Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Dear,

I have a perfectly working when all parameters are known (figure 1), however I want to perform a sensitivity analysis by derivating the code if one parameter is unknown. Because of multiple possible answers and because of the complexity of the formula, I cannot run this script and get solutions. Any ideas how I can this calculation lighter so it is able to run? Values should be real and positive (so 1 or 2 solutions are the only one I'm interested in)

Any ideas, how I can make this code runnable? (file is below)

I'm stuck on this for a while now :/ So I hope someone will be able to help me

Many thanks in advance!l

Question.mw

Figure 1: [URL=http://s1240.photobucket.com/user/laggstar/media/Parameter%20f%20known.png.html][IMG]http://i1240.photobucket.com/albums/gg494/laggstar/Parameter%20f%20known.png[/IMG][/URL]

 

Figure 2: [URL=http://s1240.photobucket.com/user/laggstar/media/Parameter%20f%20unknown.png.html][IMG]http://i1240.photobucket.com/albums/gg494/laggstar/Parameter%20f%20unknown.png[/IMG][/URL]

This should be trivial but I am not able to figure out the right syntax to execute it

The pdf is given by :

f_X(x)={ 1/25 *x, 0<=x<5

             2/5 -x/25, 5<=x<10

             0, otherwise

I have tried to use the "CumulativeDistributiveFunction" so far

Hi!

 

I am trying to solve a large nxl system of coupled differential equations. Maple seems to have trouble even for small n's so I wanted to know if anyone has any suggestions. Take the case of the following system of ODEs for my unknown functions f[0,0](x) and f[1,0](x). 

 

ODEs:= {diff(f[0, 0](x), x)+2.*f[0, 0](x)/x^5+.5000000000*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+140.2961154*sin(.5773502693*x)/x^4-81.*cos(.5773502693*x)/x^3, diff(f[1, 0](x), x)+6.*f[1, 0](x)/x^5+1.500000000*f[1, 0](x)/x-1.*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+25.98076212*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^2+140.2961154*sin(.5773502693*x)/x^4-233.8268591*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^4-81.*cos(.5773502693*x)/x^3+135.*cos(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^3-20.78460970*sin(.5773502693*x)/x^6+6.000000004*cos(.5773502693*x)/x^5+62.35382908*sin(.5773502693*x)/x^8-36.00000002*cos(.5773502693*x)/x^7, f[0, 0](.1) = 1.503497680, f[1, 0](.1) = -.5011660086}

 

 

Following Preben Alsholm's suggestion from my previous thread I am using lsode[adamsfull], since no other method i have tried worked for this problem. I am currently using:

 

Sollsodefull:=dsolve({ODEs}, numeric, method = lsode[adamsfull])

 

and it seems to work. I am wondering if there is a way to optimize this, as I will be extending my problem to n and l much larger than order unity numbers, therefore my system will contain about 10^4-10^5 equations. Solving this symple system of 2 equations takes a bit less than a second, but still it takes some time for the processor on my MBP. I am affraid it will be a nightmare for the full problem. Whats the most optimal dsolve option for this kind of problem? Any ideas?

 

I have also attempted dverk78, rkf45,rosenbrock, lsode(without the adamsfull option), and all failed for this particular system. Errors were:

1. For rkf45: Error, (in f00) cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up

2. For dverk78: Error, (in Soldverk78) cannot evaluate the solution past .1, step size < hmin, problem may be singular or error tolerance may be too small

3. For rosenbrock: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

4. For lsode without [adamsfull]: Error, (in Sollsode) an excessive amount of work (greater than mxstep) was done

5. For default method with stiff=true and inplicit=true options: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

Dear all,

I want to use the Maple Compiler to improve the performance of some of my codes. To get used to it, I tried doing the examples from the ?Compiler help-page, but everytime I run the compiler, I get the error message:

"Error, (in Compiler:-Compile) compiler exited with nonzero status 1: 

Do some of you know a possible reason for this?

Thank you all.

Download test.mw


Hi
Please give me the matlab coding for plot together of attach figure by matlab.fig
thanks...!

Hello, 

is there a way I can use data (variables) from Maple environment in the Maplesim environment. 

I have a scirpt in maple that generates the robots joints angles and need to use them in the 3D robot built in maplesim. I know I can export/Import data, but this sounds redundant. Is there a way to simply use an input block as a source of the data in maplesim and have the variable name generated in maple used int. Similar to what Matlab/Simulink does.. 

 

 

thanks.

Могу ли я использовать Клен, чтобы найти конкретные решения, которые выражаются либо в начальных и эллиптических функций для систем обыкновенных дифференциальных уравнений. Например, вы можете получить в Maple решений (sub_Solve01, sub_Solve02) для систем, которые перечислены в файле?
exp01.mw

I have a system of pdes and solved numerically using pdsolve (numeric) command.

The system consists of four first order partial differentia equations.

for example u(x,t), R(x,t)....

what command should I give to the Maple and get the graph of u(x,t) at a specific point x_0?

For example, I need a plot for u(30,t).

Is it possible with the maple plot?

I really appreciate your help.

Thank you for reading this post. :)

 

So this is my minimal working code. Everything works, but I cannot get the arrow size fixed you can see the animation propperly. Adding wid=1/2 gives an error message.

Hi,

Is there a way to export worksheet to pdf format but not in A4 size since some lines are going beyond the page?


restart; with(Physics); with(Tetrads); with(PDETools)

0, "%1 is not a command in the %2 package", Tetrads, Physics

(1)

coords := zetabar, zeta, v, u

zetabar, zeta, v, u

(2)

X = [coords]

X = [zetabar, zeta, v, u]

(3)

ds2 := Physics:-`*`(Physics:-`*`(2, dzeta), dzetabar)+Physics:-`*`(Physics:-`*`(2, du), dv)+Physics:-`*`(Physics:-`*`(2, H(coords)), Physics:-`^`(du+Physics:-`*`(Ybar(coords), dzeta)+Physics:-`*`(Y(coords), dzetabar)-Physics:-`*`(Physics:-`*`(Y(coords), Ybar(coords)), dv), 2))

2*dzeta*dzetabar+2*du*dv+2*H(zetabar, zeta, v, u)*(du+Ybar(zetabar, zeta, v, u)*dzeta+Y(zetabar, zeta, v, u)*dzetabar-Y(zetabar, zeta, v, u)*Ybar(zetabar, zeta, v, u)*dv)^2

(4)

PDEtools:-declare(ds2)

Ybar(zetabar, zeta, v, u)*`will now be displayed as`*Ybar

(5)

vierbien := Matrix([[1, 0, -Ybar(coords), 0], [0, 1, -Y(coords), 0], [Physics:-`*`(H(coords), Y(coords)), Physics:-`*`(H(coords), Ybar(coords)), 1-Physics:-`*`(Physics:-`*`(H(coords), Y(coords)), Ybar(coords)), H(coords)], [Y(coords), Ybar(coords), -Physics:-`*`(Y(coords), Ybar(coords)), 1]])

vierbien := Matrix(4, 4, {(1, 1) = 1, (1, 2) = 0, (1, 3) = -Ybar(zetabar, Zeta, v, u), (1, 4) = 0, (2, 1) = 0, (2, 2) = 1, (2, 3) = -Y(zetabar, Zeta, v, u), (2, 4) = 0, (3, 1) = H(zetabar, Zeta, v, u)*Y(zetabar, Zeta, v, u), (3, 2) = H(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (3, 3) = 1-H(zetabar, Zeta, v, u)*Y(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (3, 4) = H(zetabar, Zeta, v, u), (4, 1) = Y(zetabar, Zeta, v, u), (4, 2) = Ybar(zetabar, Zeta, v, u), (4, 3) = -Y(zetabar, Zeta, v, u)*Ybar(zetabar, Zeta, v, u), (4, 4) = 1})

(6)

``

Physics:-Setup(coordinatesystem = (X = [zetabar, zeta, v, u]), metric = ds2, tetrad = vierbien, mathematicalnotation = true, automaticsimplification = true, signature = "+++-")

RicciT := proc (a, b) options operator, arrow; Physics:-SumOverRepeatedIndices(Ricci[mu, nu]*e_[a, `~mu`]*e_[b, `~nu`]) end proc

proc (a, b) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-`*`(Physics:-`*`(Physics:-Ricci[mu, nu], Physics:-Tetrads:-e_[a, `~mu`]), Physics:-Tetrads:-e_[b, `~nu`])) end proc

(7)

SlashD := proc (f, a) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-D_[mu](f)*e_[a, `~mu`]) end proc

proc (f, a) options operator, arrow; Physics:-SumOverRepeatedIndices(Physics:-`*`(Physics:-D_[mu](f), Physics:-Tetrads:-e_[a, `~mu`])) end proc

(8)

SlashD(H(X), 4) = H(X)[4]

(diff(H(X), zetabar))*Ybar(X)+(diff(H(X), zeta))*Y(X)+diff(H(X), v)-(diff(H(X), u))*Y(X)*Ybar(X) = H(X)[4]

(9)

Gamma := proc (a, b, c) options operator, arrow; -gamma_[a, b, c] end proc

proc (a, b, c) options operator, arrow; Physics:-`*`(Physics:-Tetrads:-gamma_[a, b, c], -1) end proc

(10)

Gamma(1, 4, 4) = 0

-(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0

(11)

``

Gamma(2, 4, 4) = 0

-(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0

(12)

``

Gamma(3, 4, 4) = 0

0 = 0

(13)

``

Gamma(4, 4, 4) = 0

0 = 0

(14)

Gamma(4, 1, 1) = 0

-(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0

(15)

``

Gamma(4, 2, 2) = 0

-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0

(16)

NULL

shearconditions := {-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0, -(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0, -(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0, -(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0}

{-(diff(Y(X), zetabar))+(diff(Y(X), u))*Y(X) = 0, -(diff(Ybar(X), zeta))+(diff(Ybar(X), u))*Ybar(X) = 0, -(diff(Y(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Y(X), zeta))+(diff(Y(X), zetabar))*Ybar(X)+diff(Y(X), v) = 0, -(diff(Ybar(X), u))*Y(X)*Ybar(X)+Y(X)*(diff(Ybar(X), zeta))+Ybar(X)*(diff(Ybar(X), zetabar))+diff(Ybar(X), v) = 0}

(17)

simplify(RicciT(1, 2), shearconditions) = 0

H(X)*(diff(diff(Y(X), zeta), zetabar))*Ybar(X)-H(X)*Ybar(X)*Y(X)*(diff(diff(Ybar(X), u), zetabar))-H(X)*Ybar(X)^2*(diff(diff(Y(X), u), zetabar))-H(X)*Y(X)^2*(diff(diff(Ybar(X), u), zeta))-2*H(X)*Y(X)*Ybar(X)*(diff(diff(Y(X), u), zeta))+H(X)*Y(X)^2*Ybar(X)*(diff(diff(Ybar(X), u), u))-H(X)*Y(X)*(diff(diff(Ybar(X), u), v))+H(X)*Y(X)*Ybar(X)^2*(diff(diff(Y(X), u), u))-H(X)*(diff(diff(Y(X), u), v))*Ybar(X)+H(X)*(diff(Ybar(X), zetabar))^2+(-3*H(X)*Y(X)*(diff(Ybar(X), u))-(diff(H(X), u))*Y(X)*Ybar(X)+(diff(H(X), zeta))*Y(X)+(diff(H(X), zetabar))*Ybar(X)+diff(H(X), v))*(diff(Ybar(X), zetabar))+H(X)*(diff(Y(X), zeta))^2+(-4*H(X)*(diff(Y(X), u))*Ybar(X)-(diff(H(X), u))*Y(X)*Ybar(X)+(diff(H(X), zeta))*Y(X)+(diff(H(X), zetabar))*Ybar(X)+diff(H(X), v))*(diff(Y(X), zeta))+2*H(X)*Y(X)^2*(diff(Ybar(X), u))^2-Y(X)*((diff(H(X), zetabar))*Ybar(X)+(diff(H(X), zeta))*Y(X)+diff(H(X), v)-(diff(H(X), u))*Y(X)*Ybar(X))*(diff(Ybar(X), u))+2*(H(X)*(diff(Y(X), u))*Ybar(X)+(1/2)*(diff(H(X), u))*Y(X)*Ybar(X)-(1/2)*(diff(H(X), zeta))*Y(X)-(1/2)*(diff(H(X), zetabar))*Ybar(X)-(1/2)*(diff(H(X), v)))*(diff(Y(X), u))*Ybar(X) = 0

(18)

0 = 0

0 = 0

(19)

The values in the paraenthesis  should substitute H[4]. This sequence works in Maple 18 but not in Maple 2015

 

NULL


Download Question_algsubs_3.27.15.mw

Write a Maple code that performs the Gaussian elimination for an nxn matrix, converting it to an upper triangular matrix. 

(Hint: you will need to use three for .. do loops.)

I want to make the model which moves along the specific direction (translational), So I used the "prismatic joint" to give the direction that I want to enforce. However, "Prismatic joint" only offers the direction along the "X", "Y", and "Z" axes though I want to give other direction.

 

Is there any way to give the specific direction (vector) to make my model move in that way ?

hello

i have some problem when iuse the digital libray with the delay components:

i have this error: delay variable not found in dependent variable list, [`Main.TransportDelay1.x`(T)]

it seems that the delay function in the modelica language is not well treated in MapleSim . At this level:

 

equation
    y = if 0 < delayTime then if delayTime <= time then x_delayed else y0 else pre(x);
    x_delayed = integer(delay(x, delayTime));
end Modelica.Electrical.Digital.Delay.TransportDelay;

 

Thank you for your help.

 

 
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