Hye, have a good day everyone..

can anyone know why I got this error? :(second_grade.mw

Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system

Here I have attached the file. thank you in advance :)

Why can't I run a produce on the Maple IDE? I can't add Maple environment to Maple IDE. The error is this.

License expires in 29 days
|\^/| Maple 18 (X86 64 WINDOWS)
._|\| |/|_. Copyright (c) Maplesoft, a division of Waterloo Maple Inc. 2014
\ MAPLE / All rights reserved. Maple is a trademark of
<____ ____> Waterloo Maple Inc.
| Type ? for help.
Error: EnvUtils:-KernelSummary("could not validate license %1, required by %2. Please check the Install.html file under the toolbox directory for instructions on how to activate a license.\nLicense manager error: %3")
memory used=0.7MB, alloc=8.3MB, time=0.11

what means the command that `linsolve` and 

when

a:=matrix([[a1,a2],[b1,b2]])

b:=vector([c1,c2])

c:=transpose(a)

linsolve(c&*a,c&*b)

&* <<--- what is it

I need to make a lot of similar calculations and wonder if it can be done in a smart way in Maple. Microsoft Excel is perfect for this kind of calculations, because you can downcopy cells. I would like to do everything in Maple, if possible, though. I have a number of points A, B, C, D, E, ... , which all lie on various circles in the plane. For every point radius and angle is given, so actually you can say that every point is delivered with polar coordinates. I want to have their rectangular coordinates. 

Maybe I could deliver their radii in a list and their angles in degrees in another list?

r:=[12,56,29,...., 78]:

v:=[15,45,75,..., 102]: 

......

I need to be able to refer to a certain point thorugh an index. At best it would be A, B, C, ... , but 1, 2, 3, ... will be acceptable. So in the end I need to be able to access say x_C and y_C or x_3 and y_3 (understood as index lowered). I hope someone can help me do the task in a nice a efefctive way.

NB! Maybe you have a solution, which involve transformation from polar to rectangular coordinates. That will be nice, but please also tell me how it can be done from scratch, because I want to be able to know about handling many points at once for other purposes, when the function is not r*cos(v), but an arbitrary function.

Regards,

Erik

Is there any some kind of environment variable(or command,package, anything...) that I can play with to tell maple consider all the constrants implied by the given expression

For Example, I want to simplify the following equation(this equation's final form is "0=0" if you take the implied constraints into account.)

 "(4*a^3*b)^(1/2)/(-(a/(4*b))^(1/2))+(4*a^3*b*(4*b/a))^(1/2) = 0" 

in real domain and this equation implies that variable a and b are both negative or positive because of the sqrt operation. And neither a nor b should be zero because they are part of a fraction's denominator.

but if i simply tell maple to simplify this equation, all the constrants will be ignored by maple, even if i use RealDomain package.

My problem is the following; Let's say that I want to make a simple program of designing of a steel beam. In order to do so, there is a respectable number of parameters that have to be taken into account - forces, geometrical characteristics etc -. So for example, I have an excel file that has the following rows

1) A row of variables  :                          LENGTH   MOMENT_OF_INERTIA   AXIAL_FORCE    HEIGHT_OF_SECTION
 
2)A row of a value for each one variable :      5                556                       130                       300


the traditional approach in maple to intoduce these values to the program would be:

LENGTH:=5
MOMENT_OF_INERTIA:=556
AXIAL_FORCE:=130                etc etc

and then when for example we write

MOMENT_OF_INERTIA/LENGTH       we get

556/5=111.2

..but for problems like this the variables may be 50 in number, even more.. and it would be very timeconsuming to define all these parameters one by one..
so what I have been looking for so much these days is a predefined maple procedure - if there is one.. - that takes a matrix which we have created in advance and that includes all the names of the variables that we want to have in the problem - let's name it VARIABLES - takes as well a matrix that we also have created in advance and includes the value that we want each of our variables to get in the problem - let's name it VALUES - and make the correspondense automatically, so as to when we introduce an epression in maple thereafter, like     MOMENT_OF_INERTIA/LENGTH, when we press enter to get  556/5=111.2  (and not just a reproducing of what we already wrote , MOMENT_OF_INERTIA/LENGTH ..).. Do you think that there is an easy way to do so??

many thanks in advance!

I use Maple 15 to calculate some (nasty) integrals at my university. Because our university also offers a server on which I can run my Maple program, I would like to do that. (instead of occupying a workspace). But at the computer on my workspace the integrals are evaluated fine, but on the server the integrals are just returned with no numerical evaluation.

I constructed a MWE to look where it goes wrong. I set the printlevel to 25 so I could see what was going on. The MWE was suprisingly simple, on both machines (via ssh) I executed within maple:

This of course would normally just give 2*sqrt(2). On my workplace-pc it worked fine and it found 2.828427125. The server just returned the integral. After looking at the steps, they where both exactly the same until the following part:

Workplace-PC:

         General_flags := {_NoNAG, _DEFAULT, _NoMultiple}

            NAG_methods := {_d01ajc, _d01akc, _d01amc}

                        Method := _DEFAULT

                          HFDigits := 15

                                       -12
                        HFeps := 0.1 10

                                            -9
                    HFeps := 0.5000000000 10

   oldEvents := overflow = default, division_by_zero = default

                         callNAG := true

                            fcns := {}

                  result := 2.82842712474618807

Server:

        General_flags := {_NoNAG, _DEFAULT, _NoMultiple}

           NAG_methods := {_d01ajc, _d01akc, _d01amc}

                       Method := _DEFAULT

                         HFDigits := 15

                                      -12
                       HFeps := 0.1 10

                                           -9
                   HFeps := 0.5000000000 10

   oldEvents := overflow = default, division_by_zero = default

                         callNAG := true

                           fcns := {}

       overflow = exception, division_by_zero = exception

It seems that the server has a problem with the singularity and thus throwing an exception, but I just don't get why. The Maple-versions are both the same.

Does somebody know what this could be?

This might be a ridiculous question, but what is the easiest way to check the monotonicity of a function? I didn´t find anything helpful in the Maple Help, so maybe one of you could give me a nudge here :)

the following cmd gives me three 3 solutions: -1, 1,sqrt(2), even if I specificlly assume that a is not equal to neither 1 or -1....

([RealDomain[solve]((1/(a-1)-1/(a+1))*(2*a^2-2)/a = 4/surd(2, 2), useassumptions = true)] assuming a <> 1, a <> -1

why does this wired thing happen?

hi, the equations read as 

eq:=[2*x-0.2e-1*y-2.04*sqrt(-v^2+1)*v, 2*y-0.2e-1*x-2.16*sqrt(-u^2+1)*u, 2*u+2.16*u^2*y/sqrt(-u^2+1)-2.16*sqrt(-u^2+1)*y, 2*v+2.04*v^2*x/sqrt(-v^2+1)-2.04*sqrt(-v^2+1)*x] ;

i do as follows using DirectSearch package v.2

i find the solutions not the same,some time the results not much difference,but another,sols1 have one solution,sols2 have three solutions.in some time,some solutions are lost，the result show  me  random.may i have run the command serveral times? regards.

While I was using DEplot3d, I want to draw a space curve, the equation of which is a list of functions of the vars in DEs. I put them in "scene", but Maple told me this:

Error, (in DEtools/DEplot) Invalid scene; must be list of vars: scene = ...

Now I know that I cannot put functions in "scene", but I am wandering if there are some other way so I can draw this kind of space curve.

Thank you very much!

Hi there,

I am trying to compute the following, and I am getting this error.

> A := map(convert, M, unit_free)*Unit('m'*(1/'s'^2));
(I had to put the Unit('m'*(1/'s'^2)) because the original units were kNm/s^2 (kg), and even though I simplified it, it's still using kNm/s^2, and leaves the m/s^2 for some reason when I try to remove the units. I tried simply changing the units on the original matrix, but the units menu has disappeared from the right-click menu!!)

> B := map(convert, K, unit_free);

Loading RealDomain;

solve;

Error, (in assuming) when calling 'Engine:-Dispatch'. Received: 'should not happen: Rename expects the input to contain unknown functions'

Why is it giving me this error? omega is an unknown variable that I am trying to solve for. I am going a modal analysis, so maybe there is a better way to find omega?

Any help appreciated!

Raquel

I have document Maple.mw. I want to copy all text to mathtype. How do I copy and paste?

Link download: maple document

Why does the following not work?

factors(x^4-1)

Why does Maple 2015 solve this very simple system incorrectly?

solve({abs(a-b)=0, sqrt(2*b+c)=0, c^2-c+1/4=0});

With Maple 12 no problem:

solve({abs(a-b)=0, sqrt(2*b+c)=0, c^2-c+1/4=0});