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The TOPAS symbolic computation system

Coelho, A.A.; Evans, John S.O.; Evans, Ivana R.; Kern, A.; Parsons, S.


A.A. Coelho

Ivana R. Evans

A. Kern

S. Parsons



Computer algebra removes much of the drudgery from mathematics; it allows users to formulate models by using the language of mathematics and to have those models evaluated with little effort. This symbolic form of representation is often thought of as being separate to dedicated computational programs such as Rietveld refinement. These dedicated programs are often written in low level languages; they are relatively inflexible in what they do and modifying them to change functionality in a small manner is often a major programming task. This paper describes a symbolic system that is integrated into the dedicated Rietveld refinement program called TOPAS. The symbolic component allows large functional changes to be made at run time and with a relatively small amount of effort. In addition, the system as a whole reduces the programming complexity at the developmental stage.


Coelho, A., Evans, J. S., Evans, I. R., Kern, A., & Parsons, S. (2011). The TOPAS symbolic computation system. Powder Diffraction, 26(S1), S22-S25.

Journal Article Type Article
Publication Date 2011-12
Deposit Date May 6, 2013
Journal Powder Diffraction
Print ISSN 0885-7156
Electronic ISSN 1945-7413
Publisher Cambridge University Press
Peer Reviewed Peer Reviewed
Volume 26
Issue S1
Pages S22-S25