|The essence of RPN vs AOS/EOS|
Message #50 Posted by Karl Schneider on 10 Aug 2006, 11:39 p.m.,
in response to message #48 by Palmer O. Hanson, Jr.
Palmer Hanson posted:
The "... you just copy the formula ..." words capture the position of the AOS community and the old "... do the arithmetic just like you would with pencil and paper ... " words capture the position of the RPN community.
Yes, that is the distilled essence of the difference between RPN and AOS/EOS.
RPN embodies the approach one would actually take when solving a problem on paper, using only simple computing aids, such as trigonometric and logarithm tables and a slide rule -- perform computations individually, where the input arguments are already available for use.
AOS/EOS embodies the rote "Solve the problem by keystroking exactly what you see on the paper" approach.
Of course, I prefer RPN, because one is generally performing a given calculation only once. A tested and debugged equation for solving the particular problem will probably not be available; consequently, seeing each intermediate result and knowing what it represents is very important for having confidence in the final result.
In EOS (e.g., Casio fx-115MS, TI-80 series) the expression that shows in the display seldom matches visually what is written or printed on the paper, for a variety of reasons. Unfortunately, that is the only means of verifying the correctness of a complete expression prior to hitting "=" or "ENTER" to produce a result that must be accepted on faith.
In AOS, one sees intermediate results irregularly (only as dictated by heirarchy), and it's sometimes difficult to determine what operation(s) were consummated. The user may need to insert parentheses in places where none are present on the paper.
RPN will never become obsolete!