Mr. Nicholas Schwarz (Argonne National Laboratory)
The APS continues to develop the *RSMap3D* software package, a general-purpose tool for reciprocal-space mapping. The tool allows users to examine the volume of collected data and select portions on which to apply transformations that convert detector pixel locations from diffractometer geometry to reciprocal-space units, and then map pixel data on to a 3D reciprocal-space grid. *RSMap3D* can map data acquired using 4- and 6-circle diffractometers, and with scans taken over angles or energy. The application presents a graphical interface for selecting the relevant parts of data to process via a 3D representation of the acquired data volume. Scan angle or energy data is usually read from data files generated by *spec*, while image data is often read from TIFF or HDF5 files. The core mapping routines utilize the *xrayutilities* package, which uses the OpenMP programming API to parallelize operations across multiple cores on a workstation for increased performance. Data too big to fit entirely into memory at one time is processed in smaller chunks and reassembled to form the final output volume, allowing users to process arbitrarily large input datasets. Once data is processed it may be used as input to further analysis workflows. Additionally, visualization is often an important part of the data analysis process. Data generated by *RSMap3D* is easily read by *ParaView*, an open source, high-performance tool for 3D data visualization and manipulation. *ParaView* allows the user to easily produce 3D contour plots, and make slices through the data using plane cuts or cuts on the surface of a defined sphere, for constant |qx, qy, qz| cuts, for example. Using *RSMap3D* in combination with sophisticated visualization tools enables APS staff and users to study large diffraction data quickly and effectively. *RSMap3D* is written in Python and relies heavily on the *xrayutilities*, *spec2nexus*, and *VTK* libraries. It is easily installed using the *pip* package management system, and runs on the Linux, OS X, and Windows platforms. *RSMap3D* is currently in regular use at the APS for time-resolved diffraction work at beamline 7-ID, for WA-XPCS analysis at beamline 8-ID, for data exploration with inelastic X-ray measurements at beamline 30-ID, for scattering and diffraction experiments at beamlines 33-BM and 33-ID, and for micro-diffraction analysis at beamline 34-ID. *Work supported by U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Mr. John Hammonds (Argonne National Laboratory)