2009/10/18 Tom Verhoeff <t.verho...@tue.nl>: > A simple example is the situation where one needs to calculate > the replacement resistor value R for parallel resistors having > values R1, R2, ..., Rk. The formula is R = 1/(1/R1 + 1/R2 + ... + 1/Rk). > The formula gives a divide-by-zero if one of the resistors has value 0. > But in that case, the replacement value R also equals 0. When allowing > infinities, it just works out fine (infinity + x = infinity, 1/infty = 0). > That is precisely why IEEE 754 has infinities. Also see > > <http://www.cs.berkeley.edu/~wkahan/ieee754status/why-ieee.pdf> > > for other examples and further motivation.
Mmm... the formula R = 1/(1/R1 + 1/R2 + ... + 1/Rk) is only valid if none of Rn=0. Programmers can and must take care of that situation. Gustavo _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
