Hello,
I have two questions:
1. what option should I add to the plotting command below (either in plot3d or in draw3d) to tune the z-range to [0,10] for instance ?
Maxima commands:
f(x,y):=9-x^2-y^2; plot3d(f(x,y),[x,-3,3],[y,-3,3]);
or
load(draw);
f(x,y):=9-x^2-y^2; draw3d(explicit(f(x,y),x,-3,3,y,-3,3));
2. again, I guess there is an option I did not find out to get a scale ratio of one for plotting contours. What should I write ?
Maxima commands:
f(x,y):=9-x^2-y^2; contour_plot(f(x,y),[x,-3,3],[y,-3,3]);
/* contour_plot gives a region [-3,4]x[-3,4] by the way, which is not nice */
or
load(draw);
f(x,y):=9-x^2-y^2; draw3d(explicit(f(x,y),x,-3,3,y,-3,3),contour=map,contour_levels=10);
Thanks a lot in advance to anyone who can help,
Pascale Voirin,
teacher in mathematics.