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CFAST Output Comparison Method and Its Use in Comparing Different CFAST Versions.



D M. Alvord


A multiple step method was developed to compare the output of CFAST simulations, produced either by the same version of CFAST, or by different versions of the model. Scenarios to be compared are run with CFAST before the method is used, producing files containing a history of the model results. The first step of the comparison method produces a text file of important output variables from each of these history files, corresponding to significant fire phenomena occurring during the course of each fire simulation. The next step of the method is used to compare two such text files, and store their differences. Finally, the last step summarizes the difference information found in one or more files from the previous step. The comparison method can be used to find differences between CFAST runs, and to track changes in the CFAST model and detect if they perform as anticipated. It has been used to compare three CFAST versions through use of a documented set of test files. This set will change as improvements are made to the model. The method can be used to find the effects whenever any substantial changes are made to CFAST, and is a useful tool for any user of the model. This report describes the comparison method in sufficient detail to serve as a user's guide, provides examples of the method's use, and discusses ways in which it could be improved and generalized.
NIST Interagency/Internal Report (NISTIR) - 5705
Report Number


computer models, computer programs, comparison, differences, fire models, fire research, predictive models, tests


Alvord, D. (1995), CFAST Output Comparison Method and Its Use in Comparing Different CFAST Versions., NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 18, 2024)


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Created August 1, 1995, Updated November 10, 2018