TraX was developed by Victor Levitin and Alexander Khibnik, Russian Academy of Sciences. A math coprocessor is recommended. Only pure mathematicians work with infinitely precise numbers. The numbers in science inevitably come with a degree of uncertainty, and in environmental sciences, with a substantial magnitude of it. In the latter case the value is unknown able, but the probability distribution is.
Inputs can be precise and uncertain numbers characterized by both ignorance and variability.
Many risk analyses compute with points estimates and treat the uncertainty associated with this estimates in simplistic way even though, in the absence of perfect knowledge, we can never be sure about the exact values of numbers used as input. Virtually all calculations, although seemingly precise, actually harbor some level of uncertainty. It provides a convenient environment for computing with numbers in which all uncertainties are carried forward automatically. Risk Calc for Microsoft Windows brings sophisticated methods of uncertainty analysis into reach of anymore who can do arithmetic on a calculator. Diseases such as cancer are often clumped together either in terms of their incidence in time or their distribution across space in ways that suggest a common environmental cause or a particular contagion process.