Test_modify.mwGood Morning Everybody,

Can anybody demonstrate how I can convert the output from the procedure into an N X N Matrix depending on the nops from the attached file. Thanks everybody.

Regards,

Moses

with(LinearAlgebra):
a:=Vector([1,2]);
b:=Matrix([[1,2],[1,2]]);

Say if I need a^T * b * a, I will do this:

VectorMatrixMultiply(Transpose(a), b);
VectorMatrixMultiply(%, a);

But this seems too long for such a simple matrix （and vector) computation. I am sure there must be an short way.

What if I need more computation, like

a^T * b * c*d*f*g* a, where c,d,f,g are other 2x2 matrices.
 If I were to use the above command, that'll take a long time to input.

Thanks,

f:=x+y+y;

diff(f,x);
diff(f,y);
diff(f,z);

What I hope to get is a vector with i-th entry being the dervative of f, differentiated w.r.s.t the i-th parameter, like this

Vector([1,1,1]);

Is there a more efficient (built-in) command to do this?

VectorCalculus[diff] does not do what I want.

Thanks,

casper

Hi

I am using the Map function from the Threads package on a quad core processor, it only seems to use one thread however. The Array I am processing holds over 2 million entries and takes over 10 hours to calculate (single threaded).

Is this behavoir normal? I already tried to define a tasksize but that didn't work.

Kind regards

Jasper

Hi there

I have have a 18*18 matrix which almost each of its element are in symbolic form. Now I need to have all of its eigenvectors. Unfortunately when I use the "Eigenvalues()" function in maple i got nothing. In fact I got the error which comes below.

Error, (in content/polynom) general case of floats not handled

I need to know if there's a solution to eliminate the error? If not, what can I do to determine the eigenvectors and eigenvalues in symbolic form?

I'll be appreciated your help

Hi Maple friends.

I have a plot. I click on the plot, and the blue border appears the around the plot. I press the delete key on my keyboard, and the plot is not deleted. Not deleted when I press the backspace key either. I can right-click on the plot and choose 'cut', but that just copies the plot to the clipboard.

So how can I delete a plot from the worksheet, without deleting anything else?

Thanks in advance.

Hi Maple friends.

I am trying to differentiate these:

1. csc(x)/x

2. 3*x^2*cot(x)

From doing it by hand, I am getting:

1. -cosec(x)*(xcot(x) + 1)

2. 6x*cot(x) - 3x^2*cosec^2(x)

But Maple is giving the answer:

1. diff(csc(x)/x, x);

-csc(x)*cot(x)/x-csc(x)/x^2

2. diff(3*x^2*cot(x), x);

6*x*cot(x)+3*x^2*(-1-cot(x)^2)

My answers don't look like Maple's answers. Are they actually the same?

Thanks in advance.

The problem is how to plot a linear transformation, for example,

(x,y)->(x-y/2,y)

As, I searched, I found out that the code "LinearTransformPlot" can do that but it defines to act for example on lines or a certain subspace. May I ask you to learn the solution. Should we have a subspace untill we can plot the transformation? Thanks

Hello people in mapleprimes,

I want to modify the next equation: 

(**)  a:=sigma*omega*alpha = mu(H, H)*s*omega*gamma1*L+mu(F, H)*s*L-mu(F, H)*s*L*gamma1;

to be

(***)    sigma*omega*alpha = mu(H, H)*s*omega*gamma1*L+(1-gamma1)*mu(F, H)*s*L;

For that, first I defined b as

b:=sum(op(k,rhs(a)),k=2..3)=collect(sum(op(k,rhs(a)),k=2..3),{s,L,mu(F,H)});

, and substituted this to a with

subs(b,a);

But, what I could obtain was only the orignal equation (**) not (***).

Please tell me how to use subs to this problem to obtain (***)。

Thanks in advance.

taro

P.S.

I know

(****)collect(lhs(a)=rhs(a),{s,L,mu(F,H)});

works well as for what I wrote (**) as above.

But, originally, it was a result from substituting various equations into an equation.

For it, (****) does not work well.  

Whenever i open Maple 18, some symbols are missing including the arrows. I use Maple 18 to do math assingments, and the arrows are useful. It seems like a lot of other content is missing in Maple 18 as well. Below is a picture of the missing symbols, or there should be one. Any help on how i get the arrows back, would be amazing.

Hi, i'm trying to make a function to create 2 polygons with the same number of sides, the same center but different radius. These 2 polygons have to be on the same draw. I tried by doing this function but its not working..

 If anyone could help me it would be great and sorry for my bad english i'm from France.

Hallo

Use DrawSubgroupLattice for G:=Symm(4) then

A:=DerivedSeries(G);

Drawing this Series there are red marked 30,29,21,1.

But why not 8 or 9 or 10 which are between 21 and 1?

Best regards

Kurt Ewald

Hello! How can I find extremes of numeric solution of ODE system obtained using "dsolve"? Can I use something like "extrema" function?

Here is my code & the error mesage.  What's wrong?

with(Statistics);
X := Vector*([0, 5, 10, 15, 20, 25, 30], datatype = float);
Y := Vector*([38.8, 53.8, 82.4, 107.6, 130.7, 152.4, 173.2], datatype = float);
NonlinearFit(av^2+bv+c, X, Y, v);
Error, (in Statistics:-NonlinearFit) invalid input: PostProcessData expects its 1st argument, x, to be of type {array, list, rtable}, but received w

Hello,

How do I interpolate using polar coordinates?  I have a series with non-uniform spacing, that I want to map onto a uniform space polar grid.

Any assistance would be appreciated.