When Benoit Mandelbrot was still alive I sent him an email:

Hi,
I am writing to you because I have trouble understanding why
the covariance function in the Fractional Brownian Motion (FBM) is given by:

(t[i]^(2*H)+t[j]^(2*H)-abs(t[i]-t[j])^(2*H))/2)

I would be very grateful if you could please explain this to me in simple and step by step terms.
I understand simple ARIMA models (P(t)=P(t-1)+E(t) where E(t)=p*E(t-1)+r(t)) which have the
same...

Hey, so i guess i dont really know whats going on. I am trying to install Maple 10 on my Macbook Pro. I get an error message Uncaught exception in main method: java.lang.NoClassDefFoundError: org/apache/crimson/parser/XMLReaderImpl when i try to open the program. Any help?

Assume that we have a vector-function:

After calling define_external from maple library succefully loaded. But how to unload it without closing maple? For example want change library file to new one.

Dear guys!

I'm solving an equation and then by its results I solve an integral, but I'm doing that for many initial conditions in a for loop. The problem is that when I change the limits of loop (or initial conditions) the result of integral in two for loop for a same initial condition are very different. What's the problem?

Thanks!

Hello, I'm having trouble running my worksheet on my computer, don't know why but the Solve commands just never give me output, even with easy equations.

If someone could please run this worksheet FormulasToSolve_2.mw   for me I would be greatly thankfull, I'm stuck in my research because of this...

1. can it have simple solution for convert(taylor(Qx*exp(z), z=0,5), ratpoly); as my solution have     hypergeom([-1/2i, ....?

    for example where Qx = x/m, if m is also increasing from 0 to 5 by one in each term

    How to write these command?

    is it sum(Qx*z^m/m!, m=0..infinity); but convert this result to ratpoly result in error, if exp, it will have summation,

hi all,

To create an observability grammian I have to integrate a matrix with some equations that are difficult to integrate due to multiple time dependent variables. The simplest expression in the matrix is:

z₁^2 * sin( z₅ * t)^2          (1)

where z1 and z5 are from a state space model with 5 states and are given by:

z₁dot = z_{2     ...}

I am trying to use Tables to better organize the layout of my Document mode worksheets. I have noticed two problems thus far.1) When I use the triple exclamation point icon to execute the worksheet, sometimes the code in the Table is skipped. and 2) I put a simple plot command in one cell. The plot showed up in the cell, but the grapgh also showed up twice below the Table. If I only execute the code in the cell, this does not happen. There is no hidden code. If I...

hey,

i have a problem to get to the orthogonal point, but still there is a intersection and so should be as well a orthogonal point....

> S1 := proc (t) options operator, arrow; F[1](t)*m[1]*(1-F[2](t)) end proc;
> S2 := proc (t) options operator, arrow; F[2](t)*(m[2]+F[1](t)*m[1]) end proc;
> F[1] := proc (t) options operator, arrow; (1-exp(-(p[1]+q[1])*t))/(1+q[1]*exp(-(p[1]+q[1])*t)/p[1]) end proc;
> F[2] := proc (t) options operator, arrow; piecewise...

On the main page for the Rubi rule-based integrator, there is a table comparing results of Rubi against Maple and Mathematica.

On the face of it, the Maple results don't look so good. Maple is claimed as scoring about 82% correct on the author's example test suite. But only 42% of the suite gets an "optimal" result from Maple. The other 40% that Maple is claimed to get correct have results that are described as "Messy:

I am trying to solve a differential equations with the periodic coefficients, which have the following form:

where 

 ...

Is it possible to a plot,  shown in worksheet, insert vertical lines using the Builder plot ?

GRACIAS

Does anyone happen to have a worksheet that implements LinearAlgebra[Generic][SmithForm] 

for Euclidean domains like Z[w], w^3 = 1, or Z[sqrt(d)] where d = −11, −7, −3, −2, −1, 2, 3, 5, 6, 7, 11, 13, 17, 19, 21, 29, 33, 37, 41, 57, 73?

If so I would greatly appreciate receiving a copy of it.

--Edwin Clark

Good Morning.

I would like to know where Maple is statistics compared with other software. As a justification for the thesis i am doing. I found a page http://www.scientificweb.com/ncrunch/, but a report in 2008. I wish something more recent.

Thanks