<p>sys := [diff(v(s, n), n)+diff(u(s, n), s)+diff(xi(s, n), s)+A*n*(diff(c(s), s)) = 0, A1*(diff(xi(s, n), n))+diff(v(s, n), s)-c(s)+A2*v(s, n)+A3*c(s) = 0, diff(u(s, n), s)+2*A2*u(s, n) = A2*(xi(s, n)+A*n*c(s))-A1*(diff(xi(s, n), s))-A2*n*c(s)] The dependent variables are v,u and xi and the boundary conditions are: bc := {u(0, n) = 0, v(s, -1) = 0, v(s, 1)} other things: -1<=n<=1. I tried ans := pdsolve(sys, bc, xi(s, n), u(s, n), v(s, n)) i also tried ans := pdsolve(sys, bc) I keep getting error messages about the dependent variables.

I have Maple 13 and am having trouble using multiple cores.... My CPU AMD Phenom x945 has 4 cores....

I generated some code in an attempt to use more than 1 core. However, CPU usage is only at 25%.

N := 6000
M := RandomMatrix(N, generator = -.1 .. .1, density = 0.5e-1)
P := RandomMatrix(N, generator = -.1 .. .1, density = 0.5e-1)
Q := MatrixMatrixMultiply(M, P)
MatrixInverse(Q)
A = M+P

CPU usage is only at 25% suggesting only 1 core is used.

In Maple's Help system there is an icon to switch the Examples from 1D Maple notation input to and from 2D Math input (the default).

Why is the 2D Math form of the Help Examples in red? That doesn't match the any of Maple's interfaces' entry modes, does it? Shouldn't the input be in black, to match what appears to be 2D Math input in Worksheet mode?

Also, the 2D Math form of the Help Examples loses inlined explanatory comments. For example, on the modp1 help there is this, in 1D Maple notation...

I am trying to solve these equations but I dont know how...

> sys := [diff(v(s, n), n)+diff(u(s, n), s)+diff(xi(s, n), s)+A*n*(diff(c(s), s)) = 0, A1*(diff(xi(s, n), n))+diff(v(s, n), s)-c(s)+A2*v(s, n)+A3*c(s) = 0, diff(u(s, n), s)+2*A2*u(s, n) = A2*(xi(s, n)+A*n*c(s))-A1*(diff(xi(s, n), s))-A2*n*c(s)];

 

print(`output redirected...`); # input placeholder

 

 

 Data:

My name is Darin Ohashi and I am a senior kernel developer at Maplesoft. For the last few years I have been focused on developing tools to enable parallel programming in Maple. My background is in Mathematics and Computer Science, with a focus on algorithm and data structure design and analysis. Much of my experience with parallel programming has been acquired while working at Maplesoft, and it has been a very interesting ride.

In Maple 13 we added the Task Programming Model, a high level parallel programming system. With the addition of this feature, and a few significant kernel optimizations, useful parallel programs can now be written in Maple. Although there are still limitations and lots more work to be done on our side, adventurous users may want to try writing parallel code for themselves.

To encourage those users, and to help make information about parallel programming more available, I have decided to write a series of blog posts here at Maple Primes. My hope is that I can help explain parallel programming in general terms, with a focus on the tools available in Maple 13. Along the way I may post links to sites, articles and blogs that discuss parallel programming issues, as well as related topics, such as GPU programming (CUDA, OpenCL, etc).

My next post, the first real one, I am going to explain why parallel programming has suddenly become such an important topic.

I was wondering how I can get the equation for Probability Density Function (PDF) for a variable x which follows

a normal distribution with mean 0 and stdev 10 but also has a stop at -10 (ie all x's that are more negative

than -10 becomes -10). I can plot such a function with the below code but I dont know

how to extract the equation for the PDF...humm

 

I'm trying to plot directly the result of a solve, using the following syntax:

plot(solve(diff(E,N)=0,N),Z=0..20);

( E is dependant of Z and N )
 

it works for an equation that has only 1 solution. But, when using an equation with two solutions, it only plot one of the solutions. Of course, it is always the solution I don't want.

I've tried solving this problem by forcing N to be above 0 ( the unwanted, but always plotted solution is negative ):

 

plot(solve({Ep-E=0,N>0},N),Z=0..20);

Dear experts, do you know how I can color and grid the surfaces/sides of the coordinate system when plotting a 3d plot?

Hello,

I am using the LinearAlgebra package, and I am dealing with very big square matrices (almost a hundred rows and columns).  They have a lot of eigenvalues, with high multiplicity.  

I am performing operations on the eigenspaces.  So what I would need is a matrix with as columns a basis with eigenvectors for a very specific eigenvalue.

I can of course use SubMatrix(Eigenvectors[2],....) but that would take ages and Eigenvectors gives the eigenvalues in an ever changing order.

Dear experts, I need to plot a scatterplot: I have a 3*1000 Matrix. Each line gives a x, y and z value of a certain point. Then I want to plot the 1000 point into a 3d scatterplot. Do you have an idea how I could proceed? Thanks a lot!

Hi all,

 

I just recently started using maple to supplement my math work. When I was just trying some random equations and graphing them, I tried to plot some 3D graphs. When I tried a simple equation, x+y from -2..2, I recieved this image. http://picasaweb.google.com/lh/photo/wnW4UIkdJck46smuTAnb4Q?feat=directlink

 

Recently I came across a page that was working with ifactor and it seems op now handles the operations a bit different now. 

ifactor(3^43+1);

       (2) (82064241848634269407)

a:=op(2,%):

ifactor(3^41+1);

       (2)(270547105429567)(33703)

b:=op(2,%):

c:=a*b;

     (82064241848634269407) (271547105429567)

I am using fsolve in maple 13 to find the crossing of a pair of implicitly defined functions in a triangular region.  I have been  using the startpoint option, but sometimes fsolve wanders out of bounds.  I have tried specifying the range as {x=0..1, y = 0..x}, but fsolve complains of an invalid range.  Any suggestions?

 

Thanks!

Michael

Maple experts,

(I am using Maple10)

I have the following system of equations, but I cannot obtain the solution. (I am able to solve by hand, but I want to verify and to solve the same sorte of equation but with more variables).

solve(    {z1s- p*y1s-(1-p)*y1=0, z2s- p*y2s-(1-p)*y2=0, z3s- p*y3s -(1-p)*y3= 0, y1s+y2s+y3s=1,   y1s-thetas1*(1- z1s-z2s) -(1-thetas1)*z1s=0 } , [y1s]);

What is my mistake?

Thanks in advance for the help.

Gabriel