Good afternoon. As a function of ImpulseResponsePlot set the pulse? for example, 1 millisecond or 10 microseconds. Whether it is possible to set the duration?

How can I introduce an arbitrary 4D metric in GRTENSOR, to calculate various components of corresponding Riemannian Tensor Components.

Dear readers,

I want to assign a name, say Lett with D (not the string "D", just the symbol D). I cant do that thoug I already use the command 'unprotect(D)':

> unprotect(D);
   Lett:=D

How can I be succeeded to do it?

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

What is going on here?

Does anybody use maple 17 in the Mac's Mavericks OS? Or it does not support the new OS yet.

It seems in the sysytem requirement of maple 17, it said only supports OS 10.7, 10.8.

Hi all

I have following program to solve time delay system...

the solution is good by choosing r:=11... but for r greater than 11(e.g r=20) the system take about4-5 minute to do and then it says:"" K2:=simplify(inverse(K1)):Error, (in minor) object too large""
and for plotting says:""     Warning, unable to evaluate 1 of the 2 functions to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct""

i don't know what is the problem?

any one can help me???

best wishes

> restart:
> with(plots):
> with(linalg):
> with(LinearAlgebra):
> L:=1:
> r:=20:
> tau:=0.3:
> #definition of exact solution
>
> T1 := piecewise(t<0,0,t>=0 and t<0.3,1+t^2,t>=0.3 and t<0.6,(691/1000)+(109/100)*t+(7/10)*t^2+(1/3)*t^3,0.6<=t and t<0.9,(4409/5000)+(209/500)*t+(69/50)*t^2+(2/15)*t^3+(1/12)*t^4,0.9<=t and t<1,(1500917/2000000)+(35107/40000)*t+(1617/2000)*t^2+(87/200)*t^3+(1/120)*t^4+(1/60)*t^5):
> plot(T1,t=0..1,numpoints=10000,discont = true):
> g:=t^2:
> a[0]:=evalf((1/L)*Int(g,t=0..L)):
> for i1 from 1 to r do
> a[i1]:=evalf((2/L)*Int(g*cos(2*i1*Pi*t/L),t=0..L)):
> od:
> for j1 from 1 to r do
> b[j1]:=evalf((2/L)*Int(g*sin(2*j1*Pi*t/L),t=0..L)):
> od:
> X00:=matrix([[a[0]]]);
> X10:=matrix(1,r,0):
> for j from 1 to r do
> X10[1,j]:=a[j]:
> od:
>
> X20:=matrix(1,r,0):
> for j from 1 to r do
> X20[1,j]:=b[j]:
> od:

X00 := [0.3333333333]

> X00:=blockmatrix(1,3,[X00,X10,X20]):
>
>
>
> Z:=linalg[matrix](2*r+1,2*r+1):
> Z[1,1]:=tau:
> for iz from 2 to r+1 do
> Z[iz,1]:=(L/(2*(iz-1)*Pi))*sin(2*(iz-1)*Pi*tau/L):
> od:
> for iz from r+2 to 2*r+1 do
> Z[iz,1]:=(L/(2*(iz-1-r)*Pi))*(1-cos(2*(iz-1-r)*Pi*tau/L)):
> od:
> for jz from 2 to 2*r+1 do
> for iz from 1 to 2*r+1 do
> Z[iz,jz]:=0;
> od:
> od: 
> Dtau00:=matrix([[1]]):
> Dtau01:=matrix(1,r,0):
> Dtau02:=matrix(1,r,0):
> Dtau10:=matrix(r,1,0):
> Dtau20:=matrix(r,1,0):
>
> Dtau1:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> Dtau1[i,i]:=cos(2*(i)*Pi*tau/L):
> if i<>j then Dtau1[i,j]:=0 fi:
> od:
> od:
>
> Dtau2:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> Dtau2[i,i]:=sin(2*(i)*Pi*tau/L):
> if i<>j then Dtau2[i,j]:=0 fi:
> od:
> od:
>
> Dtau3:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> Dtau3[i,i]:=-sin(2*(i)*Pi*tau/L):
> if i<>j then Dtau3[i,j]:=0 fi:
> od:
> od:
>
> Dtau4:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> Dtau4[i,i]:=cos(2*(i)*Pi*tau/L):
> if i<>j then Dtau4[i,j]:=0 fi:
> od:
> od:
>
> Dtau:=blockmatrix(3,3,[Dtau00,Dtau01,Dtau02,Dtau10,Dtau1,Dtau2,Dtau20,Dtau3,Dtau4]):
>
> P00:=matrix([[L/2]]):
> P01:=matrix(1,r,0):
>
> P02:=matrix(1,r,0):
> for j from 1 to r do
> P02[1,j]:=-L/(j*Pi):
> od:
>
> P10:=matrix(r,1,0):
>
> P20:=matrix(r,1,0):
> for i from 1 to r do
> P20[i,1]:=L/(2*i*Pi):
> od:
>
>
> P1:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> P1[i,j]:=0
> od;
> od;
> P2:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> P2[i,i]:=L/(2*i*Pi):
> if i<>j then P2[i,j]:=0 fi:
> od:
> od:
>
> P3:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> P3[i,i]:=-L/(2*i*Pi):
> if i<>j then P3[i,j]:=0 fi:
> od:
> od:
>
> P4:=linalg[matrix](r,r):
> for i from 1 to r do
> for j from 1 to r do
> P4[i,j]:=0:
> od:
> od:
>
> P:=blockmatrix(3,3,[P00,P01,P02,P10,P1,P2,P20,P3,P4]):
> I1:=Matrix(2*r+1,shape=identity):
> K1:=simplify(evalm(I1-Dtau&*P+Dtau&*Z)):
> K2:=simplify(inverse(K1)):
Error, (in minor) object too large

>
> X0:=matrix(1,2*r+1,0):
> X0[1,1]:=1:
> for j from 2 to 2*r+1 do
> X0[1,j]:=0:
> od:
>
> X:=simplify(evalm(evalm((X0+X00))&*K2)):
>
> for h from 1 to r do
> f1(h):=cos(2*h*Pi*t/L):
> od:

> for k from 1 to r do
> f2(k):=sin(2*k*Pi*t/L):
> od:
> XP:=X[1,1]+evalf(sum(X[1,l+1]*f1(l)+X[1,r+l+1]*f2(l),l=1..r )):
> plot({XP,T1},t=0..1);
Warning, unable to evaluate 1 of the 2 functions to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

Hi everybody,

Suppose that in an equation, I have the term x^/(t).  I want to substitute it by v(t).  Any suggestion because I am trying but don't find an help page on this.

Thank you in advance for your help!

--------------------------------------
Mario Lemelin

Maple 17.01 Ubuntu 13.10 - 64 bits
Maple 17 Win 7 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987

Hi, 

In maple I have:

> evalf(Re(BRW(10.))); evalf(Re(BRZ(10.))); evalf(Re(BRF(10.))); evalf(Re(TOT(10.)));
0.07948364664
0.08085621836
0.8395727755
2.006454216 10 ^{-36}

Now , when I want to print maple give me problems:

file:=fopen("/home/nicoviaux/Post-Doc/BRT4.txt",WRITE):
try
for i to 3 do
fprintf(file,"%g %g %g %g\n",i/10.0,evalf(Re(BRW(i/10.0))),evalf(Re(BRZ(i/10.0))),evalf(Re(BRF(i/10.0)))):
od
end try:
Error, (in fprintf) number expected for floating point format
fclose(file):

Someone have an idea for this?

Thanks

I want to collect a two terms expression x/2+y/2.

But, I cannot do it as follows.

> x/2+y/2;

> normal(%);

>factor(%)

result was 1/2*x+1/2*y.

With which can I have maple modify the above expression to (x+y)/2.

Thank you in advance.

taro

what is the name of this decomposition?

Y = S^-1*X*S, where S is unitary fourier transform

do maple have function to solve this?

I want to solve following PDE question with forward difference method inn Maple. Can you help me please?

du/dt=d^2u/dx^2, 0<x<2, t>0

u(x,0)=sin(2*pi*x)

u(0,t)=0, u(2,t)=0

Use h=0.4 and k=0.1. and compare your answers at  t=0.5 to the exact solution u(x,t)=exp(-4*pi^2*t)*sin(2pi*x). Then use h=0.4 and k=0.05,and compare the answers. 

How to calculate a matrix's self adjoint matrix if given any matrix?

<Px, y> = <x, Py>

hermitian is a kind of self adjoint

L:=Matrix(H,shape=hermitian);

is above command convert a general matrix H into self adjoint L?

any other methods

Greetings to all.

The multiplicative partition function is defined here at Wikipedia and was recently the subject of a discussion at Math Stackexchange.

I posted two solutions to the task of computing this function at the above page that use Maple code. One of them employs the Polya Enumeration Theorem and is of mostly theoretical interest as it cannot be used to effectively compute the function for n with many factors. I posted two additional implementations in order to remedy this defect, one of them in Maple and the other in Perl. I think the Maple implementation is easy enough to read not to require additional commentary. Note, however, that even though the Maple code and the Perl code implement the same algorithm (dynamic programming), the Maple version is dramatically slower than the Perl version and consumes a lot of memory. E.g. Maple takes 58 seconds for the value for 9! and Perl takes 1.5 seconds.

My question is, can someone explain this difference? Note that both are interpreted languages so there is no gain due to potential compilations.

Your commentary is appreciated.

This is with Maple 15 (X86 64 LINUX).

Best regards,

Marko Riedel

Both eval and showstat show that a procedure `print/diff` exists, but I am having trouble figuring out when the procedure is invoked. I expect it to be invoked---like any other `print/` procedure---when diff is output as an unevaluated function call. So I enter,

debug(`print/diff`);
diff(f(x), x$2);

This does not produce any debug output. Why? Checking with lprint shows that the result does indeed contain diff as an unevaluated function call.