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Karta is a package for spatial analysis in Python. It streamlines data processing by providing efficient generic geographical types for vector and raster sources as well as a selection of analysis functions.

For example, read or 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")

Load and manipulate 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

The latest release is on PyPI (see Installation). Suggestions, bug reports, test cases, and pull requests are welcome.

The latest stable release is 0.7. The repository master branch is considered a moderately-unstable development branch.

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

The manual can be built offline using Sphinx. Building the documentation requires numpydoc.

• karta.crs: framework for coordinate reference systems and geodetic calculations

• karta.vector.geometry: geometry classes Point, Multipoint, Line, and Polygon with associated methods such as length, area, intersections, membership testing, convex hulls, and affine transformations

• karta.raster.grid: Grid classes including RegularGrid class (supporting CRS-aware clipping, sampling, profiling along vector tracks), and experimental WarpedGrid

• tests: unit tests, to be run with python tests/runtests.py

Karta provides a basic working interface to several of common file formats. Currently implemented are:

• vector
  • GeoJSON (r,w)
  • ESRI Shapefiles (via GDAL) (r,w)
  • GPS eXchange (GPX) (r,w)
• raster
  • GeoTiff (via GDAL) (r,w)
  • ESRI ASCII Grid (r,w)

Karta implements the Python __geo_interface__ attribute for vector geometries. This permits data to be exchanged between Karta and external modules that also implement __geo_interface__ (e.g. shapely, fastkml).

The easiest way to install in production is via pip. Installation requires a recent version of setuptools:

pip install -U setuptools

Then, to install the latest release from PyPI:

pip install karta

Building from source requires Cython:

pip install Cython

Then, clone the repository and install:

git clone https://github.com/fortyninemaps/karta.git karta
pip install -r karta/requirements.txt
pip install karta/

• numpy >= >1.7
• gdal >= 1.10
• pyproj >= 1.9
• blosc >= 1.2
• C99-compliant compiler

Karta supports Python 2.7 and Python 3.4+.

This software is provided under the MIT license.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.