5.2 3d calculation from v5 takes 60times more on v7 (15.10.01)

5.2.1 Martyn Caron (23.10.01)

We had buy a v7 version of Maple. All my calculation that was working good on v5 take up to 60 times more on v7. My PC is an PIII/866, on Windows 98 SE. Ex. Takes 3 second on v5 takes 180 seconds on v7. Here is an exemple of the calculation:

restart;with(plots):with(plottools):
De forme avec des cylindres;
volume:=cuboid([0,0,0],[4,4,4],color=green):
f1:=cylinder([2,2,3.9],0.5,0.15,color=pink):
f3:=seq(rotate(cylinder([3.9,i,i],0.4,0.15,color=pink),Pi/2,[[3.9,0,i],
[3.9,4,i]]),i=1..3):
f6:=seq(seq(cylinder([i,j,-0.05],0.4,0.15,color=pink),i=1..3),j=[1,3]):
display(volume,f1,f3,f6,scaling=constrained,axes=none,orientation=[-40,70]);
c1:=cylinder([0,0,0],1,1,color=red):
rotate(c1,Pi/2,[[1,1,1],[2,2,2]]);



5.2.2 Frank Gerdes (15.10.01)

Because I am thinking about upgrading from Maple 6 to Maple 7, I did the test with Martyn’s code.

My system is a PC with WIN 98 SE, 366MHz, 128MB.

Maple V Release 5.1: 85 seconds

Maple 6.02: 193 seconds

The perfomance diﬀerence is not as dramatic as the one reported by Martyn, but certainly signiﬁcant.

I made sure to quit Maple V version before I started Maple 6 and vise versa. I also repeated the test after rebooting, etc.

Now, I am wondering whether Martyn’s result with Maple 7 tell me that I should stay away from Maple 7.

5.2.3 Robert Israel (16.10.01)

Examination of the code of plottools[rotate] shows an obvious ineﬃciency: the transformation involves a function that is hellishly complicated, but should be very simple. One possible patch is to make a1, a2, a3 local variables and change line 41:

f := proc (a1, a2, a3) ...etc... end proc



to

f:= unapply(...etc..., a1,a2,a3)



5.2.4 Thomas Richard (26.10.01)

Frank Gerdes wrote:

| I made sure to quit Maple V version before I started Maple 6 ...

This should be unnecessary for such comparisons (except in cases with extreme memory consumption).

| Now, I am wondering whether Martyn's result with Maple 7 tell me ...

Wrapping the last rotate statement in display() (probably intended so), I obtain these timings (P-III 700MHz, NT4 SP6, Matrox G200 AGP):

Maple 7 : 53.326s

Maple 6.02a: 51.363s

Release 5.1: 32.305s



In Release 5.1, the graphics are not as accurate as in newer versions: the dice marks are not completely ﬁlled, and the grid lines are less regularly distributed on the cylinder. Maybe a matter of taste...

5.2.5 Frank Gerdes (25.10.01)

Meanwhile I got Maple 7 and found that it is as slow as Maple 6 when executing Martyn’s code. I mean slow compared to Maple V R5.1 (see previous postings below).

I had a look at the code of plottools[rotate] and I agree that is is very complicated and that it might be ineﬃcient. But I am fairly sure that Maple V R5.1, Maple 6 and Maple 7 use the same code. I did a visual inspection and could not ﬁnd any signﬁcant diﬀerences.

So, that leaves me still puzzled why Maple 6 and Maple 7 are so much slower when executing plottools/rotate'-code than Maple V R5.1.

P.S.: I suppose most of the time one doesn’t notice these things, because PCs seem to get faster at a slightly larger rate than software gets slower.

I got the following timings: (U. Klein)

MapleV.5.1: 42.899s

Maple6.01: 77.361s

Maple7: 85.040s

Maple8: 4.210s