Maple Questions and Posts

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Hi,

I'm very new to Maple and need some help.

I have a Matrix with the structure

M:= Matrix([[2013-08-13T00:29:24+0000,"text1"],[2013-08-14T00:29:24+0000,"text2"],[2013-08-15T00:29:24+0000,"text1"],[2013-08-16T00:29:24+0000,"text1"]])

 

and would like to plot this. Now problem one obviously is, it contains a timestamp. How can I use this in Maple? Second problem is, "text1" is a string, so I cannot use plotlist because it can not be converted to a float.

Hi all,

I am having some problems when solving high order polynomials. When oders are 'high' and systems involve multiple variables, Maple is slow to do so.

See in worksheet for detailed codes.

slow.zip

kappa - gives the vector that i am interested in

sC - a reparameterisation which has 'summation' in it

Aim is to verify that it works (it should!)

I currently ask...

I have the following pde system: sys[1] := [(D[1](u))(t, x)-(1/2*(x-x^2))*(D[2, 2](u))(t, x)-(-5.02*x+4.51+.1*x*(1-x))*(D[2](u))(t, x) = 0, u(t, 0) = 0.1e-1, u(t, 0) = 0.1e-1].

And have tried different bc's (some with derivatives at the boundary) but still get the same error: Error, (in simpl/Im) too many levels of recursion.

Could you please tell me where I am going astray?

Thank you.

Murray

If I have spreadsheet data, x and y (velocity and time), I need to find distance.  I see numbers of ways to do this, however, I wonder what people would suggest as the fastest / easiest way.  I'm not needing a function really, just results.  Does Maple have tools to simplyify this process, and if not, what process(s) might yield results of determinable or selectable accuracy.  I will have many sets of data in the future that need to be manipulated...

How can I draw following piecewise closed function t in  3-dimensional cartesian space

D124:=max(-x+y+z,x-y+z,x+y-z)=1; 
D134:=max(-x+y+z,x-y+z,-x-y-z)=1;
D123:=max(-x+y+z,x+y-z,-x-y-z)=1;
D234:=max(x+y-z,x-y+z,-x-y-z)=1;

 

t:=piecewise(x>0 and y>0 and z>0,D124,x<0 and y<0 and z>0,D134,x<0 and y>0 and z<0,D123,x>0 and y<0 and z<0,D234);

When defining a polynomial as follows

p:=x->x^(r+1)-(r+1)*Sum((-1)^(r+k)*(r+k)!*(r+1)!*r!/((k!)^2*(r-k+1)!*(2*r+1)!)*x^k,k=0..r);

the result of

simplify((eval(p(1),r=1)));

is given as 1 whereas hand evaluation and also plotting the polynomial clearly shows that the result is 0. How can this behaviour be explained?

Hi,

How do I get ride of these Rootof?

I tried simplify,evala,value,Simplify and ect. Didnt really find anything useful.

Download rootof.mw

 

I dont care which root they actually take, all I want is one of the roots. So I can then use subs for substitution.

Casper

How can I draw following piecewise closed function in  3-dimensional cartesian space

t:=piecewise(x>0 and y>0 and z>0,D124,x<0 and y<0 and z>0,D134,x<0 and y>0 and z<0,D123,x>0 and y<0 and z<0,D234); 

 


         max(-x + y + z, x - y + z, x + y - z) = 1 ,  0 < x and 0 < y and 0 < z
         max(-x - y - z, -x + y + z, x - y + z...

Hi,

 

Another (hopefully) simple question that I can't work out the answer for. How can I write an if loop for which n things must be true? I need to have:

if thing[1]=true and thing[2]=true and thing[3]=true and ... and thing[n]= true then
...;
fi; 

 

n will change for different inputs, so I can't write out explicitly.

Hope that makes sense! Thanks.

Good day.

Reading the documentation on Physics package in Maple, I did not find information about how Maple handle dummy indices of tensorial expressions. For example, suppose I have the following tensorial expression in Maple: 

    A[mu] * B[~mu] 

with dummy index mu. Then I want to apply the following simple substitution rule:

    A[alpha] = C[alpha]*C[mu]*C[~mu]  

Here, free index alpha should be...

I would like to plot the following expression that I call W

>W:=tau*exp(C4)/C1-exp(C4)*(exp(C3-C3*eta)/C3^2-exp(C3)/C3^2+tau/C1+eta/C3)+exp(C4-C3*eta/2)*Sum(16*beta[m]*sin(beta[m]*eta/2)*exp(-(beta[m]*beta[m]+C3^2)*tau/(4*C1))/((beta[m]*beta[m]+C3^2)*( beta[m]*beta[m]-C3^2)^2),m=1..n)

Where C1, C3, C4 are constant, and  beta[m]satisfies the relationship  

C3*sin (beta/2) =beta*cos (beta/2)

I want to plot the W-eta curve and W-tau curve (eta at [0, 1...

Dear sir i  want the contour values  automatically display on the contour.

Hear is the code and sample contour plot. 

contourplot(x^5-y^3,x=-5..5,y=-4..3,axes=boxed,contours=10);

Hi all,

What else could I try if I encounter this error?

Warning:  Incomplete separation.

--------------------------------

 

I read the pdsolve help page, where it says I should have a solution with this warning, but I got nothing but the error.

 

Dear Maple users

I am working on a problem, which basicly is dealing with putting n identical marbles in k different boxes. I need to run through all possible combinations and do something with it. The latter is unimportant. Mathematics say there are binomial(n+k-1,k-1) different combinations. I have already produced a recursive procedure to solve the problem and it is displayed below. I have placed a counter in the procedure to control if the procedures get through...

Hello,

I would like to assign a value I got from using the command 'Maximize'. What I gained as an answer is of the following form:
test:=[1234124, [t=124124124]] 

Now my point is to assign both these values to variables, which I can do for the first like:
first:= test[1];

But I just can't find out how to assign the second value.
I was trying it out by using the command 'rhs' but that doesn't work (although, not for me).

Probably a silly question, but yeah..thanks for a reply.

Frank 

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