I'm very new to this... I need to find the total derivative of y=(a-3)/(b+3) given that a=r*t and b=s*t

This is in a similar vein to the Diet problem (integer programming), but harder.

http://en.wikipedia.org/wiki/Cutting_stock_problem

This guy has solved this problem using 3 programs, Maxima and LPsolveIDE and Excel:

https://docs.google.com/View?docid=dfkkh8qj_64rrpz86db

A text file generated by maxima is fed into LPSolveIDE ...

Can someone please tell me where I can find information on "Test Relation" that pops up when I right click one of my equations?  Type ?test relation or into Help and nothing comes up.

Thanks!

Download Test_Relation.mw

How do I edit a large proc to replace a couple of lines or add a few more if I don't save it and the screen was cleared?  Am I out of luck and have to retype it all back in?

And how do I substitute in a proc n_pts<5 to n_pts<5  or say substitute i=50 to i=30 .  I'm stuck with the operators.  I thought using delayed evaluation would work.  ie/  newproc:=subs( 'i=5' = 'i=30' , eval(newproc))

How can I encode to mp3?  Maple's AudioTools package only includes WAV file formats.  I would think by now Maple 15 would have included the mp3 format seeing that it is so standard. 

None-the-less, I feebly started to embark on what I thought would be a quick two step process - 1 - find the mathematics involved and 2 - code in Maple.  My searches brought me to some good information at www.mp3-tech.org ...

int(cos(a*z)/(z^2-4*z+8), z, method=contour)

why run in maple 15, unknown options method = contour

is it default to use contour?

but the result is the same as done by hand, i mean the answer from the book,

int(cos(a*z)/(z^2-4*z+8), z) return contain some Si  and Ci

Pretty basic stuff here...

How can I get Maple to do this - go from Step (1) directly to Step (5 or beyond).  I'm guessing that all I have to do is figure out how to enter the derivative dy/dx into the document and then Solve for whatever variable I like.

Thanks in advance!

Can I make a jpeg file into the background of a plot?  

I want to make a topological map the background of the xy plane.

http://g.co/maps/4fznf

Thank you.

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...

This is a characteristic equation in which I am trying to locate roots for E of the following polynomial:

2*b^3-3*b^2*a+3*b^2*E-3*a^2*E+3*a*E^2-E^3+a^3

Any help would be greatly appreciated!

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!