Can evalc be persuaded to return for

assume(x::complex):
+1/2*evalc(x + conjugate(x));
-I/2*evalc(x - conjugate(x));

the real and imaginary parts of x, respectively, i.e., Re(x) and Im(x). Further, can evalc be persuaded to let

assume(u::complex,v::complex):
evalc(Re(u)+Re(v)-Re(u+v));
evalc(Im(u)+Im(v)-Im(u+v));

return zeros identically? It does return zeros identically if either u or v (or both) is real-valued. But not if u and v are both assumed complex-valued. Why not?

Below is a link to a file I uploaded showing an example of using assigning the value obtained from eval() to a variable and then using evalf() versus using eval() inside of evalf(). The fact that there is some difference is not surprising; it's the sheer amount of difference that amazes me--up to 100%! Do also note that the difference "settle down" over time, which is to be expected. View 413_odd_rounding_example.mw on MapleNet or

Hi. Issue: Anytime I open a recently saved Mpl worksheet, all of my 2D-MATH has been erased and replaced with a simple question mark (?).. And I've tried to open it on a Linux-based OS and trying executing it for like a hundred time. Nothing seemes to work.. Solution needed. Thanks for your time and help. Vic

Is it possible to have installed both Maple 9.5 and Maple 11 without interference? The reason I ask instead of just trying it out myself is that when I tried to uninstall Maple 11 some days ago (in connection with my roll-back to Maple 9.5) it got stuck. So instead of risking that again, probably with some unfortunate consequences for the integrity of the registration database, I thought I might just ask your guys first. Some of you might wonder why I want to have both installed. But I thought that I might continue using Maple 9.5 for my usual research, and then using Maple 11, possibly in conjunction with a text editor, for things which cannot be done using Maple 9.5.

So I am trying to install Maple on OSX 10.5 and I am getting this error: Cannot launch Java application Uncaught exception in main method: java.lang.NumberFormatException: For input string: "TipCount" Any suggestions? I have a feeling it is not a problem with 10.5 but just a Java problem in general. Any help would be greatly appreciated! Thanks! Brandon

I have been trying to replicate the results of an analysis which uses elliptic integrals of the first and second kind (see an earlier post titled "Solve This! - Elliptic Integrals" for a copy of the analysis and a Maple worksheet that plots an equation containing an ellipitc integral). Dr. Israel provided the Maple commands that generate the plot; however, the results are not in agreement with the paper - not even close! In an attempt to validate the EllipticF(z,k) command in Maple, I have generated a spreadsheet (attached) which uses an EllipticAddin to generate a table of values for a range of phi from 1 to 45 degrees and theta over the same range. As you can see from the workbook, the Addin has successfully generated a table that is in perfect agreement to five decimal places with the results given on page 94 of "Elliptic Integrals", 1st Edition, by Harris Hancock, Wiley & Sons, 1917 (available in PDF format from Google). The sheet that uses the EllipticF(z,k) command is not in good agreement with the table from Hancock's publication.

Consider, just a test example, the following list of lists of positive integers ordered ascendingly

L := [[1,2,7,12],[3,4,5,6],[1,2,5,9]];

I would like this list of lists ordered so that [1,2,5,9] precedes [1,2,7,12], because 5 < 7 (the first two elements being equal), and [1,2,7,12] precedes [3,4,5,6], because 1 < 3. I think you see the general scheme. That can be achieved with the following code:

with(ListTools):
swapLists := proc(L1::'list'(posint),L2::'list'(posint))
   local L;
   L := MakeUnique(L1-L2);
   if L = [0] then
      false
   elif L[1] <> 0 then

In connection with setting attributes on Arrays, as discussed here, I have run into a problem which boils down to the following: why does the code (which is only for test purposes)

p1 := proc(x,y)
   table(['x' = x,'y' = y])
end proc:
p2 := proc()
   local x,y;
   x,y := 1,2;
   table(['x' = x,'y' = y])
end proc:
p1(1,2);
p2();

produce two different outputs; the former, p1, evaluates 'x' and 'y', even though they are surrounded by unevaluation quotes, while the latter, p2, does not?

When using matrix with real (non integers) coefficients, maple does significant mistakes. Does somebody knows why?

I present the following:

[> restart;
[> a1:= foo = bar;
                             a1 := foo = bar
[> a2:= blam = foo = bar;
Error, `=` unexpected
[> a3:= blam = a1;
                       a3 := blam = (foo = bar)

The fact that the definition of a2 (correctly) throws an error and the definition of a3 does not can lead to some odd errors down the way. I disagree with Maple's choice not to say that the assignment of a3 is in error.

Ok, I'm now using maple 11, previously i was using maple 8. I'm trying to define a coordinate array, in this case i do this by setting the array, Coords:=({x,y,z}); however maple 11 now seems to change the ordering of the array. giving as output: Coords := {y, z, x} How do I make it stay as x,y,z????? Why would it do this??

The student is supposed to use the logistic differential equation given to them (with carrying capacity .52e12), dsolve() the differential equation with a specific initial condition, and then calculate the population at 3 different times. Notice what happens:

[> restart;
[> my_deq := (diff(P(t), t))/P(t) = .789*(1-P(t)/(.52*10^12));

                   d
                   -- P(t)
                   dt                               -11
         my_deq := ------- = 0.789 - 0.1517307692 10    P(t)
                    P(t)

[> dsolve({my_deq,P(2290)=.83*10^10});

I am working on a new package, called "Spacetime", which I intend should be able to treat any physical field, either tensorial (integer-valued spin, like the photon) or spinorial (half-integer valued spin, like the electron) on any curved Riemannian manifold (gravity, according to Einstein). Anyway, for the Maple specific part: I have decided to implement these general fields as multi-dimensional Arrays, analogous to the older package "Gravitation", which "Spacetime" is intended to replace. They may have some symmetries and/or antisymmetries among their various indices. That part, that is, setting up the appropiate indexing functions, even in the general case, I have solved.

The following system of equations can be solved by Maple 9.5 and Maple 10, but either takes a long time in Maple 11 or else simply won't solve. Is anyone else experiencing problems with the solve command? Earlier I noticed that Maple 11 was returning duplicates in solutions, but this is more serious. We tried this system on Maple 9.5 and Maple 10, and it solves easily, but on two computers with Maple 11, in classic worksheet mode, minutes went by with no solution. {2*a[2,6]*a[2,9]-2*a[2,8]*a[2,9], 2*a[1,5]*a[3,1]+2*a[1,7]*a[3,1], 2*a[2,6]*a[3,4]-2*a[2,8]*a[3,4], 2*a[1,5]*a[2,1]+2*a[1,7]*

Under Maple 10, the command densityplot(10-x-y, x = 0 .. 3, y = -x .. x, scaling = constrained, colorstyle = HUE, style = patchnogrid)