl_toolkits/basemap/__init__.py", line 1109, in __init__
self._readboundarydata('gshhs',as_polygons=True)
  File "...lib/python2.7/site-packages/mpl_toolkits/basemap/__init__.py", line 1241, in _readboundarydata
raise ValueError('%s projection cannot cross pole'%(self.projection))
ValueError: geos projection cannot cross pole

This is for issue #235 . Using the APT binary versions of libgeos speed up Travis test times by eliminating some of the compiling. Also, dashes were added to install steps to show the install timea for dependent packages.

In testing, the overall Travis test time is about the same. It adds two additional tests builds.

The way this is setup APT installs these period. setup.py does not have a way to force local libgeos install, which is probably not a bad thing.

Hi matplotlib/basemap!

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Questions? Check out the FAQ below!

FAQ

Documentation Link

No response

Problem

Basemap is deprecated and all users should be using Cartopy.

In 2020, https://github.com/matplotlib/matplotlib/pull/16495 removed references to Basemap from matplotlib's documentation. Is it now time to more clearly mark Basemap as deprecated on https://matplotlib.org/basemap/ ?

I do see that the deprecation is described at the bottom of https://matplotlib.org/basemap/ but:

1. this statement can be missed (I recently met a user that had missed the information);
2. the statement is only on the main Basemap doc page, not in pages linked from there (random example https://matplotlib.org/basemap/users/mapsetup.html).

Suggested improvement

Place bold/red warning statements on all pages of the Basemap documentation, starting from https://matplotlib.org/basemap/

As per https://stackoverflow.com/questions/74433797/fill-oceans-in-high-resolution-to-hide-low-resolution-contours-in-basemap I'm trying to fill the ocean with high resolution polygons to mask out some low resolution filled contours. Unfortunately the built-in land sea mask of basemap is not enough for zoomed in regions.

For this reason I'm trying to fill the ocean shapefiles of natural earth https://www.naturalearthdata.com/downloads/10m-physical-vectors/ using the following code

m = Basemap(projection='merc',
                llcrnrlat=36,
                urcrnrlat=47,
                llcrnrlon=6,
                urcrnrlon=19,
                lat_ts=20,
                resolution='h')

shp = m.readshapefile('../input/shapefiles/ne_10m_ocean/ne_10m_ocean',
                'ne_10m_ocean', drawbounds = True)
patches   = []
for info, shape in zip(m.ne_10m_ocean_info, m.ne_10m_ocean):
    patches.append( Polygon(np.array(shape), True) )
        
plt.gca().add_collection(PatchCollection(patches, facecolor= 'red', edgecolor='k', linewidths=1., zorder=2))

This, however, does also fill some of the major islands with the same color of the ocean, as the following figure shows.

Am I doing something wrong? I checked the original shapefile and the polygons seem to be well defined. Here is the same plot done with Cartopy

I remember seeing this already a long time ago but I never managed to solve it.

I'm plotting a map using this

m = Basemap(projection='merc',
                llcrnrlat=extents[2],
                urcrnrlat=extents[3],
                llcrnrlon=extents[0],
                urcrnrlon=extents[1],
                lat_ts=20,
                resolution='h')

m.fillcontinents(color='lightgray', lake_color='#2081C3', zorder=1)
m.drawlsmask(land_color=(0, 0, 0, 0), ocean_color='#2081C3',
                 resolution='f', lakes=True, zorder=2, grid=1.25)

ax = plt.gca()

m.drawcountries(linewidth=0.8)
m.drawcoastlines()

m.readshapefile(f'{SHAPEFILES_DIR}/ITA_adm_shp/ITA_adm1',
                        'ITA_adm1', linewidth=0.8, color='black', zorder=5)

but some countries (like Switzerland) don't show up.

Weirdly enough when centering the projection over France Switzerland shows up

In the context of fixing current issues within basemap, one easy step is to use static analysis tools, since they can catch the most evident problems.

I open this issue as a reminder to enable flake8 in the development workflow; flake8 will catch the most evident code mistakes, and it will also give advice on changes that will make the code more pep8-compliant. Enabling pylint at this moment is not recommended, because it will complain too much.