Introducing Stripy
Geodynamicists from Sydney and Australian National universities have developed Stripy, a software module that allows scientists to efficiently place GIS ‘wrapping paper’ around the spherical Earth ‘present’. This is the first module to be built for a common scientific programming language like Python, that supports such ‘wrapping’, or mapping features. Here, developer Dr Ben Mather explains Stripy’s key functions for the AuScope Earth modelling community.
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Article originally published by Auscope.
Do these questions apply to you?
Have you ever been given a dataset with random points distributed all over the globe that you need to interpolate to a grid? Has somebody sent you a seismic tomography file defined on a seven-times refined icosahedral triangulation and you need to make a global map? Ever needed to fit a smooth surface through a set of points in the plane or on the globe?
The triangulation of scattered points is a common problem in geospatial applications where longitudinal and latitudinal data need to be meshed. Typical applications include the calculation of neighbour relationships, interpolate, smooth, or find the derivatives of a surface. Until now, there have been no packages available for a prevalent scientific programming language, such as Python, that support these features.
The Stripy solution
Introducing Stripy: a lightweight object-oriented Python package for building meshes from unstructured data on the sphere. A series of example meshes are provided including such classics as icosahedral, octahedral, and soccer ball meshes.
Stripy includes the following functionality:
- Spherical and Cartesian triangulation of scattered points.
- Construction of Cartesian and Spherical meshes.
- Nearest-neighbour, linear, and hermite cubic interpolation.
- Evaluation of derivatives.
- Smoothing operations.
- Mesh refinement on line segments / triangle centroids.
- Fast point location with k-d tree interface with angular separation metric on the sphere.
In case you weren’t already sold, all these features are also available in Cartesian coordinates. Stripy is bundled with a linked collection of Jupyter notebooks that can act as a user guide and an introduction to the package. The notebooks are split into matching sets for spherical and Cartesian triangulations.
Download Stripy, or make it better
Stripy is a member of the Underworld family of open-source software packages, and is freely available for download by multiple installation methods on GitHub. If you get stuck and need assistance, please open a GitHub issue. If you want to contribute in some way to the project, please see our contributions guide.