Hi Dmitry,
this is even simpler, and will give you a better plot:
plot3d(sin(r^2*sin(2*theta)/2),[r,0,1],[theta,0,2*%pi],[transform_xy,
polar_to_xy])$
See the documentation and examples in
http://maxima.sourceforge.net/docs/manual/en/maxima_12.html
Regards,
Jaime
On 11/16/2012 08:04 PM, Dmitry Shkirmanov wrote:
> Thanks. I slightly modified your approach:
>
> f(x,y):=if x^2+y^2>1 then false else sin(x*y)$
> plot3d(f(x,y),[x,-1,1],[y,-1,1])$
>
> It returns very good graph.
>
> Actually, in real task, i have more complicated condition then
> -sqrt(1-x^2)<y<sqrt(1-x^2) (something like h(x)<y<g(x), where h(x),
> g(x) some functions) , so i cannot use parametric_surface.
>
> Just a curiosity: why
>
> f(x,y):=block([],
> if (y< -sqrt(1-x^2)) then return(0),
> if (y>sqrt(1-x^2)) then return(0),
> return(sin(x*y)));
>
> is not working?
>> Try this:
>>
>> f(x,y):=if x^2+y^2>1 then 0 else sin(x*y)$
>> plot3d(f(x,y),[x,-1,1],[y,-1,1])$
>>
>> or also this:
>>
>> load(draw)$
>> draw3d(parametric_surface(r*cos(theta),r*sin(theta),sin(r^2*sin(2*theta)/2),r,0,1,theta,0,2*%pi))$
>>
>>
>> See the documentation for the draw package. And also this document:
>> http://www.austromath.at/daten/maxima/zusatz/Graphics_with_Maxima.pdf
>>
>>
>> Le 16/11/2012 19:02, Dmitry Shkirmanov a ?crit :
>>> i tried this:
>>>
>>> f(x,y):=block([],
>>> if (y< -sqrt(1-x^2)) then return(0),
>>> if (y>sqrt(1-x^2)) then return(0),
>>> return(sin(x*y)));
>>>
>>> plot3d(
>>> f(x,y),[x,-1,1], [y, -1,1]
>>> );
>>>
>>> But this does no work. I got graph of function sin(x*y). What is
>>> wrong?
>>>> Hello, list.
>>>>
>>>> By using maple it's possible to plot something like this:
>>>>
>>>> plot3d(sin(x*y), x = -1 .. 1, y = -sqrt(1-x^2) .. sqrt(1-x^2), axes
>>>> = boxed);
>>>>
>>>> Here the area that coordinates x,y are changing in is a circle
>>>> instead of square.
>>>>
>>>> I tried to do the same with maxima:
>>>> plot3d(sin(x*y),[x,-1,1],[y,-sqrt(1-x^2),sqrt(1-x^2)]);
>>>> But maxima says: plotting: range must be of the form [variable,
>>>> min, max]; found: [y,-sqrt(1-x^2),sqrt(1-x^2)].
>>>>
>>>> So, is there any way to plot by maxima a function f(x,y) that is
>>>> bounded by other functions in the x-y plane?
>>>> .
>>>
>>> _______________________________________________
>>> Maxima mailing list
>>> Maxima at math.utexas.edu
>>> http://www.math.utexas.edu/mailman/listinfo/maxima
>>>
>>
>> _______________________________________________
>> Maxima mailing list
>> Maxima at math.utexas.edu
>> http://www.math.utexas.edu/mailman/listinfo/maxima
>>
>>
>
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima