hi Judah
> well, they're related because they're both basic, probably FAQ's. Is
> there a FAQ, by the way?
2. is not FAQ level.
> 1. why does the "vect" package redefine "." as commutative? Makes it
> hard to do matrix multiplication.
>
now we need not redefine "." as commuative.
so,vect.mc
line 29
you shoud rewrite
DECLARE([".",ORDER],COMMUTATIVE,
ORDERN,NARY,
["GRAD","DIV","CURL","LAPLACIAN"],OUTATIVE,
"CURL",NONSCALAR)$
to
DECLARE([ORDER],COMMUTATIVE,
ORDERN,NARY,
["GRAD","DIV","CURL","LAPLACIAN"],OUTATIVE,
"CURL",NONSCALAR)$
then
(C1) load(vect);
(C2) v1:[a,b,c]$
(C3) v2:[d,e,f]$
(C4) mv1: matrix(v1)$
(C5) mv2:transpose( matrix(v2))$
(C6) express1(v1~v2);
(D6) [b f -c e,c d - a f, a e - b d]
(C7) mv1.mv2;
(D7) c f + b e + a d
(C8) mv2.mv1;
[ a d b d c d ]
[ ]
(D8) [ a e b e c e ]
[ ]
[ a f b f c f ]
(C9) v1.v2 - v2.v1;
(D9) 0
that's compatible with matrix multiplication.
> 2. I want to use (e.g.) "beta" as a function name, but it's already a
> special function ... how can I clear or undefine that?
>
Like on C++,we shoud be able to control name space with context mechanism on MAXIMA.
But that is too complex to use for beginner.
For example,(C10) functions;
(D10) [EV_DIFF(X),.........,TRIGSIMP(EXPN),......]
(C11) fundef(trigsimp);
TRIGSIMP1(NUM(EXPN))
(D11) TRIGSIMP(EXPN) := RATSIMP(----------------------)
TRIGSIMP1(DENOM(EXPN))
we know at this point,global MACSYMA function TRIGSIMP is redefined.
(C12) load(trgsmp);
(C13) fundef(trigsimp);
(D13) TRIGSIMP(X) := TRIGSIMP3(RADCAN(APPLY1(X, TRIGRULE1, TRIGRULE2,
TRIGRULE3, TRIGRULE4, HTRIGRULE1, HTRIGRULE2, HTRIGRULE3, HTRIGRULE4)))
maybe this definition is original.
overwrite is dangerous until you grow accustom to use maxima.
i think ...
gosei furuya (go_furuya@infoseek.jp)
> thanks!
>
> Judah
>
> ----
> Judah Milgram (301) 227-1536 (voice)
> Carderock Division, NSWC, Code 5301 (301) 227-2584 (fax)
> 9500 MacArthur Blvd. milgramjh@nswccd.navy.mil
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