Ok If R is the Cholesky decomposition of the Covariance matrix then I need:

i) Cov=R*R'
ii) R'=R

I can show that i) indeed holds but ii) does not seem to work. Why?

restart:
with(LinearAlgebra):
Cov := Matrix([[.1, .2], [.2, 1.3]]);
Ap := LUDecomposition(Cov, 'method' = 'Cholesky');

Cov = Ap.Transpose(Ap);
Ap = Transpose(Ap)

I am trying to solve differential equation, solve for y(t) if all initial conditions are zero. Use the Laplace transform.

d^2y/dt^2+12dy/dt+32y=32u(t)

Thanks in advance

In feedback control I want to isolate the fraction that defines my system: output/input.

This cannot directly be done by solve, isolate or simplify  in any of my attempts. What I've done is to follow the solutions for the following problem: http://www.mapleprimes.com/questions/37686-Isolating-Variable-Quotient

But my problem is apparently a little more hairy, since solving...

Hi everyone.

I have calculated three functions which led to three curves in a plot. Since I need to join them so as to create just one curve, I ask you if there's a method, even if approximated. I've thought about an interpolation but I don't know if it's feasible.

Thank you very much.

I am looking for a way to check if multiple variables are different. Let's say I have 4 variables named a, b, c and d. You can do it with "a!=b and a!=c and a!=d and b!=c and b!=d and c!=d", but it quickly becomes impractical when you have more variables.

Can anyone shed some light on this?

Thanks!

Good afternoon

i have problem with that program, because it's too slowly, i can't plot and i I have difficulty in keeping the processed data vector.

this program in matlab 12 seconds delay.

Thank you for your help

final-robot-circuloI.mw

Hey

I'm trying to solve this trigonometric equation:

e := 4·cos(t)+2·cos(2·t)=0. In the interval 0..2·Pi

However when i try: 

solve([e, 0 <= t <= 2 Pi], t, AllSolutions, explicit)

I won't give my a straight answer.

I have also given Student:-Calculus1:-Roots a try:

Student:-Calculus1:-Roots(e, t=0..2·Pi)

But it will only give me an answer when i use the numeric...

How to do this with Maple? Is it possible?

http://www.mapleprimes.com/ViewTemp.ashx?f=5794_1319135560/poissonHRI-1.jpg

Gracias

Hello, I'm trying to solve a very long system of equations, I've used PolynomialSystem and works, but it does not give me all of the solutions of the system. Im trying to do the solve comand, but after a few hours the mserver crasher and it needs to close, without having an output.

I woul really appreciate if anyone has a solution for this, I need to solve this and I'm getting stuck with this.

I'm attaching my worksheet  

Hi all,

 i have a problem with the equation generation in MapleSim, when using spring/damper elements in a Multibody-System. As an example, I've created a model of a mass-spring-damper system:

Hello everyone.

Now, I am studying nonlinear fitting method through help file of maple. Unfortunately, I'm not getting good fit using NonliearFit. The following is my psocedure:

> restart;
> with(Statistics);
> y := 1/(3.6+2.3*x)+17.6*exp(-0.2*x);
> fy := unapply(y, x);
> for x to 10 do fy(x) end do;
14.5791527795
11.9195840297
9.75432289049
7.98631476846
6.54090333018
5.35848939402
4.39086798669

Hi, I am very new to Maple and i was using Maple with a code that was running well when suddenly the rand() function that i use started to fail. and i get the error:

> rand();

Error, empty number

also i get many aditional errors in some sentences where i am addressed to some '?' simbols which are supposed to be in my sentendes.

has anyone gone trhough that? any help will be appreciated.

josep

I'm trying to do a least square estimation

with(plots);

q := array([892., 1012., 1060., 987., 680., 739., 809., 1275., 946., 874., 720., 1096.]);

p := array([1.23, 1.15, 1.10, 1.20, 1.35, 1.25, 1.28, .99, 1.22, 1.25, 1.30, 1.05])

lnx := array([seq([ln(p[t])], t = 1 .. 12)]);

lny := array([seq([ln(p[t])], t = 1 .. 12)]);

pointplot({seq([ln(p[t]), ln(q[t])], t = 1 .. 12)}, symbol = circle, axesfont = [TIMES, 14], labels = [x = ln(p), y = ln(q)])

Hi all! I have a list of data. I can use pointplot to plot them. Now, whatshould I do if I want to connect (join) these points toghether like an ellipse or rectangle or others form? For example:

S := [[1,1], [3,1], [4,2], [3,3], [2,3], [1,2]];

thanks  

Hi,

Can i use method=laplace to solve an ode with no initial condition?

ode := diff(phi2(x),`$`(x,2))-Omega0*diff(phi2(x),x)-k*R1*E1/C*sigma*phi2(x)-l^2*phi2(x)+2*R*k/C*N2*exp(Omega0*(x-1))*cosh(l*(x-1))*l*C2/exp(-l) = 0;

bcs:=phi2(1)=0,phi2(S0)=-N4*Phi;

sol := dsolve({ode, bcs}, phi2(x), method=laplace);

Thanks