7.116 bug in parallelepiped, Maple 7 (13.12.01)

7.116.1 Harry Kneppers

In Maple 7, the geom3d[parallelepiped] command doesn’t do what I want and I don’t know what mistake I am making.

If I do

with(geom3d): 
point(A,1/2,0,0), point(B,1,0,0), point(C,1/2,2,0), point(D,1/2,0,3): 
dsegment(d1,[A,B]), dsegment(d2,[A,C]), dsegment(d3,[A,D]): 
parallelepiped(pp,[d1,d2,d3]); 
draw(pp);
 

it doesn’t look like a parallelepiped. I get this kind of trouble as soon as A is not the origin.

I also tried to start with a parallelepiped at the origin and then use geom3d[translation], but that did not help me out. It gives a nice picture, but it is not what I want.

7.116.2 Robert Israel (15.12.01)

There’s a simple mathematical bug in "parallelepiped". The expressions \(B+C-2*A, E+C-2*A, B+C+E-3*A\) and \(B+E-2*A\) in lines 25 to 28 should be \(B+C-A, E+C-A, B+C+E-2*A\) and \(B+E-A\) respectively.

It is corrected with Maple 8 (U. Klein)