RAMAS Software

| RAMAS Units Calculator | RAMAS Risk Calc | RAMAS Cast |

Units Calculator
Arithmetic Without Converting Units

        In science, all numbers have associated dimensions like meter/seconds for speed or kilograms for mass. Messing up the units is the most common error made in scientific calculations. RAMAS Units Calculator is designed to find and correct all such errors. Just as a spelling checker corrects your spelling, Units Calculator will correct your equations. However, just as a spelling checker will only check the spelling, not the structure of your sentence, Units Calculator will check your units and dimensions, but not the structure of the expression. But since this is the most common kind of error, it may be exactly what you need. Do not submit a paper or a laboratory report without checking your calculation with Units Calculator.

Apples and oranges   Units Calculator understands dimensional algebra and keeps you from adding apples and oranges, or meters and seconds. The Units Calculator also traps more subtle dimensional errors such as trying to raise a number to the "2 inch" power.

Automatic simplification   Units Calculator will automatically cancel units whenever possible and collect repeated units into squares, cubes, etc. You can also ask it to further simplify the units as much as possible without changing the dimension. However, it wouldn't change, for instance, hertz to reciprocal second or vice versa unless you want it to or unless it has to in order to solve your problem.

Support for SI   At a keystroke, the Units Calculator will convert an expression to conform with the metric system (SI) insofar as is possible. It converts expressions to conform with the latest specification of the Systéme international d'unitès. Although complete conversion may not always be possible (e.g., SI does not have a unit for bytes of information), it can convert most any expression to the nine base and supplementary units that make up SI.

Dimensions   Units Calculator understands that units represent underlying dimensional quantities. If you enter a unit's name and a question mark, the Units Calculator will tell you what it is the unit measures. It also understands deeper connections among dimensions, such as the fact that [force] is equivalent to [mass][length][time]^-2. It uses this knowledge to check expressions and to simplify your results. It uses this knowledge to check expressions and to simplify your results. It knows over 600 units measuring

Variables   You can assign values to variables to use in later expressions. Variables are specified by any name prefixed by an at-sign @. For instance, entering the assignment @sam = 10.6 m/sec gives a value to a variable with the name @sam. A special variable named @ always gets the last value computed. Sets of variables can be stored in external libraries and read into the calculator upon command.

Functions   Units Calculator can add, subtract, multiply, divide, exponentiate, take logs, powers, and all trigonometric functions, convert units, simplify, and compare values that you give it. It recognizes standard mathematical symbols and conventions. It supports the standard functions exp, ln, log10, abs, sgn (sign), sin, cos, tan, sct (secant), csc, ctn, asin (arc sine), acos, atan. The arguments for abs and sgn can have any units. The arguments for sin and the basic trigonometric functions must be angles (radians, degrees, etc.). Arguments for exp, ln, log10 and the inverse trigonometric functions must be dimensionless.

User accessibility   Aside from the SI units, all the definitions, synonyms and equivalences that the Units Calculator knows are accessible in ASCII files. You can change their spelling, enter your own nicknames for units, or define wholly new dimensions! Software is provided that checks that your changes are consistent.

Requirements:   IBM PC compatible; DOS 3+; 180K RAM; EGA or better video.
A version for Windows 95 is forthcoming.

Cost: See Software Price List and Ordering Information .

RAMAS Risk Calc 4.0
Risk Assessment with Uncertain Numbers

• What Risk Calc is for
• What Risk Calc can do
• New features in version 4.0
• Frequently asked questions
• Technical support
• Prices and ordering

• Probability bounds analysis
• Interval analysis
• Fuzzy arithmetic
• References
• Acknowledgments
• Software requirements

        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. Uncertainty comes in at least two kinds: ignorance (just us not knowing what the value is even though it may be knowable) and variability (fundamental heterogeneity of values with associated frequencies). In the latter case the value is unknown able, but the probability distribution is.

        RAMAS Risk Calc is a comprehensive tool, which allows you to do all kinds of computations carrying both types of uncertainties along in a natural way. Inputs can be precise and uncertain numbers characterized by both ignorance and variability. You do not have to stand on your ears trying to invent a probability distribution based on 3 data points: with insufficient data; just treat it as ignorance. You can account for both probabilistic information and ignorance correctly if you have RAMAS Risk Calc.

        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. RAMAS Risk Calc 3.0 used both traditional methods such as probability theory and interval analysis and the newest techniques such as probability bounds analysis and fuzzy arithmetic to represent 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.

RAMAS Cast
Disease Cluster Analysis (version 2.0)

        RAMAS CAST is a program for the display and statistical characterization of desease clusters. 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. However, humans are likely to perceive clusters even in purely randomly distributed data. The statistical problem is to determine whether there exists an excess of desease incidence - a cluster - above - what might be expected by chance alone. Clustering may exist in time, or in space, or in both space and time. CAST blends three-dimensional graphical displays and state-of-the-art statistical methods to fully describe a suspected cluster in space or time. Supported test include Knox, Mantel, Ederer-Meyer-Mantel, nearest neighbor, and a variety of other methods.

Requirements: IBM PC, XT, AT or PC/2, 640 KB RAM, hard drive, math coprocessor (optional); EGA or VGA monitor; DOS 2.0 or higher.

Cost: See Software Price List and Ordering Information.