Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #573 from mantidproject/11541_fabada_documentation
Add a documentation page for FABADA
- Loading branch information
Showing
1 changed file
with
70 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,70 @@ | ||
.. _FABADA: | ||
|
||
FABADA | ||
====== | ||
|
||
FABADA is a fitting algorithm for Bayesian data analysis, the theory of which is | ||
detailed here: http://dx.doi.org/10.1088/1742-6596/325/1/012006 | ||
|
||
This documentation covers details of it's implementation in Mantid. | ||
|
||
Important Notes | ||
--------------- | ||
|
||
Currently in order to use FABADA the cost function must be set to Least Squares. | ||
|
||
The values for ChainLength and MaxIterations should be set to relatively high | ||
values where :math:`MaxIterations > 2 * ChainLength` (e.g. MaxIterations = 20^6 | ||
and ChainLength = 10^6). | ||
|
||
Currently the starting values used for each parameter are required to be a | ||
fairly good estimate of the actual value, in the event that a parameter is not | ||
estimated to sufficient accuracy convergence of the parameters will not be | ||
reached and an error message will inform of the unconverged parameters. | ||
|
||
FABADA Specific Parameters | ||
-------------------------- | ||
|
||
ChainLength | ||
Number of steps done by the algorithm once all of the parameters have | ||
converged. | ||
|
||
StepsBetweenValues | ||
Specifies interval at which to record parameter and cost function values in | ||
the chain outputs. | ||
|
||
ConvergenceCriteria | ||
The threshold variation in the cost function due to the change in a parameter | ||
under which it is assumed that the parameter has reached convergence. | ||
|
||
JumpAcceptanceRate | ||
The desired percentage of acceptance for new parameters (typically 0.666) | ||
|
||
FABADA Specific Outputs | ||
----------------------- | ||
|
||
Probability Density Function for each fitted parameter and the cost function. | ||
This is output as a :ref:`MatrixWorkspace`. | ||
|
||
Chains | ||
The value of each parameter and the cost function for each step taken. | ||
This is output as a :ref:`MatrixWorkspace`. | ||
|
||
ConvergedChain | ||
A subset of Chains containing only the section after which the parameters have | ||
converged. | ||
This records the parameters at step intervals given by StepsBetweenValues. | ||
This is output as a :ref:`MatrixWorkspace`. | ||
|
||
CostFunctionTable | ||
Table containing the minimum and most probable values of the cost function as | ||
well as their reduced values. | ||
This is output as a TableWorkspace. | ||
|
||
Parameters | ||
Similar to the standard parameter table but also includes left and right | ||
errors for each parameter (cost function is not included). | ||
This is output as a TableWorkspace. | ||
|
||
.. categories:: Concepts |