Hello,

I want plot this equations with values independents x,A,B

But this is error.

Any idea?

Thanks

I resolved the coefficients to a 2nd order diff eq of the form:ay''+by'+cy=f(t)

I have included the .mw file for convenience at the link at the bottom of the page.  I resolved the coefficients in 2 different ways & they do not concur.  The 1st approach used the LaPlace transform & partial fraction decomposition.  The coefficient results are given by equations # 14 & 15.  The 2nd approach used undetermined coefficients where I assumed the particular solution and then applied the initial conditions to resolve the coefficients pertaining to the homogeneous solution which are given in the results listed in equation #23.  Noted in the 1st case the coeff's are A₃ & A₄ and for the 2nd approach the coeff's are A₁ & A₂.  I have worked this numerous times & do not understand why they do not concur.  So I thought I should get some fresh eyes on the problem to find where I may have gone wrong.

Any new perspective will be greatly apprecieated.

I had trouble uploading the .mw file so I have included an alternative link to retrieve the file if the code contents is illegible or you cannot dowlad the file drectly from the weblink  Download coeffs_of_homogen_soln_discrepancy.mw.  You should be able to download from the alternative link below once you paste the link into your browser.  If you cannot & wish for me to provide the file in some other fashion respond with some specific instructions & I will attempt to get the file to you.

https://unl.box.com/s/dywe90wwpy0t4ilkuxshkivz2z26mud8

Thanks 4 any help you can provide.

Download coeffs_of_homogen_soln_discrepancy.mw

I need to implement gaussian elimination with cross multiply. I followed the method decribed in the textbook, however the result returned a wrong determinant. I noticed that cross multiplication changes the determinant in every step. Does anybody know how to use the cross multiplication without altering the determinant?

I cannot seem to upload my .mw file.  What is going on with the this new MAPLEPrimes?  I need some help getting my file uploaded.  What other avenue is available?

Find the first 6 non-zero terms of MacLaurin series of the function erf(x)

Consider the expression ∑_n=1 (-1)ⁿ e^*n/n²

1. Find the symbolic value of this sum.

2. Find an approximation for the value when  = -2.

3. Build a function to calculate an approximation for the value of the given expression for

any value for 

Hi all, first poster just getting to grips with Maple here. I am having some problems with the 'verify' function in Maple - I can't understand why it is returning 'FAIL' An example of my printout is given below. 

> verify( 2*q/(q^4+q^2+1)-1/((q-1)^2*(q+1)), 0, 'greater_equal') assuming q>7;

                                             true

> verify( (2*q+1)/(q^4+q^2+1)-1/((q-1)^2*(q+1)), 0, 'greater_equal') assuming q>7;

                                             FAIL

Now it's th second line i'm interested in and it was only after trial and error that i found the first option worked. The fact the 1st does but 2nd doesn't makes no sense to me. Perhaps it's something stupid i'm missing - any help would be great. Thanks.

Dear all,

I'm investigating the vibration performance of timber beams. I have sample data from my test which shows the vibration of the beam. I want to determine the eigenfrequency from this data. The problem I face is that I'm not finding the probber eigenfrequency. I have two data rows; time and amplitude. I'm able to plot the amplitude with SignalPlot but not the time, therefore I have to adjust the samplerate. I have the same problem with the fourier analysis. Is it possible to include the time period as well?

Regards,

Maurits

Hello,

I need a bimodal distribution. Since I could not find any among the ones provided by Maple, I created a simple one:

with(Statistics):
U := Distribution(PDF = (proc (t) options operator, arrow; piecewise(t < -5, 0, t < 5, -(1/2000)*t^4+(9/1000)*t^2+7/80, 0) end proc)):
X := RandomVariable(U):

#Plotting PDF and CDF works fine:
plot(PDF(X, t), t = -infinity .. infinity);

plot(CDF(X, t), t = -infinity .. infinity)

However, plotting the quantile function does not work:

plot(Quantile(X, z), z = 0 .. 1);

it has a decreasing part for z<1/2 and a discontinuity at z=1/2.
I can plot it correctly as
plot('Quantile'(X, z), z = 0 .. 1);

but I wonder why the first option does not work for such a simple distribution.

I have a trouble of Maple.
I can't understand the solution of Maple for simplification of Dirac and Heaviside functions.

I wrote the below code,

"restart:
simplify(Dirac(x)*f(x))".

Then, Maple return the answer of this code, "Dirac(x)*f(0)".
I could understand this solution, then I rewrote the next code,

"restart:
_EnvUseHeavisideAsUnitStep:=true:
Heaviside(0)"

Then, Maple returned "1", because I set the value of Heaviside's step function H(x) at x=0.
Finally, I wrote the below code, but there was a problem, I think.

"restart:
_EnvUseHeavisideAsUnitStep:=true:
simplify(Dirac(x)*Heaviside(x))"

The solution of Maple was "0".

According to my first code, I think this solution is Dirac(x)*Heaviside(0), that is, Dirac(x).
I can't understand this result.
Someone help me, please.

Dear all,

I need to transforme these equation from time domain to frequency domain with fourier transforms and solve it in frequency domain but i received the flowing error

any helps

thank you !

Code :

Download Fourier_TRAns_MAPLEprime.mwFourier_TRAns_MAPLEprime.mw

I am interested to perform taylor expansion

f(x,y)=sin(x+y)+y

at (0,0). How we perform this in maple?

Bear with me, while I've used Maple V, I've never done any actual programming in Maple as I've almost entirely used Matlab.  Right now I've got an issue with trying to fill a square matrix using a sinc function [(sin(Pi*x)/(Pi*x)].  Here's my procedure:

Note that the arguments for sin and for the denominator are written as they are so as to define the domain of  the sinc function as [-m/2,m/2] along a row and [-n/2,n/2] along a column of the matrix I want to fill and so that I the arguments can have decimal values.  Also note the conditional statements there because when the sine argument and the denominator yields Pi*0, the function equals 1 despite the zero in the denominator.

So I'm unsure how to fill a matrix of some size m x n using the procedure (or a function if that makes the programming easier).  Here's how I would write the code for Matlab:

Z=zeros(2001,2001);
X=(-5:.005:5)';
Y=(-5:.005:5)';

count1=1;

for j=-5:.005:5
    count2=1;
    for k=-5:.005:5
        Z(count1,count2)=sinc(k)^2*sinc(j)^2;
        count2=count2+1;
    end
    count1=count1+1;
end

Given my meager experience writing Maple code, I'm a bit flumoxed.

Thanks, and don't feel like you have to be gentle. No one ever accused me of writing elegant code.

Thanks

Dears;

Hope everyone is fine. I am try to find the numerical solutions of system of nonlinear algabric equation via newton's raphson method in the attached file but failed. Please see the attachment and try to correct. You can solve it least square method if possible. I am waiting your positive response. 

Help_in_Newton.mw

With my best regards and sincerely.

Muhammad Usman

School of Mathematical Sciences 
Peking University, Beijing, China

Email: muhammadusman@pku.edu.cn

Hi, I'm trying to use Maple to construct some examples of symmetry solutions for certain nonlinear PDE's.  As a warm up, however, I'm working through the commands just for the heat equation in 3d: u[t]-u[x,x]-u[y,y]-u[z,z]=0 

I've gotten Maple to produce both determining equations for the symmetry infinitesimal generators via the DeterminingPDE command.  I've also gotten the command Infinitesimals to work too.

However, when I next use PDETools Invariants command, it correctly outputs invariants for most of the generator output of Infinitesimals EXCEPT it won't output anything for the simple rotation generators yd[x]-xd[y].  It will, however, output invariants if the rotation is between an independent and the dependent coordinate.

An example:
with(PDETools)
S:=[_xi[x]=y, _xi[y]=-x, _eta[u]=0]
Invariants(S,u(x,y))

*Above returns nothing, But if you instead have _xi[x]=x and _xi[y]=y then it returns the right invariants.

Thanks in advance!