Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

es posible obtener la función del contorno de un dominio convexhull ?

 

 

 

Sorry for the uninformative title. I've never used Maple, but I'm willing to buy a student license and learn it. But before spending too much effort and money I need to know if it suits my needs.

Basically what I need to do is:

1) I have a positive definite symmetric matrix of size nxn, where n can range from 2 to inf. I don't know the elements, except the fact that the diagonal has ones everywhere. All I know is that the elements out of the diagonal are in the range [0,1)

2) I have to compute the lower triangular cholesky decomposition of this matrix, lets call it L.

3) I need to subtract from each element of L the mean of the elements in the respective column. Lets call this matrix L*

4) Then I need to evaluate another nxn matrix computed from the elements of L* following a simple pattern.

5) Finally I need to find the eigenvalues of this last matrix.

What I would ideally want is to get a symbolic representation of the n eigenvalues as symbolic functions of the (unknown) elements of the matrix at point 1.

I can drop the assumption of n being unknown, i.e. fix n=3 and get the 3 functions that, after replacing the right values, give me the eigenvalues, then fix n=4 and get 4 functions, etc.

Is this possible to do in maple?

Thank you

Hello,

I try to use a Catmull-Rom spline which has to match on several points.

I use a code extracted from the book "Geometry and curves with maple".

Here you can find an extract which is visible from google book :

I have slightly modified the initial procedure crom_2d. I didn't find the error in my procedure. May you help me to find the blocking point of my procedure ?

Here I attached my code:

CalculSplineMatmull-Rom.mw

Thank you for your help.

I never expected that the reflected light direction of sun from moon in the sky would be so dificult to imagine ...

at the following article mentioned :

we derive an equation for the magnitude of the moon tilt illusion that can be applied to all con gurations of sun and moon in the sky.

THE MOON TILT ILLUSION

 

since the calculations contains many steps and high level mathematical formula , there is no way rather to recourse to maple (powerful math assistant )

I hope there was adaptations between a lots of functions and predefined schema of maple and this problem so that the calculations and visualization facilitated several times ?

your effort will be a graet present for all the people of the world that look to the moon crescent everytime !

 

I have some preferences for viewing. Specially, I prefer atomic variables to be showed with a different color. So I check mark the related option for this in the view menu. But every time I close and reopen the Maple, it just restore my setting for atomic variables. Suprisingly, this does not happen for other viewing options in the view menu! What should I do? Why is it like this?

                                                                                 

Hi everybody,

I have some experimental data from an oscillating system (time domaine) and I would like to get an approximation of the damping ratio (zeta). I have already try to use the half-power band width method with the vibrationdata Matlab package designed by Tom Irvine. But I would like to double-check the result with another method.

I found several methods in this paper and I would like to try to do the curve fitting method with the Curve Fitting Toolbox of Maple or Matlab (R2014b) (2.2.2 Curve fitting in the paper). data.txt

It's the first I use this Toolbox with a custom equation, so, I do not really know how to do it with my sample data.

Can anybody help me with this ? I have attached the .txt file sample data to this post.

Cheers

Hi,

 

I was wondering how to go about plotting a Fourier Tranform in Maple.

My assignment is to plot a simple harmonic equation as a Fourier transform, depicting amplitude against fequency.

I've been given: x'' + w^2 x = 0

And want to obtain both the f(x) = a0 sin(wt) + b0cos(wt) form, and a graph of the the amplitude (c^2 =a0^2 + b0^2) against frequency.

I know how to do this on paper but not in Maple, so any help with line commands and layout would be very much appreciated.

 

Thanks

PrimesQuestion.mw

Please let me know if this link correctly accesses my worksheet. If not, I will copy its contents into this question.

Which ODE in the worksheet, if any, provides the correct answer?


restart

f := proc (x) local t; if not type(evalf(x), 'numeric') then ('procname')(x) else evalf(Int(exp(-(1/10)*t^2), t = 0 .. x)) end if end proc

solA := dsolve({diff(y(x), x) = y(x)+f(x), y(0) = 0}, numeric, known = f)

solA(1)

[x = 1., y(x) = HFloat(0.7081492947996167)]

(1)

f2 := evalf(Int(exp(-(1/10)*t^2), t = 0 .. 1)); f(1)

.9676433126

 

.9676433126

(2)

solB := dsolve({diff(y(x), x) = y(x)+f2, y(0) = 0}, numeric, output = listprocedure)

solB(1)

[x(1) = 1., (y(x))(1) = HFloat(1.6626837619970016)]

(3)

YinSolB := subs(solB, y(x))

YinSolBeval := solve(YinSolB(a) = .7081, a); solB(YinSolBeval)

.5491485953

 

[x(.5491485953) = .5491485953, (y(x))(.5491485953) = HFloat(0.7081000000284681)]

(4)

NULL


 

Hi,

I'm trying to work out whether or not Maple will be able to help me out with some algebra involving lots of indices, but I can't seem to work out how the gauge indices features work in the Physics package. For example I would like to define a gauge field carrying an SU(3) index and a spacetime index. The SU(3) index should run from 1 to 8 and the spacetime index from 1 to 5. I think I have worked out how it works with spacetime indices but I can't seem to find any documentation on the gauge indices.

Is there are a way to set the "dimension" of the gauge index, like we can set the space time dimension?

 

Cheers

Hi,

  I would need to get access to the values of euler angles defining the orientation of a 3D plot.

I generate the 3D plot with a given orientation, then the user is allowed to rotate it with mouse orbit. How can I get the values of the new euler angles to use them in further computations?

In the plot/structure I cannot find any data concerned with orientation...

 

Thank you.

 

Marco

I have the following equation:

Diff(W(t), t) = -q*V*(sin(Phi)-sin(Psi[s]))/(2*h*Pi);

I solve it for rhs() = 0:

soln := solve([rhs((2)) = 0, Phi < 2*Pi], [Phi], allsolutions = true,explicit);

This works and I get this result:

Now I want to get the first zeros, which occur for _Z1 and _Z2 equal to 0. So I substitute:

subs(_Z2=0,(3));

and get

In other words, the substitution did not work.

The original problem is embedded in a larger sheet created with Maple 15 and there it does work. It fails on Maple 2015.2. I then pulled out the relevant pieces to make this example demonstrating the problem (see the attached sheet, which has some of my other (unsuccessful) attempts to diagnose what is going on). It seems like the created variables _Z1 and _Z2 are somehow not recognized at all.

The only way I can get the _Z2 terms out is to substitute 2=0. This is really too icky to seriously consider, though.

Anyone has seen this before?

FWIW: Maple 2015.2 on Mac OS X 10.10.5.

Thanks,

Mac Dude

Assumptions_test.mw

Hi,

 

I have an issue calculating an electronics circuit with Maple, using units. I have a current source that I know, and I want to determin the voltage in a capacitor by solving an ODE (except that the current source is defined piecewise). And to make sure I have all the units and scales right, I use the standard unit package. All my variables have their units defined.

Except that Maple doesn't want to solve the equation. It seems to me that it assumes that the function I am trying to solve is unitless, and therefore refuses to solve. 

V__out := 3*Unit('kV');

C__out := 2*Unit('nF');
R__blead := 520*Unit('`k&Omega;`');

I__fly := proc (t) options operator, arrow; Unit('A')*piecewise(t < 3.25*Unit('us'), (1+(-1)*t/(3.25*Unit('us')))*.2, 0) end proc;

 

dsolve({I__fly(t*Unit('s'))-V__C(t*Unit('s'))/R__blead = C__out*(diff(V__C(t*Unit('s')), t)), V__C(0*Unit('s')) = V__out}, V__C(t*Unit('s')));
Error, (in Units:-Standard:-+) the units `A` and `S` have incompatible dimensions

 

Is there a way to make Maple assume the unit of what it's trying to solve ? I need it to understands that V__C is in Unit('V') ...

 

Thanks

 

hi .by changing amount of variable such as '' f '' or 'D5 ' in input data, not changing  in final result!!!!please chek attached file 

thanksX4.mw

I have Maple package "DESOLVE" having two different types of files namely in format .mpl and .mws, where code is written in .mpl file and .mws is just a example worksheet, this package is available at following link;

http://cpc.cs.qub.ac.uk/summaries/ADYZ_v1_0.html

My problem is how to work with package?

One thing that I able to do is that I have opened the file type .mpl  in Maple worksheet and after executing whole whorsheet I able to to start working with package using with(desolv).

But when I type with(desolv) in new worksheet an error shows up.

How I can store this .mpl file in Maple library so as to use this package using "with(desolv)" in new worksheets

Desolv_worksheet_paper.mws?

Hello,

 

Remark by Markiyan Hirnyk:

The part of the body of this question disappears after my edit of its title only.

First 175 176 177 178 179 180 181 Last Page 177 of 334