Hi, that's true... I have been playing with maxima.
I define the function F(x,y,z):=38244.74787*%pi*(x^2+y^2+z^2)^0.125 +1615.975261*%pi*z^2/(x^2+y^2+z^2)^0.875 +(-1292.78021)*%pi*z^2/((x^2+y^2+z^2)^0.875*(1+y^2/x^2)) +1292.78021*%pi*(x^2+y^2+z^2)^0.125/(1+y^2/x^2); then I factor it factor(F(x,y,z)=0); Multiply it by the denominator % * 32365900000*(z^2+y^2+x^2)^(7/8); divide by pi % / %pi; So that F(x,y,z)=0 is equivalent to 1290128178785633*z^2+1237825685085633*y^2+1279667680084472*x^2=0 The only real solution is 0,0,0, But then I try to define a cube centered at the origin which contains at least a part of the surface: load(draw); n: 10$ draw3d( enhanced3d = true, implicit( F(x,y,z) = k, x,-n,n,y,-n,n,z,-n,n)); Since it's taking huge values even for small x,y,z, one has to use either very small n or very large k but even in that case I get draw3d (implicit): non real value How could I check the same in matplotlib? Am I missing something? Maybe this is a bug in maxima... Any help will be appreciated! On Tue, Jan 22, 2013 at 3:29 PM, Benjamin Root <ben.r...@ou.edu> wrote: > > > On Mon, Jan 21, 2013 at 8:06 PM, Pau <vim.u...@googlemail.com> wrote: >> >> Hi, >> >> I am somehow new to matplotlib and I am trying to plot this function of x >> ,y ,z >> >> F(x,y,z)= >> 38244.74787*Pi*(x^2+y^2+z^2)^.125+1615.975261*Pi*z^2/(x^2+y^2+z^2)^.875-1292.780210*Pi*z^2/((x^2+y^2+z^2)^.875*(1+y^2/x^2))+1292.78*Pi*(x^2+y^2+z^2)^.125/(1+y^2/x^2) >> >> in a similar way as >> >> http://matplotlib.org/mpl_examples/mplot3d/contour3d_demo3.hires.png >> >> The code is >> http://matplotlib.org/mpl_examples/mplot3d/contour3d_demo3.py >> >> But I have no idea where to start... >> >> some help would be appreciated... >> >> thanks >> > > The reason you are having difficulty coming up with a way to plot this is > because you have 3 input dimensions, and 1 output dimension that you wish to > plot. If you were to plot this in 3D space, it would have to be done as > F(x,y,z) as a colored "mist" in the domain of (x,y,z). While a "mist" can't > be done in mplot3d, you could plot out scatter points to emulate this. One > could also use contourf3d(..., zdir='z', offset=...) to create slices of the > filled contours, similar to this example: > > http://matplotlib.org/examples/mplot3d/contourf3d_demo2.html > > Now, if the domain of (x,y,z) can be parameterized as a surface (i.e., a > sphere or a cylinder), then you are looking to do an image of F(x,y,z) > plotted on that surface, which is a little bit difficult, but also do-able > using the plot_surface() function. > > Cheers! > Ben Root > ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_jan _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users