nacer@mist.cs.orst.edu (Abdenacer Moussaoui C.) (01/20/88)
From what I have tried there is no support for sin() cos() functions.
May be clipper supports them however I don't want to loose the interpretive
mode of db3+ at least at this stage.
(1) I think db3+ supports some sort of object code LOADing and CALLing
has anybody
implementated such "basic" trig stuff in whatever (asm,c,...) ???
(2) Is there such thing as user-defined function in db3+?
(3) How to go about seting up some mem-vars to simulate predefined constants
such as PI for example?
(4) Ideally I would like to have these suppositely constants in database
where they could be easily modified and then set again.
I tried a simple 2 field database with name and value fields
then I used:
USE CONST.DBF
DO WHILE .NOT. EOF()
STORE VALUE TO &NAME && store value in the variable contained
&& in the field NAME
SKIP
ENDFO
this would have been great if it worked. I think for such thing to
work implies that mem-vars need to be allocated on the heap and not in
the *fixed* data-segment.
Thank you.
--nacertr@wind.bellcore.com (tom reingold) (01/30/88)
At my last job, I programmed in dBase III extensively and I think I still remember it. (I left in spring '87). I had to use so many tricks to compensate for the bad design of dBase III. I had at least two solutions to problems similar to yours. One is to buy dBase Tools for C. This is 1) a library of routines that are loaded into memory and callable from dBase. The calling sequence and the setup procedure is so bad, I would not recommend this package. It is also 2) a way by which you can write functions to add to the ones that are loaded in memory. I never got around to trying it because it had the disadvantages of (1) and a screwy way of writing the additional routines. I hope Ashton Tate programmers someday get shot for their designs. Another solution seems more kludgy but works better. Get your data into a small temporary database. I assume you can do this. Then use the "copy to <file1> delimited with blank" command. This will create a text file that a C program can read. Then from within your dBase program, run the C program with "run myprog". The C program will read in the text file, do the calculations, then write out a new text file. Then in your dbase program, use a new and empty database and grab the data using the "append from <file2> delimited with blank" command. Then move this data back into your main database. One bug in this second solution is that the computer tended to hang if I did many "run" commands and I had to start over. I think "many" means about 75. The "copy" command can operate on a range so that the data you are sending to the first file may not have to be in a temporary database. You may be able to use "copy rest to <file1> delimited with blank" or something like that. Any more questions? Tom Reingold INTERNET: tr@bellcore.bellcore.com Bell Communications Research UUCP: rutgers!bellcore!tr 435 South St room 2L350 SOUNDNET: (201) 829-4622 [work] Morristown, NJ 07960 (201) 287-2345 [home]