Hi folks, the package PDEtools has a nice command declare that allow us to display PDEs using jet notation: say f[x]-g[y] instead of diff(f(x,y),x)-diff(g(x,y),y) but when I try to export it to LaTeX or just trying to copy and paste the display in a text file, I always get the long expression. If I try to copy as MathML I got junk... Any ideas on how to copy an expression displayed in jet notation to a text document?

Voting is open for the next individual prize to be awarded as part of the Möbius App Challenge.  The winner will receive an iPad Prize Pack! 

Here are the finalist Apps:

• Parameterized Curves
• ODE Systems

Voting is open for the next individual prize to be awarded as part of the Möbius App Challenge.  The winner will receive an iPad Prize Pack! 

Here are the finalist Apps:

• Parameterized Curves
• ODE Systems

Hello, I would like to use the LeastSquares subpackage in the LinearAlgebra package in order to solve the following problem:

Set of data: (1.0,2.33),(2.0,0.0626),(3.0,-2.16),(4.0,-2.45),(5.0,-0.357),(6.0,2.21),(7.0,2.75),(8.0,0.636),(9.0,-2.45).

I am trying to put the above data in the curve y=a+b*cos(x)+c*sin(x)+d*cos(2x)+e*sin(2x).

My attempt to solve this:

restart;

with(LinearAlgebra);

Find the quadratic polynomial which interpolates (2,0), (6,1), (8,0). Start by setting f(x)=ax^2+bx+c, for example, and the unknowns as a,b,c.

eqt := y^5+y^4 + -0.5109*y^3 + -0.0595*y^2 + 0.0000-(-3.1086e-015*u^4 + u^3 + -0.5109*u^2 + -0.0595*u) = 0;

solve({eqt, y=m*t+c, u=n*t+d}, {y, u}, 'parametric');

solve({y^5+y^4 + -0.5109*y^3 + -0.0595*y^2 + 0.0000-(-3.1086e-015*u^4 + u^3 + -0.5109*u^2 + -0.0595*u) = 0, u=t}, [x,y]);

solve(eqt, [y(t), u(t)])

algcurves[parametrization](eqt, y, u, t);

all trials i failed

http://lib.freescienceengineering.org/search.php?search_type=magic&search_text=maple&submit=Dig+for

Bug in type(HFloat(-infinity),  pos_infinity). Negative infinity is incorrectly recognized as positive one:

s:=HFloat(-infinity);
                   HFloat(-infinity)

type(s, neg_infinity);
type(s, pos_infinity); # bug
                    ...

Hi. I have a question it goes.

Find the equation f(x) which satisfies the following conditions. f'(x)= 1/(1+cot(x)) and f(pi/4)=1.

So I enter the following in Maple and this is what I end up with.

http://s5.postimg.org/eriq99rs7/Maple.jpg

This should work as far as I can tell. The final diff command should return the original f'(x), but it doesn't. Can anyone tell me why?

I have used this exact method before on similair problems and it...

Hi,

I have a linear problem A*X = B, with dimensions of A approximately 500*1300, and B is a vector with only one nonzero coordinate.

I feed it to LinearSolve, and there are a *lot* of solutions - presented as one vector with linear polynomial coordinates.

How can I get only one (hopefully with as many zeros as possible) ?

Thank you in advance.

NoThik

Hi,

Does anyone know why I cannot solve the following system of equations?

solve({(-(0.1e-2+e+p)*j*(e*(-m+.68/d+.599/g)+j*m)/(((0.2e-2+0.1e-2)^2+(0.1e-2+e+p)*(0.1e-2+j+p))*i)+(0.2e-2+0.1e-2)*j*(j*(-n+0*(1/i)-.73/l)+e*n)/(((0.2e-2+0.1e-2)^2+(0.1e-2+e+p)*(0.1e-2+j+p))*i)-j*m/i)/(2*10) = -0.3e-2, (-(0.1e-2+e+p)*j*(e*(-m+.68/d+.599/g)+j*m)/(((0.2e-2+0.1e-2)^2+(0.1e-2+e+p)*(0.1e-2+j+p))*l)+(0.2e-2+0.1e-2)*j*(j*(-n+0*(1/i...

HI,

I have a system of ODEs like

Good morning sir,

In  general, there are five ways to decide the nature of a given square matrix based on the signs of the eigenvalues, for example

1. If the eigenvalues are positive then the nature is positive definite.
2. If the eigenvalues are negative then the nature is negative definite.
3. If the eigen values are nonnegative then the nature is Positive semidefinite.
4. If the eigenvalues are nonpositive then the nature is negative semi definite.
5. If the eigenvalues are positive and negative then the nature is indefinite.

triangle(T, [[x1,y1], [x2,y2], [x3,y3]]);

area:=proc(1/2*[x1(y2-y3)+x2(y3-y1)+x3(y1-y2)]);

AA:=(T)->[area(T)];

Hi, 

Struggling to get my head round how to plot the results of the follwoing, as it seems I have 4 variables...

I have a data file containing the results of the following problem:

1) Consider a cube. Each side (a,b,c) has a length of 1 unit.

2) Place an ion (0,0,0) where [a,b and c intersect] and find the associated energy at that point.

3) Move the ion to a point 0.05 units along side a to (0.05,0,0) and re-find the associated energy.