C Floating point arithmetic

carl carl at bdaemon.UUCP
Sat Nov 30 04:15:54 AEST 1985


.......
> >analyst should make the determination.  I have seen enough
> >computations that produced total garbage to make me believe
> >that the naive user should get double precision by default.
> >
> 
> This argument is hard to swallow. You are suggesting protection
> for the user by not giving him what he has asked for in his
> code.  Any intelligent scientific programmer trys it both ways
> on his own and determines whether single precision is adequate
> (without the help of a numerical analyst, an analyst is consulted
> when one wants to understand the root of the problem in an attempt
> to rearrange the computation so that single precision is sufficient
> should it fail).  .... more stuff, largely irrelevant .....

I hope never to have the misfortune to have to use one of your programs.
The notion that "trying it both" ways guarantees a program that will never
blow up is patently absurd and in fact accounts for many of the horror
stories that give the use of computers a bad name.  Consulting a numerical
analyst *before* developing a program serves the same purpose as consulting
a statistician well versed in experimental design before starting data
collection -- the chances of wasting the client's money and time are
greatly reduced.



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