georg@exunido.uucp (Georg A. M. Heeg) (01/07/89)
In article <451@ubbpc.UUCP> wgh@ubbpc.UUCP (William G. Hutchison) writes: > This is interesting, but not exactly the _type_ of answer I was looking for. >It seems to me that you may be using dynamic classes because they are _there_, >not because you really need them. Could your applications be written using >statically declared classes? Are dynamic classes necessary for application >development in a structured "software engineering" sort of way, or just handy >for improvising programs at the terminal? > It is not necessary (you can simulate a turing machine in c and thus in c++ :-)) but really handy: William mentions "development". You can really develop interactively a program try notions (classes) try hierarchies and redesign them. To my opinion software development is a creative process with a lot of design and redesign cycles and improvising is often a valuable first step to get a rough idea of a new application field. ...... > Is this literally true? What about checking values for "close to zero" >in pivoting? Complex numbers are not well-ordered, so you probably want to >check if the magnitude of the number is close to zero. Close to 0 means: | a(i,j) | < epsilon (in mathematical notaion) In Smalltalk-80-Notation (a at: i@j) abs < epsilon Certainly abs is differently defined for real and complex numbers. > Thanks for the info. Does anybody know if one of the inexpensive Smalltalk >implementations runs correctly on the AT&T 6300PLUS (80286) ??? Smalltalk-80 is a large memory system and you can hardly address 4 or 8 MB with 16 bit addresses of a 80286 linearly. You need a 80386 to run it. It is available since december 88 from ParcPlace Systems, Palo Alto, e-mail: sales@ParcPlace.com or from us (for Germany, BeNeLux, Austria and Switzerland) and this version runs under MS-DOS. May be somebody recommends to you Smalltalk-V, I don't. Georg Heeg Smalltalk-80 Systeme Baroper Str. 337 D-4600 Dortmund 50