@@ -7,12 +7,49 @@ diffpy.pdfmorph - Tools for manipulating and comparing PDF profiles.
77| Software version |release|.
88| Last updated |today|.
99
10+ Introduction
11+ ++++++++++++
12+
13+ ``PDFmorph `` is a Python package that increases the insight
14+ researchers can obtain from measured atomic pair distribution functions
15+ (PDFs) in a model-independent way. It was designed to help a
16+ researcher answer the question: "Has my material undergone a phase
17+ transition between these two measurements?"
18+
19+ One approach is to compare the two PDFs in a plot and view the
20+ difference curve underneath. However, significant signal can be seen in
21+ the difference curve from benign effects such as thermal expansion (peak
22+ shifts) and increased thermal motion (peak broadening) or a change in
23+ scale due to differences in incident flux, for example. ``PDFmorph `` will
24+ do its best to correct for these benign effects before computing and
25+ plotting the difference curve. One measured PDF (typically that
26+ collected under higher temperature) is identified as the target PDF and
27+ the second PDF is then morphed by "stretching" (changing the r-axis to
28+ simulate a uniform lattice expansion), "smearing" (broadening peaks
29+ through a uniform convolution to simulate increased thermal motion), and
30+ "scaling" (self-explanatory). PDFmorph will vary the amplitude of the
31+ morphing transformations to obtain the best fit between the morphed and
32+ the target PDFs, then plot them on top of each other with the difference
33+ plotted below.
34+
35+ There are also a few other morphing transformations in the program.
36+ If no morphing transformation is specified, ``PDFmorph `` will return just
37+ the plotted PDFs.
38+
39+ Finally, we note that though ``PDFmorph `` should work on other spectra
40+ that are not PDFs, it has not been extensively tested beyond the PDF.
41+
42+ To get started, please download our :download: `user manual <../manual/pdfmorph.pdf >`
43+ or visit the :ref: `quick_start `.
44+
1045=======
1146Authors
1247=======
1348
14- diffpy.pdfmorph is developed by Billinge Group
15- and its community contributors.
49+ ``PDFmorph `` is developed by members of the Billinge Group at
50+ Columbia University and Brookhaven National Laboratory including
51+ Christopher L. Farrow, Christopher J. Wright, Pavol Juhás, Chia-Hao
52+ (Timothy) Liu, S. Matthew Román, and Simon J. L. Billinge.
1653
1754For a detailed list of contributors see
1855https://github.com/diffpy/diffpy.pdfmorph/graphs/contributors.
@@ -30,6 +67,7 @@ Table of contents
3067.. toctree ::
3168 :titlesonly:
3269
70+ quickstart
3371 license
3472 release
3573 Package API <api/diffpy.pdfmorph >
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