So I have the following:

restart;
with(Physics):
Setup(mathematicalnotation=true,coordinatesystems=cartesian);
Define(A[mu](X));

First of all X ist defined in terms of (x,y,z,t). Is is also possible to define it in terms of (t,x,y,z) with t being mu=0.

When I do

alias(X=(t,x,y,z))

this applies only to this one vector and

d_[4] is still the time differentiation, right?

Then I wanted to construct the divergence

d_[`~mu`] A[mu](X);
TensorArray(%,performsumoverrepeatedindices=true);

This should give me sth like d1 A1 + ... + d4 A4, but it stays with d_mu A_mu ?!?

Why?

Is there also a "function" which does the contraction?

So if I have

f[mu,nu]=d_[mu] A[nu](X)

eval(f[mu,nu],nu=mu)

contract(%)

??

evalf(Int(x*(1-2*x^(3/10))^(10./3),x=0..1));  # Crashes Maple

Note that:

int(x*(1-2*x^(3/10))^(10./3),x=0..1);
int(x*(1-2*x^(3/10))^(10/3),x=0..1);
are OK.

(Windows 7, Maple 2017.3, 64 bit)

Hi everyone,

I'm looking for some way to simplify the following procedure:

scm := proc(X, x) global xx;

if 1 <= X and X < 10 then xx := cat(x)

elif 10 <= X and X < 100 then if 1 <= x and x < 10 then xx := cat(0, x) else xx := cat(x) end if

elif 100 <= X and X < 1000 then if 1 <= x and x < 10 then xx := cat(0, 0, x) elif 10 <= x and x < 100 then xx := cat(0, x) else xx := cat(x) end if

elif 1000 <= X and X < 10000 then if 1 <= x and x < 10 then xx := cat(0, 0, 0, x) elif 10 <= x and x < 100 then xx := cat(0, 0, x) elif 100 <= x and x < 1000 then xx := cat(0, x) else xx := cat(x) end if

elif 10000 <= X and X < 100000 then if 1 <= x and x < 10 then xx := cat(0, 0, 0, 0, x) elif 10 <= x and x < 100 then xx := cat(0, 0, 0, x) elif 100 <= x and x < 1000 then xx := cat(0, 0, x) elif 1000 <= x and x < 10000 then xx := cat(0, x) else xx := cat(x) end if

end if

end proc

Any tips? Thank you in advance.

Hi 

I want to solve these equations in MAPLE, but something goes wrong. 

Download 11111111111111.mwWould you mind please check out my code11111111111111.mw

11111111111111.mw

Hello everyone,

I am experiencing a strange result. The Theta_double_dot got equated to zero in line 1.7. Please see the red arrow.

(I am using the Physics package)

How can I solve this issue?

u:=(x,t)->(40/Pi)*sum((1/r)*sin(r*Pi*x/2)*exp(-lambda^2*t),r=1....infinity);     r=1,3,5.... 

this is one dimensional heat equation solution. r values must be odd numbers and we can take the random r variable like 1000 .x=0...2 and t=0...1   but I don't know how can I draw 3d plot. If I write plot3d([u(x,t)],x=0...2,t=0...1); give an error.(bad range arguments)

Dear Maple useres,

I have a polynomial in the form f(s)/g(s) where f and g are polynomial of order 4 with coefficients in symbolic form. I want to convert it in a form of (s-a)*(s-b)*(s-c)*(s-d)/(s-a1)*(s-b1)*(s-c1)*(s-d1)

When i provide the numic value of  symbolic coefficients, Maple find it easy to factor it in the desired form. Otherwise i get a messy solution in the form of root of... expression. Even with assume command, I see no difference in the result. Is there a way to get the above simple form rather than root of expression?

thanks.

Hello!

I am currently working with the A = rosser Matrix. Which is found in Matlab. The task is to find the eigenvectors of this Matrix in Matlab and Maple. I have succeeded in matlab, but I am confused with Maple. What I have done:

1) In Matlab I save the A = roseer so I could import in from Maple

2) I go back to Maple

3) I write with(LinearAlgebra);

3) I use this path "Tools>Assistants>Import Data" and I select the saved Matlab file (Named A.mat) (No specific folder if that is important)

4) I use "Matrix Data Type" as "Anything" and I give the Variable name "A"

5) I now see the Matrix inside Maple. BUT I get dots after each value. Like this --> 99. 3. -147. etc - This might be an issue.

Note: I never get to select file format. Is that because they know it was a matlab file? Or a setting I am missing out on?

6) I write A := A[2] (According to teachers instructions)

7)  Then I write: eigenvects(A);  (Teachers isntructions)

But I am getting no proper values at all. I assume it is something with the import. So I added this 8x8 Matrix by hand. I got a better result with a result. But the result is wrong. I am getting 7 eigenvectors while there should be 8. See the code at: Method-two.mw

I am turning crazy over here. Anyone smart who could help me out please?

Hi,

I use Statistics[Biplot] and the rendering is very bad with those huge arrows.

For the moment I fix this by modifying the definitions of the curves which draw each arrow (after using getdata to recover the Biplot structure)

Does it exist a simpler way to manage the appearance of the arrows ?
(options cb, cw and ch of plottols[arrow] are incorrect in Statistics[Biplot](..., arrow=[...]).

Thanks in advance

Hello,

I used the interface(typesetting = extended) command to change the notation used for time derivative of o variable.

But it doesn't seem to be working well when the variable is in the supercript form (check the last line).

How can I solve this issue?

Mapleprimesquestion.mw

x/2 seems completely wrong as a CDF. In other cases Maple correctly writes the CDF as a piecewise-constant function clipped to 0..1:

with(Statistics):

dd := Distribution(ProbabilityFunction = 1/2, Support = 1 .. 2);

PDF(dd, x); # OK
                   (1/2)*Dirac(x-1)+(1/2)*Dirac(x-2)

CDF(dd, x);
                                (1/2)*x

Also CDF seems to have issues with DiscreteValueMap specified using a list, a table or piecewise():

dd := Distribution(ProbabilityFunction = 1/2, DiscreteValueMap = (n -> [1, 2][n]), Support = 1 .. 2);

PDF(dd, x); # OK
                    (1/2)*Dirac(x-1)+(1/2)*Dirac(x-2)

CDF(dd, x); # indeterminate
  int((1/2)*Dirac(0)*Dirac(_t-1)+(1/2)*Dirac(0)*Dirac(_t-2), _t = -infinity .. x)

with(Statistics):

CDF(Binomial(2, 1/2), x); # wrong
               piecewise(x < 0, 0, 2 <= x, 1, 1)

CDF(Binomial(2, p), x); # also wrong
     piecewise(x < 0, 0, 2 <= x, 1, p = 0, 1, p = 1, 0, 1)

Maple can actually generate PDFs for discrete distributions:

bpdf := unapply(PDF(Binomial(2, 1/2), x), x);
          x -> (1/4)*Dirac(x)+(1/2)*Dirac(x-1)+(1/4)*Dirac(x-2)

int(bpdf(t), t = -infinity .. x); # correct CDF
         (1/4)*Heaviside(x)+(1/2)*Heaviside(x-1)+(1/4)*Heaviside(x-2)

But then functions of random variables do not seem to work :

bdist := Distribution(PDF = bpdf, Support = -infinity .. infinity);

CDF(bdist, x); # OK
           piecewise(x < 0, 0, x = 0, undefined, x < 1, 1/4, x = 1, undefined, x < 2, 3/4, x = 2,
           undefined, 2 < x, 1)

CDF(add(RandomVariable(bdist), i = 1 .. 2), x); # indeterminate
          int((1/16)*Dirac(_t)^2+(1/4)*Dirac(0)*Dirac(_t-1)+(3/8)*Dirac(0)*Dirac(_t-2)+(1/4)*Dirac(0)*
          Dirac(_t-3)+(1/16)*Dirac(0)*Dirac(_t-4), _t = -infinity .. x)

It's a bit disappointing that Maple generates PDFs in terms of the delta function but doesn't support them properly, because that could be an easy and natural way to define mixed distributions.

There was a spam button that allowed a user with enough points to delete spam. It appears to have gone away, now we can just flag stuff as spam.

i have system of ode, which has three unkonwn function,x(t),y(t),z(t), and i need differentiation of theses function with respect to " t " , how can i use numeric solution to have these parameters? tnx for help in advance

 

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