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Dear Sirs,

I actually rigoruos to know what is the algorithm of BVP[midrich]? how it can obtain the solution of ODE with singularities?

 

Did anyone introduce a reference about the algorithm like this?

Thanks for your attention in advance

Amir


s,k,mu,sigma are parameters.k is real number

Hi

I am trying to compute the value of a complex integral with higher precision, but if I increase the number of significant digits the value is not computed. Are there any approaches that can give me higher precision?
Residue calculus does not appear to be an option but as the exponents are not necessarily integer.

The problem is the following:

int_C(phi(z)*exp(-l*z))intd z

where C can be parametrized by t->mu+t+c*I*t for t=0..infinity, mu and l is real.

Dear friends,

I ran into another problem while using Maple to do residue calculus. The following call

residue(1/x^(1/3)/(x^2+2*x*cos(phi)+1), x=-exp(I*phi));

returns zero -- it does not recognize the residue. On the other hand, if I do a subsitution like this

subs(x=-exp(I*phi), 1/x^(1/3)/(x^2+2*x*cos(phi)+1));

followed by

convert(%, trig); simplify(%);

then I get a divide by zero error, which shows that the...

Hello all,

I have a square singular matrix E (12x12), and a matrix A (12x12). I need to find a matrix R (12x12) such that A = E. R. RT .ET 

How can I use Maple to find the matrix R?

Thank you so much,

STHence

Hello all,

I have a singular square matrix E (12x12 with its rank of 10). I need to find 2 invertible matrices S and T such that S.E.T is a square diagonal matrix (in Smith Normal form). 

Using Maple with the following commands:
>Temp := SmithForm(E);
>Rank(Temp) 
Temp is a identity Matrix and Rank of (Temp)  is 12!!! or Rank of (S.E.T) = 12.

However, the determinant of E is less than 10^-29 and rank of E is 10.

Hi everyone,

 

I want to create a Gaussian PDF so I need to calculate Determinant(sigma) with sigma the covariance matrix of a gaussian variable.

If we call this variable alpha (which is a 12 dimension vector and represents the noise in a discrete dynamical equation), then sigma_ij=ExpectedValue(alpha_i*alpha_j)-ExpectedValue(alpha_i)*ExpectedValue(alpha_j)

and this is zero most of the time! So the covariance matrix is singular and the determinant is zero. 

Dear all

How to avoid in plot "matrix in singular" in my pde system

> a1 := -2;
-2
> b1 := 3;
3
> c1 := -1;
-1
> L := 15;
15
> b := .25;
0.25
> th := 1.5;
1.5
> pde := diff(u(x, t), x, x, x, x, t...

Which algorithm does maple follow for singular value decomposition by command 'SingularValues' in LinearAlgebra Package ?  Is it is QRSVD or divide and conquer or any other   .As far as  I know, MATLAB uses QRSVD.

Error Maple 15,...

September 02 2011 MySelf19 10

Hello,

 

I have an error in Maple 15, I dont understand why it doesnt work. I mention that in Maple 13 it works:

 

The code is

  L:=4:

sum(diff( (x^2-1)^l,x$l),l=0..L);

 

The error is:

Error, (in SumTools:-DefiniteSum:-ClosedForm) summand is singular in the interval of summation

 

Somebody can help me, please?

Thank you

Hello,

I am trying to solve the following differential coupled system :

 

DN:=diff(N(x),x)=a/4*(x+8*(sin(F(x)))^2/x)*N(x)*diff(F(x),x)^2;

Du:=diff(u(x),x)=a/8*((x^2+8*(sin(F(x)))^2)*(1-u(x)/x)*diff(F(x),x)^2+2*(sin(F(x)))^2+4*(sin(F(x)))^4/x^2);

DDF:=diff(F(x),x$2)=1/(N(x)*(1-u(x)/x)*(x^2+8*(sin(F(x)))^2))*(-(x^2+8*(sin(F(x)))^2)*diff(N(x),x)*(1-u(x)/x)*diff(F(x),x)+(1+4*(sin(F(x)))^2/x^2+4*(1-u(x)/x)*diff(F(x),x)^2)*N(x)*sin(2*F(x...

 

Download for_mapleprimes.mw

I used dolve for dsystem,

but I got this error:cannot evaluate right than .....

is there anyway to overcome this problem?

thanks

For educational purposes, I was experimenting with the Fourier series expansion of periodic functions. Following the definition for 2pi-periodic functions on Wikipedia, given by

 

 

and

 

Hello all,

I have encountered a curious bug in the EigenConditionNumbers
procedure. In particular for a pencil pencil (A,B) with B singular,
and precision higher than hardware precision.

The following code for Digits=40 produces a Float(undefined) rather
than a Float(infinity) for the infinite eigenvalue, but an alpha and
beta that will produce an infinite eigenvalue.

Digits:=trunc(evalhf(Digits));
A:=Matrix([[1,0],[0,2]]);
B:=Matrix([[1,0],[0,0]]);

Can I solve the following two coupled differential equations instead of the previous one in Maple 13?

 with plots

Eq[1]:=3*f(eta)*(diff(f(eta), `$`(eta, 2)))-2*(diff(f(eta), eta))^2+3*g(eta)

Eq[2]:=(diff(g(eta), `$`(eta, 2)))/Pr+f(eta)*(diff(g(eta), eta))

BCs := [f(0), (D(f))(0), g(0)-1, g(25)]

pars := {Pr = 1}

for i to 2 do eq[i] := subs(pars, Eq[i]) end do

eqs := eq[1], eq[2]

vars := f(eta), g(eta)

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