@@ -10,38 +10,38 @@ Last updated |today|.
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Tool for unbiased peak extraction from atomic pair distribution functions.
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- The diffpy.srmise package is an implementation of the `ParSCAPE algorithm
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- <https://dx.doi.org/10.1107/S2053273315005276> `_ for peak extraction from
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- atomic pair distribution functions (PDFs). It is designed to function even
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- when *a priori * knowledge of the physical sample is limited, utilizing the
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- Akaike Information Criterion (AIC) to estimate whether peaks are
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- statistically justified relative to alternate models. Three basic use cases
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- are anticipated for diffpy.srmise. The first is peak fitting a user-supplied
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- collections of peaks. The second is peak extraction from a PDF with no (or
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- only partial) user-supplied peaks. The third is an AIC-driven multimodeling
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- analysis where the output of multiple diffpy.srmise trials are ranked.
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-
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- The framework for peak extraction defines peak-like clusters within the data,
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- extracts a single peak within each cluster, and iteratively combines nearby
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- clusters while performing a recursive search on the residual to identify
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- occluded peaks. Eventually this results in a single global cluster
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- containing many peaks fit over all the data. Over- and underfitting are
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- discouraged by use of the AIC when adding or removing (during a pruning step)
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- peaks. Termination effects, which can lead to physically spurious peaks in
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- the PDF, are incorporated in the mathematical peak model and the pruning step
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- attempts to remove peaks which are fit better as termination ripples due to
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- another peak.
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-
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- Where possible, diffpy.srmise provides physically reasonable default values
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- for extraction parameters. However, the PDF baseline should be estimated by
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- the user before extraction, or by performing provisional peak extraction with
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- varying baseline parameters. The package defines a linear (crystalline)
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- baseline, arbitrary polynomial baseline, a spherical nanoparticle baseline,
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- and an arbitrary baseline interpolated from a list of user-supplied values.
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- In addition, PDFs with accurate experimentally-determined uncertainties are
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- necessary to provide the most reliable results, but historically such PDFs
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- are rare. In the absence of accurate uncertainties an ad hoc uncertainty
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- must be specified.
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+ The diffpy.srmise package is an implementation of the `ParSCAPE algorithm
14
+ <https://dx.doi.org/10.1107/S2053273315005276> `_ for peak extraction from
15
+ atomic pair distribution functions (PDFs). It is designed to function even
16
+ when *a priori * knowledge of the physical sample is limited, utilizing the
17
+ Akaike Information Criterion (AIC) to estimate whether peaks are
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+ statistically justified relative to alternate models. Three basic use cases
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+ are anticipated for diffpy.srmise. The first is peak fitting a user-supplied
20
+ collections of peaks. The second is peak extraction from a PDF with no (or
21
+ only partial) user-supplied peaks. The third is an AIC-driven multimodeling
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+ analysis where the output of multiple diffpy.srmise trials are ranked.
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+
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+ The framework for peak extraction defines peak-like clusters within the data,
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+ extracts a single peak within each cluster, and iteratively combines nearby
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+ clusters while performing a recursive search on the residual to identify
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+ occluded peaks. Eventually this results in a single global cluster
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+ containing many peaks fit over all the data. Over- and underfitting are
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+ discouraged by use of the AIC when adding or removing (during a pruning step)
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+ peaks. Termination effects, which can lead to physically spurious peaks in
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+ the PDF, are incorporated in the mathematical peak model and the pruning step
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+ attempts to remove peaks which are fit better as termination ripples due to
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+ another peak.
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+
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+ Where possible, diffpy.srmise provides physically reasonable default values
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+ for extraction parameters. However, the PDF baseline should be estimated by
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+ the user before extraction, or by performing provisional peak extraction with
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+ varying baseline parameters. The package defines a linear (crystalline)
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+ baseline, arbitrary polynomial baseline, a spherical nanoparticle baseline,
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+ and an arbitrary baseline interpolated from a list of user-supplied values.
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+ In addition, PDFs with accurate experimentally-determined uncertainties are
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+ necessary to provide the most reliable results, but historically such PDFs
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+ are rare. In the absence of accurate uncertainties an ad hoc uncertainty
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+ must be specified.
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===================
@@ -81,7 +81,7 @@ Where next?
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tutorial/index.rst
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extending.rst
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======================================
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API
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======================================
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