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with pointplot3d and 14,000 points when I enter symbol=point I get an empty plot.

Only when I set symbolsize=1 (a point) do I get points appearing in the graph.  Bug?

Hi there

There seems to be a bug when evaluating elliptic integrals using assuming. Here's an example:

 

INT:=Int(1/sqrt(a*x^3+1),x=0..X);

is our integral for some a. Now evaluate the integral using assuming on X in different ways:

 

INT2:=simplify(value(INT)) assuming X>0, a>0, a<1;

INT3:=simplify(value(INT)) assuming X<0, a>0, a<1;

 

These give analytic solutions which are different. Now plot them both and compare to the numeric solution

 

plot([subs(a=0.1,INT2),subs(a=0.1,INT3),subs(a=0.1,INT)],X=-1..1,colour=[red,green,blue]);

 

I'm finding that the red curve which should work for X>0 is wrong, while the green one which is for X<0 is ok for X either sign. [blue is the correct answer - numerically!]

 

Any ideas?


firstly apologies in advance for stuff in this question such as "triangle symbol",  my computer is pretty old. 


ok so i was confused a bit here, what i'm trying to do is write a maple procedure that computes Af for a given f contained in V . except we only need to correct the bug in the script below. This script demonstrates such a procedure in the case that omega is a square. The domain is given here as the negative set of a function F contained in V .  I have left in notes where/what i think we need to do but i dunno how to...

N:=10 ; # Global Var
F:=(x,y)->sgn(abs(x-N/2)+abs(y-N/2)-N/4);
Average := proc(F, f0) local f, i, j;
f := f0; # !!!!!!!!!!!!!! something is bad here...
for i to N do for j to N do
if F(i, j) < 0 then
f[i, j] := (f0[i - 1, j] + f0[i + 1, j] + f0[i, j + 1] + f0[i, j - 1])/4 ;
end if;
end do;end do;
return f;
end proc;
f0:=Matrix(N,F); # just to have something to test the procedure
Average(F,f0); # does not return the expected average, modifies f0

 

the necessary information we were given to produce this so far was..

Let N be a positive integer and [N] = {i contained in N | 1<= i <=N }  Let "Omega" C {(i,j) contained in [N] x [N] | 2<=i,j<=N-1} be a subset. Let V = R^([N]x[N]) be the vector space of real valued functions [N]x[N] -> R
and A, "triangle symbol":V->V (average) and "triangle symbole" (Laplacian) be the linear maps such that
[Af](i; j) = f(i; j)      if (i; j) not contained in "Omega"   OR

                             [f(i, j + 1) + f(i, j - 1) + f(i + 1, j) + f(i - 1, j)]/4 if (i,j) is contained in "Omega"

["traingle symbol"f](i,j) =  0 if (i,j) isnt contained in "Omega"   OR

                            ( f(i,j) - [f(i, j + 1) + f(i, j - 1) + f(i + 1, j) + f(i - 1, j)]/4 )    if (i,j) is contained in "Omega"

 Please and thank you for any help in advance <3

                           

 

error module is maple.dll_unloaded

 

i have already called stopmaple(kv);

in

testfunction(string hello){....stopmaple(kv));

 

testfunction(1);

testfunction(2);

when call testfunction again , it got error

The DirectSearch package is a powerful Maple  tool. However, every soft has its advantages and disadvantages. In particular, the DS has problems in the case of a thin feasible set in higher dimensions. Recently a serious bug in the DS was detected by me. Solving an optimization problem, the DirectSearch produces the error communication

Warning, initial point [x1 = 1., x2 = 1., x4 = 2., y1 = 2., y2 = 3., y4 = 2.] does not satisfy the inequality constraints; trying to find a feasible initial point
Error, (in DirectSearch:-Search) cannot find feasible initial point; specify a new one
 while that initial point satisfies the constraints.

 

restart

DirectSearch:-Search(((x2-x1)^2+(y2-y1)^2)*((x4-x1)^2+(y4-y1)^2), {seq(parse(y || j) >= -(2/3)*parse(x || j)+2, j = 1 .. 4), seq(parse(y || j) >= (1/2)*parse(x || j)-3/2, j = 1 .. 4), seq(parse(y || j) <= 4, j = 1 .. 4), seq(parse(y || j) <= -3*parse(x || j)+16, j = 1 .. 4), seq(parse(y || j) <= 2*parse(x || j)+2, j = 1 .. 4), (x2-x1)*(x4-x1)+(y2-y1)*(y4-y1) = 0, (x3-x2)*(x2-x1)+(y3-y2)*(y2-y1) = 0, (x4-x1)*(x4-x3)+(y4-y1)*(y4-y3) = 0, (x4-x3)*(x3-x2)+(y4-y3)*(y3-y2) = 0}, maximize, initialpoint = [x1 = 1, x2 = 1, x3 = 2, x4 = 2, y1 = 2, y2 = 3, y3 = 3, y4 = 2])

Error, (in DirectSearch:-Search) cannot find feasible initial point; specify a new one

 

eval({seq(parse(y || j) >= -(2/3)*parse(x || j)+2, j = 1 .. 4), seq(parse(y || j) >= (1/2)*parse(x || j)-3/2, j = 1 .. 4), seq(parse(y || j) <= 4, j = 1 .. 4), seq(parse(y || j) <= -3*parse(x || j)+16, j = 1 .. 4), seq(parse(y || j) <= 2*parse(x || j)+2, j = 1 .. 4), (x2-x1)*(x4-x1)+(y2-y1)*(y4-y1) = 0, (x3-x2)*(x2-x1)+(y3-y2)*(y2-y1) = 0, (x4-x1)*(x4-x3)+(y4-y1)*(y4-y3) = 0, (x4-x3)*(x3-x2)+(y4-y3)*(y3-y2) = 0}, [x1 = 1, x2 = 1, x3 = 2, x4 = 2, y1 = 2, y2 = 3, y3 = 3, y4 = 2])

{0 = 0, -1 <= 2, -1 <= 3, 2 <= 4, 2 <= 6, 2 <= 10, 2 <= 13, 3 <= 4, 3 <= 6, 3 <= 10, 3 <= 13, -1/2 <= 2, -1/2 <= 3, 2/3 <= 2, 2/3 <= 3, 4/3 <= 2, 4/3 <= 3}

(1)

``

 

Download opti.mw

I've just upgraded from Maple 15 to Maple 17, and discover that I cannot any longer write curly right braces in math mode. I use an international (Norwegian) keyboard, where curly right braces should be available by Ctrl+Alt+=, but nothing happens when I try to write this. I can work my way around it by using Copy and Paste, but this is inelegant, particularly when I want to demonstrate Maple for my class of 400 students.

Looking at older posts, I found this question, which concerns inline evaluation with international keyboard in Maple 16. Inline evaluation works fine for me, using Ctrl+Shift+=. So was this fixed at the expense of Ctrl+Alt+= ?

After disabling all security addons the Ajax gif loads, then it shows an error and after that it jumps to a page displaying "2013", but that page actually does not have any content (use ctrl + u to see it).

And the I see, that the browser tries to load from maplesoft.112.2o7.net and hangs up in that transfer (have not checked the ports).

In reality I would forbid to load from 2o7, as I receject almost all trackers.

But looking at Adobe http://www.adobe.com/de/privacy/analytics.html or others http://www.makeuseof.com/tag/that-mysterious-2o7-net-tracking-cookie-all-you-need-to-know/ those are 3rd party cookies (Omniture ---> Adobe)

Every reasonable person aware of security and xss forbids dubious sources from other websites (and I am not happy that this sites call Ajax at Google)

And if that is the reason for the bad behaviour of the new sites it would be a good joke, really.

For me it only works with IE and all its security issues (and I have to use "preview" before posting is possible)

bug in type...

October 21 2013 mois 323 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
                    ...

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...

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...

The second graph is incorrect. The reason?

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

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

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.

 

 

People:

 

I wrote a Maple 15 worksheet containing a function that calls two other functions defined earlier in the worksheet.  The main function didn't work, so I replaced one of the functions that was called, by cut-and-pasting its definition into the main function.  This is obviously inconvenient because I want to alter the function that I cut-and -pasted and whenever I do it I will have to cut-and-paste again.  It also detracts from the...

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: 

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