I have a simple function as written below and I want to compute the partial derivative of it against an element u[k] in a vector variable u. I intentionally left k unspecified because it is not a set number and I don't really want to put it there to generate a bunch of specific output. But when I run it in Maple 12, it gives me the wrong result (sum((x-a[k])*(y-b[k]),k) instead of the correct result (x-a[k])*(y-b[k]).

restart;
with(PDEtools):
m:=(x,y,u)->sum(u[k]*(x-a[k])*(y-b[k]),k);
diff(m(x,y,u),u[k]);
 

Hi,

If anyone could help me out with these that would be great, thanks!

Consider this problem in differentiation:

d/dx [ sqrt(u^2) ],  where u is a differentiable function of x and u < > 0.

The answer is:

u'  (u/|u|),  where u' is the derivative of u with respect to x.

This problem involves implicit differentiation & the chain rule.

What Maple input will produce the answer above?

Alla

Hi folks, i'm ttrying to create an nxn array with n going as high as possibly 1000 to test the speed of a procedure i wrote.

Problem is, each row in the array has to have the numbers 1 to n arranged in a random order, with no number repeated.

Is there anyway to do this? Preferably using the Array command (think thats different from array...).

Cheers!

Hi,

Coul anyone help with this question?

Thanks

Your job is to test several forms of dampening coefficients to determine the ``best'' to use for safety
and comfort. You are to consider a modification of the harmonic motion differential equation
my"+ b(v) y'+ ky = 0

where m is the mass of the driver, k is the spring constant, and b(v) is the variable dampening coefficient.
For the first part of the problem, assume that m = k = 1. We will also be letting v = y' .

b(v)= v^4

Solve the ODE:

I have maple 12 and i am wondering how to approach a Newton's Method type problem. General help would be fine, but i m gonna supply a specific example that im interested in solving.

If anyone knows how to do this please respond as soon as possible, I am really having trouble with this

Does somebody have a sheet covering that algorithm for continous
anti-derivatives of rational functions (Bronstein's book §2.8
"Integration of transcendental functions")?

Or can show me, how to extract it from Maple's library in case
it is there (and I guess Maple covers that ...) for explicite
use?

Hello,

I am trying to change the variable in an integral and I have two problems with it:

My first problem is that I can't get the integrand of the new integral with GetIntegrand when I use IntegrationTools[Change] :

restart;

a1:=Int(1/(2*A),x=-A..A);

D1:=IntegrationTools[Change](a1,x=20*log[10](u));

I have used Maples' least squares capability to fit quadratic & cubic models without any problems.  However, the documentation includes this curious statement: "One can also specify nonlinear curves -- as long as the unknown parameters appear linearly."  What does this mean?  What would nonlinear parameters look like?
 

Alla

View 8939_simplify_CRRA.mw on MapleNet or Download 8939_simplify_CRRA.mw
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Dear all:

    I am wondering if there is any way in Maple you can do prettyprint with the printf?  Printf gives me more power but the output format of printf is "C-style". For example,

f := exp(x) + 3*sqrt(exp(x));

f1 := subs(exp(x)=y,f);

printf("Transformation is %a s.t %a => %a\n", f,f1 );

gives a display which is very hard to read. Is there any way to do a prettyprint with this kind of things?

Thanks,

Peter

Hi all,

I have a function defined as a sum:

with(PDEtools): mfx:=(x,y,ufx)->sum(ufx[k]*(x-x[k])*(y-y[k]),k);

I want to declare mfx(x,y,ufx) so that it would appear as mfx in subsequent displays. However, when I tried

declare(mfx(x,y,ufx));

Maple tells me that "Error, (in PDEtools:-declare) cannot declare objects as sum(ufx[k]*(x-x[k])*(y-y[k]), k)".

How can I solve this problem?

Thanks.