I am trying to develop a solution to a problem which consists of taking a given vector field (force) and converting that field from one domain to another while maintaining an equivalent system of forces. The real world problem occurs in posttensioning design where steel tendons are place in concrete members and then a tensile force is applied to the tendon, which is then restrained at the end points, creating a compressive vector field in the concrete.

If I evaluate :

assume(0 <= a); full := integrate((sin(t)-t*cos(t))^2*cos(a*t)/t^5, t = 0 .. infinity)

I seem to be getting the wrong result. Not only does the expression look strange (imaginary parts for a real integrand), but it seems also to give wrong results e.g.:

I was reminded of this by another thread.

It is faster to add in-place a large size storage=sparse float[8] Matrix into a new empty storage=rectangular float[8] Matrix than it is to convert it that way using the Matrix() or rtable() constructors.

Here's an example. First I'll do it with in-place Matrix addition. And then after that with a call to Matrix(). I measure the time to execute as well as the increase in bytes-allocated and bytes-used.

> with(LinearAlgebra):

> N := 500:
> A := RandomMatrix(N,'density'=0.1,
>                   'outputoptions'=['storage'='sparse',
>                                    'datatype'=float[8]]):

> st,ba,bu := time(),kernelopts(bytesalloc),kernelopts(bytesused):

> B := Matrix(N,'datatype'=float[8]):
> MatrixAdd(B,A,'inplace'=true):

> time()-st,kernelopts(bytesalloc)-ba,kernelopts(bytesused)-bu;
                            0.022, 2489912, 357907

I reciently upgraded to maple 12, and am hoping it was not a mistake...  The "problem" is that now xmaple seems to have no clue as to the rules of precedence.  Before the upgrade (I was using 9.5) the expression 5/7*3 evaluated to 15/7 as it should.  Now, xmaple 12 thinks the answer is 5/21.

Is there some sort of download to fix this, or perhaps some "please evaluate using standard rules of precedence" setting I can use so that xmaple 12 is able to do arithmetic at least as well as the old 9.5 version?

 

 

Consider the following simple procedure

>F:=proc(LL::{set(list(integer)), list(list(integer))})
    LL;
 end proc:

 

Now execute this little loop

Hello Everyone,

This is more of a request for clarification than an actual problem:

I have written a procedure that involves multiplication, inversion (using LinearSolve) and eigenvalues/vectors (using Eigenvectors) calculations. The matrices are large (~3600 x 3600), consist of floating point complex numbers, and on occasion I need to hold several in memory at once. Therefore, I want to make sure that all of the calculations (and storage of resulting matrices) are done using double precision, not arbitrary precision, in order to minimise the memory usage.

A:=Matrix(2,3,1,datatype=float[8]);
                             [1.    1.    1.]
                        A := [              ]
                             [1.    1.    1.]

ArrayTools:-AddAlongDimension(A);

                               [2., 2.]

B:=Matrix(3,10,1,datatype=float[8]);

             [1. , 1. , 1. , 1. , 1. , 1. , 1. , 1. , 1. , 1.]
             [                                               ]
        B := [1. , 1. , 1. , 1. , 1. , 1. , 1. , 1. , 1. , 1.]
             [                                               ]

Can anyone explain the following (in Maple 11):

>maptype(set,evalf,[2.2222]);

 returns   [2.2]

whereas

>evalf([2.2222]);

 returns [2.2222]

My reading of the help page is that if [2.2222]  is not of type set (which it isn't) then maptype should return evalf([2.2222]);   It would seem that in this context, evalf is acting as evalf[2] independent of the prevailing Digits.

i have a computer with windows Vista and i saw that maple 7 doesn't work on vista.

so,I wonder if maple 7 worksheets and .mpl files can be read on maple 12 which works with Vista.

 

When I click on the help menu, Maple hangs for a second or two (spinning beach ball) before it shows the menu. None of the other menus exhibit this behavior, and the help system opens very quickly if I use the button on the button bar, rather than the menu. Is anyone else experiencing this? Any workarounds? Thanks, Paul ps, MacBook Pro, 2GB ram, OS X 10.5.2, 320GB hard drive.

Upgrading to Leopard introduced some conflicts with Maple 10 and 11, apparently arising from the new Java implementation. There are a few threads in this forum which address most of the issues. However, one has, for me, persisted, and I haven't seen it addressed anywhere else online, so I figured it might be good to start a topic.

...and the only way I found to recover is to kill Maple.

~Rich~

Hi everyone, i've got a strange question: I wanted to use monte carlo method to count the volume of the ball i 've choosen a [-1,-1], [1,1] square and ball of radius 1 to do it. i wrote something like this: with(Randomtools): k:=1000 Generate(list(rational(range=-1..1)+I*rational(range(-1..1),k)): map(abs,%): select(verify,%,1,'truefalse'('less_than')): evalf(nops(%)*4/k) the result is ok (3.14 in the first try ;) ), but I wanted to do a little "upgrade" and have written a little shorter formula: (now doing "abs" is not necessary) with(Randomtools): k:=1000

I have an embedded plot in View 1292_Embedded plot does not update correctly.1.0.mw on MapleNet or Download 1292_Embedded plot does not update correctly.1.0.mw
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I have found that once I have "ugraded" to AVG Free 8 (the antivirus of Grisoft) Maple 12 Classic GUI no longer finishes starting: the splash screen remains, the red button is on, pressing it issues "You are in the middle of a computation. Do you wish to interrupt it?". Pressing it gives me a non responsive GUI. And the task manager is required to kill the zombie proceses that remain after closing the GUI.