CSpace: an integrated workplace for the graphical and algebraic analysis of phase assemblages on 32-bit wintel platforms

CSpace is a program for the graphical and algebraic analysis of composition relations within chemical systems. The program is particularly suited to t he needs of petrologists, but could also prove useful for mineralogists, ge ochemists and other environmental scientists. A few examples of what can be accomplished with CSpace are the mapping of compositions into some desired set of system/phase components, the estimation of reaction/mixing coeffici ents and assessment of phase-rule compatibility relations within or between complex mineral assemblages. The program also allows dynamic inspection of compositional relations by means of barycentric plots. CSpace provides an integrated workplace for data management, manipulation and plotting. Data m anagement is done through a built-in spreadsheet-like editor, which also ac ts as a data repository for the graphical and algebraic procedures. Algebra ic capabilities are provided by a mapping engine and a matrix analysis tool , both of which are based on singular-value decomposition. The mapping engi ne uses a general approach to linear mapping, capable of handling determine d, underdetermined and overdetermined problems. The matrix analysis tool is implemented as a task "wizard" that guides the user through a number of st eps to perform matrix approximation (finding nearest rank-deficient models of an input composition matrix), and inspection of null-reaction space rela tionships (i.e. of implicit linear relations among the elements of the comp osition matrix). Graphical capabilities are provided by a graph engine that directly links with the contents of the data editor. The graph engine can generate sophisticated 2D ternary (triangular) and 3D quaternary (tetrahedr al) barycentric plots and includes features such as interactive re-sizing a nd rotation, on-the-Ay coordinate scaling and support for automated drawing of tie lines. (C) 2000 Published by Elsevier Science Ltd.