[Maxima] ev, subst, funmake, quote, apply ... argh!
dlakelan at street-artists.org
Wed Dec 26 16:35:39 CST 2007
Robert Dodier wrote:
> On 12/25/07, dlakelan <dlakelan at street-artists.org> wrote:
> ev(expr, nouns) verbifies all nouns in expr. ev(expr, foo) verbifies
> only foo.
>> In other words, what's the "right" way?
> Well, there are two general approaches, to treat the figure of merit as
> an expression or as a function. You could give a function name or
> lambda expression as the f.o.m. argument, and then call apply to
> evaluate it for some specific arguments. Or you could construct an
> expression (maybe a noun expression as shown above) and then
> evaluate it in an environment with some variables bound to specific
I understand now that 'err(a,b,c,d) is not the same as '(err(a,b,c,d))
which was what was confusing me. What exactly do I get when I type
"'err(a,b,c)" ?? I don't know.
I think this area of maxima is ripe for confusion for users and perhaps
we can devote some text to it in the manual??? It has bitten me for
plot2d, find_root, and now my own minimizer.
So now my interface for my minimizer takes an expression, and evaluates
it using "ev" rather than subst. I find ev in this specific context to
make more sense. If someone cares to enlighten me on whether there is a
better alternative to the use of "ev" within the minimizer code I'd be
happy to hear it.
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