Maple bugs: Thomas Richard: Hurrah, Maple quality improves! - Example 3

From: Vladimir Bondarenko (vb_at_cybertester.com)
Date: 03/04/05 

Date: 4 Mar 2005 02:12:01 -0800

Hi Maple customers all over the world,

The other day Herr Richard, Maple Support, Scientific Computers
GmbH, made an attempt to persuade us that Maple quality does not
deteriorate over the versions:

http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/83505ab90dd16760

Here is yet another example selected of thousands. If you are
a freshman or a sophomore, or a math student of any course, I
believe you will be in perfect delight seeing the following
Calculus I level pearl.

What Maplesoft promise you ("We work work work to help you as
much as possible").

http://www.maplesoft.com/

Maplesoft> "Maplesoft technologies are ideal for students
Maplesoft> enrolled in any math, science or engineering
Maplesoft> course. Learn how you can use Maple to save
Maplesoft> time, learn more and improve your grades."

As you understand, the factorial of a negative number does not
exist, say draw this

> plot(z!, z=-5..5,-10..10);

or try this

> (-1)!;
Error, numeric exception: division by zero

Now try this which is also correct.

> sum(1/n!, n= -1..1);
Error, (in NumericRange) summand is singular in the interval of
summation

Now rejoice by the improved Maple quality (just an example of
thousands distinct ones)!

Observe that Maple quality comes so to say, in waves. This is
one of several typical ways of Maple quality deterioration we
demonstrate in our Review of Maple coming.

................................................................

????-1994 - Maple cannot calculate the sum.

1995-2000 - The answer does not exist, but Maple returns exp(1).

2001-2003 - All works correctly.

2004-2005 - The answer does not exist, but Maple returns exp(1).

................................................................

sum(1/n!, n= -1..infinity);

-------------------- (2004) Maple 9.5.2 -----------------------

exp(1)

-------------------- (2004) Maple 9.5 -------------------------

exp(1)

-------------------- (2003) Maple 9 ---------------------------

Error, (in sum/infinite) summand is singular at n = -1 in the
interval of summation

-------------------- (2002) Maple 8 ---------------------------

Error, (in sum/infinite) Summand is singular at n = -1 in the
interval of summation

-------------------- (2001) Maple 7 ---------------------------

Error, (in sum/infinite) Summand is singular at n = -1 in the
interval of summation

-------------------- (2000) Maple 6 ---------------------------

exp(1)

-------------------- (1997) Maple V Rel 5 ---------------------

exp(1)

-------------------- (1995) Maple V Rel 4 ---------------------

exp(1)

-------------------- (1994) Maple V Rel 3 ---------------------

sum(1/n!,n = -1 .. infinity)

----------------------------------------------------------------

The same bug manifestation with

sum(1/n!^2, n= -1..infinity);
sum(1/n!^3, n= -1..infinity);
sum(1/n!^4, n= -1..infinity);
sum(1/n!^5, n= -1..infinity);

sum(1/n!, n= -infinity..infinity);
sum(1/n!^2, n= -infinity..infinity);
sum(1/n!^3, n= -infinity..infinity);
sum(1/n!^4, n= -infinity..infinity);
sum(1/n!^5, n= -infinity..infinity);

that is the answer does not exist but Maple 9.5.2 returns
cheerfully stuff like BesselI(0,2), hypergeom([],[1, 1],1),
hypergeom([],[1, 1, 1],1), hypergeom([],[1, 1, 1, 1],1) or
infinity.

More about Maple quality degradation can be found at

Maple bugs: asympt quality degradation sample
http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/260c254f34c9bb50

Maple bugs: evalf quality degradation sample
http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/858e0c219f9a8e07

Maple bugs: rsolve quality degradation sample
http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/da8354b79b156d5f

Maple bugs: minimize(z^4-2*z^2+z, z= 0..1);
http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/2b05838db6cbdc65

Maple bugs: A dangerous, misleading ad statement at the main
Maplesoft's site
http://groups-beta.google.com/group/comp.soft-sys.math.maple/msg/8738365a6702a63e

Enjoy improved Maple quality promised us the Maple customers,

Vladimir Bondarenko
VM and GEMM architect
Co-founder, CEO, Mathematical Director
Cyber Tester, LLC

http://www.cybertester.com/
http://maple.bug-list.org/
http://www.CAS-testing.org/

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