Python's Role in VisIt

Cyrus Harrison,Harinarayan Krishnan

doi:10.25080/majora-54c7f2c8-004

Abstract

VisIt is an open source, turnkey application for scientific data analysis and visualization that runs on a wide variety of platforms from desktops to petascale class supercomputers. VisIt’s core software infrastructure is written in C++, however Python plays a vital role in enabling custom workflows. Recent work has extended Python’s use in VisIt beyond scripting, enabling custom Python UIs and Python filters for low-level data manipulation. The ultimate goal of this work is to evolve Python into a true peer to our core C++ plugin infrastructure. This paper provides an overview of Python’s role in VisIt with a focus on use cases of scripted rendering, data analysis, and custom application

Highlights

VisIt [VisIt05], like EnSight [EnSight09] and ParaView [ParaView05], is an application designed for post processing of mesh based scientific data
This paper provides an overview of how VisIt leverages Python in its software architecture, outlines these two recent Python feature enhancements, and introduces several examples of use cases enabled by Python
VisIt uses a component-based architecture where the Python command line interface, the graphical user interface, and the viewer exist as separate applications that communicate over sockets

Summary

Introduction

VisIt [VisIt05], like EnSight [EnSight09] and ParaView [ParaView05], is an application designed for post processing of mesh based scientific data. The interface provides access to all features available through VisIt’s GUI It includes support for macro recording of GUI actions to Python snippets and full control of windowless batch processing. While Python has always played an important scripting role in VisIt, two recent development efforts have greatly expanded VisIt’s Python capabilities: 1) We support custom UI development using Qt via PySide [PySide]. This allows users to embed VisIt’s visualization windows into their own Python applications. 2) We recently enhanced VisIt by embedding Python interpreters into our data flow network pipelines This provides fine grained access, allowing users to write custom algorithms in Python that manipulate mesh data

Compute Engine

Python Client Interface

Accessing the Python Client Interface

Macro Recording

Custom Python UIs

Advanced Custom Python UI Examples

Python Filter Runtime

Conclusion