## bug in type

Maple

Bug in type(HFloat(-infinity),  pos_infinity). Negative infinity is incorrectly recognized as positive one:

s:=HFloat(-infinity);
HFloat(-infinity)

type(s, neg_infinity);
type(s, pos_infinity); # bug
...

## BUG in numerical integration? with SphericalY's...

Hi,

I'm computing some difficult integrals, involving Spherical Harmonics. I've proved that the answer must be a real number, and yet Maple returns a complex number. Also Mathematica returns purely real numbers, so I wonder if there is a bug in Maple. I found if I break the integrand into real and imaginary parts, and add them I get the right answer...usually.  Anyway's here's the code and the proof, I suspect they could be a bug...

## Plotting Spherical Harmonics ERROR...

Hi,

Theres seems to be an error in the SphericalY function when the input is SphericalY( l, -l, theta, phi)

restart;

assume(phi, real):assume(theta, real):

for l from 1 to 2 do
m:=-l;
s:=SphericalY(l,m,theta, phi);
f:=s*conjugate(s);
plot3d(f, phi=0..2*Pi,theta=0..Pi,coords=spherical);#sphereplot(f, phi = 0 .. 2*Pi, theta = 0 ..Pi,  style...

## Strange bug in Maple 16...

The second graph is incorrect. The reason?

plots[polarplot]([3+cos(4*t), 2-cos(4*t)], t = 0 .. 2*Pi)

## A fast bug fix and Maple Mathematica bug fix compa...

The latest quick update fix for a bug is the fastest fix I have seen in a long time.  A nice surprise actually.

In my travels I happened to come across this ... "Since then, we’ve successfully released a new build of Wolfram|Alpha’s codebase each week, incorporating not only hundreds of minor behind-the-scenes enhancements and bug fixes, but also a steady stream of major new features and datasets."  taken from here

## [16.0] Strange bug at startup...

I have a very strange bug with Maple 16. When I try to start it, Maple loads its shell and starts to consume 100% CPU (maple.exe, not mserver.exe). If I try to calculate something, it throws something like "waiting for server connection". In 3 to 10 minutes Maple suddenly stops doing this and then works normally until I reboot Windows. What's this? Maple 16.0, Windows XP SP3.

PS. I do not have such bugs on my home PC with Windows XP SP2.

## Strange behaviour of series expansion, is this a b...

Hi,

is the series expansion for the following expression bugged in maple or am I missing some crucial thing of series?

series((1/epsilon-log(4)),epsilon=0);

results in epsilon^-1 -2 -2*ln(2)

for xmaple 16.01. The console version does not add the wrong term "-2".

Apparently it works here:

## save, tables and names...

Hello,

I just lost the result of a 20h calculation due to the last-name evaluation using tables. Consider that

`t := table([1=2]):`
`s := t:`
`save s, "table":`
`restart:`
`read "table":`
`s[1];`

evaluates to t[1]. The save command only...

## Bug report: codegen[optimize] generates an unknown...

by: Maple 16

The version 16 of Maple does not know the function "pow", it is replaced by "power". Nevertheless, the codegen[optimize] procedure still generates it!  Moreower, it's not optimal even to write poser(..., 1/2)  as, most probably, the function sqrt must run faster.

Here's an example: (the function being optimized just contains some nested square roots)

`> iang10 := [codegen[optimize](Re(int11), tryhard)];[       2        t17                                   `

## A problem with using "subs" command...

While substituting expressions for θ(t),θ'(t),θ''(t) with some rather simple polynoms (see attached demonstration), the result icludes terms such as "·2" or "θ1·" (see terms multiplying ε8 and ε7in result for C1). It seems MAPLE treates the "·" sign as a variable/constant instead of as an operator. What am I doing wrong?

## Win7 and Compiler...

`I installed M16 32 Bit on my new machine with Win7 64 Bit.But the following results in crushing mserver.exe:  tmp := proc( x :: float ) :: float; 2.3 * x end proc:  cp:=Compiler:-Compile(tmp);with system info below. Do I have to set certain rights for the compiler or define a specific working directory?The FAQ http://www.maplesoft.com/support/faqs/results.aspx?search=compiler does not help me.Dito http://www.maplesoft...`

## Minor plot issue...

The plot is fine until specifying the upper limit too high at which point the lower limit on the x axis is ignored from view. Works on Maple 12, does not in Maple 16.

I have trouble with Maple's add-function. It is usually very good at manipulating my sums using Binomial coefficients, but Maple calculates outright wrong in this example, when using the sum-function:

http://dl.dropbox.com/u/22027008/maplePlay.mw

I would like to use Maple's features for reasoning about expressions (solve etc.), so the numerical add is not desirable. What to do?

## Bug in implicitplot command

Maple

It is the first time  I post a Maple bug in MaplePrimes because I use to submit an SCR.
There is a serious reason to do so. Let us look at the output of
> with(plots):
> implicitplot(sqrt(x^2+y^2)-sqrt((x-4)^2+(y-3)^2) = 5, x = -20 .. 20, y = -20 .. 20,
numpoints = 10^6, thickness = 5, scaling = constrained);
(both in Maple 13 and in Maple 16)

## Trouble with arrows=line option in DEplot

by: Maple 16

There is a flaw (bug) in the DEplot routine.  If you load the plottools package before using DEplot with the arrows=line option, the DEplot routine tries to use the line definition from the plottools package.  A worksheet illustrating this problem is below.

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