I've beening puzzled with the function definition of the "plotxd" interface of maxima.
for example :
plot2d (
[
sin(x),
[discrete, vx, vy],
[parametric, 10 + 3 * sin(2*t), 2 + 2 * cos(3*t), [t, 0, 2*%pi]]
],
[x, 0, 15],
);
It's correct, but the definition of the continuous function "sin(x)" is not consistent with the that of the "discrete" data sets as well as the "parametric" function. Why not the above code be writen as the following form:
plot2d (
[
[sin(x), [x, 0, 15]],
[discrete, vx, vy],
[parametric, 10 + 3 * sin(2*t), 2 + 2 * cos(3*t), [t, 0, 2*%pi]]
]
);
this form is clean and all the definition of function is consistent.