Re: A86: cool graphing stuff?
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Re: A86: cool graphing stuff?
David Phillips wrote:
> >first, to do plus or minus do {-1,1}(eqn) where 'eqn' is the equation (i
> >think this is used in various programs so nothing new...)
> Learned that back on the 82. You can use a big immediate list and graph
> complicated graphs in one equation:
> y1={1,2,3,4,5,6,7,8}sin x
You can put them anywhere you want in the equation, too. you can do +/- and
-/+. i once had to graph abs(abs(abs(x)-1)-2)=abs(abs(abs(y)-1)-2)... (on
the '97 AIME, although i didn't have a calc when i had to do it and it's more
fun w/out it anyway, but i checked it after the test on my 85...) and i had
like y={-1,-1,-1,-1,1,1,1,1}......... etc...Also, I onced used that on my 85
to make a 3d graphing program :-) I was thinking about making it asm because
of how slow it is.. maybe this summer i might tackle making new graph types
(in addition to func, pol, par, difeq) like conic, seq, and 3d... i wonder
what it would entail to allow tracing, etc... if i can't get that, i'll at
least make a prog that will graph each type. does anyone have a call that
will maybe take an equation (either at (hl) or maybe with var name in OP1 or
something) and will evaluate it with the current variables? that would be
relly helpful and if no one has one i'll have to look for it when i get some
free time.. :-)
> >secondly, to do a piecewise function you do the condition multiplied by
> >the equation for that piece plus all the others. an example will help:
> >
> >f(x)=x {x<0}
> >f(x)=x^2 {x>=0}
> >
> >to graph you would enter the following as 'y1':
> >(x<0)(x)+(x>=0)(x^2)
>
> Wow, I never thought of that. Does anyone one else have fun impressing
> their entire math class (including the teacher) with all your "useless"
> calculator knowledge?
You can do something similar if you just want to restrict the domain. you
can divide it, so if you want "x^2-x+1" over [1,5] you can put
y1=(x^2-x+1)/((x>=1)(x<=5)). That will make the numbers outside the domain
be undefined... But this doesn't work for piecewise functions... :-(
--
Stephen Hicks
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