karta 0.6

Geospatial analysis in Python

Karta is a simple and fast framework for spatial analysis in Python.

Create vector geometries:

point = Point((-130.0, 52.0), crs=LonLatWGS84)

line = read_geojson("linedata.json")

polygon = Polygon([(-515005.78, -1301130.53),
                   (-579174.89, -1282271.94),
                   (-542977.83, -1221147.82),
                   (-437864.05, -1251641.55),
                   (-438160.72, -1252421.48),
                   (-437961.28, -1285314.00)],
                   crs=NSIDCNorth)

Perform simple queries:

point2 = Point((-25.0, 48.0), crs=LonLatWGS84)
point.distance(point2)          # Distance in geographical units

line.intersects(polygon)        # True or False

ch = polygon.convex_hull()      # Returns a new polygon
ch.to_shapefile("poly.shp")

Work with raster data:

grid = read_gtiff("landsat_scene.tif")  # Leverages GDAL

grid.profile(line)              # Collect data along a line

grid.resample(500.0, 500.0)     # Return a grid resampled at a new resolution

Karta works with Python 2.7 and Python 3.3+. Suggestions, bug reports, test cases, and pull requests are welcome.

DOCUMENTATION

See the online manual, the tutorial, or read the API documentation.

The manual can also be built offline using Sphinx by running make from the doc/ subdirectory. The documentation is built from source code docstrings and the example IPython notebooks, which are also reproduced in the Wiki. Building the documentation requires Sphinx, alabaster and numpydoc.

DEPENDENCIES

Required

• Python 2.7 or Python 3.3+

• numpy

• pyshp

• pyproj

• C-compiler

Recommended

• osgeo.gdal (for geotiff I/O)

• osgeo.osr (for coordinate system interchange)

• scipy

When installing from PyPI, Cython-compiled C source code is provided and will be automatically compiled to improve performance if a suitable C compiler is available.