Unanswered Questions

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

Hi all

trying to find analytically sin(erf(t)) and cos(erf (t)) rather than numerically

 

1/0;
Error, numeric exception: division by zero
lastexception;
            0, "numeric exception: division by zero"
lastexception; # ???
            Typesetting:-Typeset, "invalid input: %1 expects %2 arguments, but received %3", type, 2, 3

 

So, printing lastexception produces a new error!
When typesetting=standard, it's OK.

 

Hi, I have a procedure named f1. In it, it calls another procedure f couple of times. procedure f does not have recursive calls implemented.

I have no idea what caused the error. Could anyone give a hint?

Thanks a million in advance,

Best,

Jie

I like Maple the most for calculation of difficult parts. But when it comes to display, I am ignorant and do not know how to command the maple for showing me what is visible in the document.

I attach herewith my document which shows in print view only top half of the sketch. What should I do to show all three figures in the portrait page.
(Here below, after uploading it is shown alright, but in the print preview it is not showing!!).

I want to convert the doc to pdf. Therefore, in the doc preview itself it should be complete.

Thanks for help.

Ramakrishnan V
 

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``

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Download sketchesNotComing_in_full.mw

So, I am trying to write a method for array interpolation. I have a Matrix that is X by 3, where each column holds specific data (column 1 holds independent data 1, column 2 holds independent data 2, column 3 holds dependent data).

This data comes from a function with 2 independent variables, and I am creating a graph of this function, basically, with both independent variables going from 0 to 1 (approximately 300 values per variable, giving me a matrix with 90k values already). My goal is to use interpolation to get a lot of values in between the points I already calculated.

That being said, I don't know how to use the ArrayInterpolation command to achieve this. I will post my code below if anyone can help me out!

Code:

Interpolate := proc(M::Matrix)
  local i; local j;
  local M1 := Matrix(RowDimension(M),1);
  local M2 := Matrix(RowDimension(M),1);
  local M3 := Matrix(RowDimension(M),1);
  for i from 1 to RowDimension(M) do
    M1(i) := M(i,1);
    M2(i) := M(i,2);
    M3(i) := M(i,3);
  end do;
  print(M1,M2,M3);
  local M4 := Matrix(1000,1);
  local M5 := Matrix(1000,1);
  for j from 1 to 1000 do
    M4(j,1) := 0.001*j;
    M5(j,1) := 0.001*j;
  end do;
  ArrayInterpolation([M1,M2],M3,[M4,M5]);
end proc;

How I can replace  u__0r, theta, t) with f1, 1(r, theta) in attached file.

I want in I have only f1,1] function.

Thanks 


 

````

"f[1, 1](r, theta):=`u__0`(r, theta,t)  "

proc (r, theta) options operator, arrow, function_assign; u__0(r, theta, t) end proc

(1)
``````````

"L[1, 1](r, theta):=-`A__0`*(∂)/(∂r) (F*(∂)/(∂r)`u__0`(r,theta))-1/(2)*`A__0`*(∂)/(∂r) (`K__1`*`u__0`(r,theta))+1/(2)*`A__0`*`K__1`*(∂)/(∂r)`u__0`(r,theta)-1/(2)*`A__0`*(∂)/(∂ r) (`H__1`*`u__0`(r,theta))+1/(2)*`A__0`*`H__1`*(∂)/(∂r)`u__0`(r,theta)+`K__3`*`A__0`*`u__0`(r,theta)-1/(2)*`A__0`*(∂)/(∂ r) (`K__4`*`u__0`(r,theta))+1/(2)*`A__0`*`K__4`*(∂)/(∂r)`u__0`(r,theta)+`A__0`*`K__5`*`u__0`(r,theta)-2*`A__0`*(∂)/(∂ theta) ((`H__2`)/(r)*(∂)/(∂theta)`u__0`(r,theta))+(1)/(4)*`A__0`*l^(2)*((∂)^(2))/(∂ r ∂ theta)(mu*((∂)^(2))/(∂r ∂theta)`u__0`(r,theta))+(1)/(4)*`A__0`*l^(2)*((∂)^(2))/(∂theta^(2))(mu*((∂)^(2))/(∂ theta^(2))`u__0`(r,theta))+rho*`A__0`*`K__16`*((∂)^(2))/(∂t^(2))`u__0`(r,theta);"

proc (r, theta) options operator, arrow, function_assign; -A__0*(diff(F*(diff(u__0(r, theta), r)), r))-(1/2)*A__0*(diff(K__1*u__0(r, theta), r))+(1/2)*A__0*K__1*(diff(u__0(r, theta), r))-(1/2)*A__0*(diff(H__1*u__0(r, theta), r))+(1/2)*A__0*H__1*(diff(u__0(r, theta), r))+K__3*A__0*u__0(r, theta)-(1/2)*A__0*(diff(K__4*u__0(r, theta), r))+(1/2)*A__0*K__4*(diff(u__0(r, theta), r))+A__0*K__5*u__0(r, theta)-2*A__0*(diff(H__2*(diff(u__0(r, theta), theta))/r, theta))+(1/4)*A__0*l^2*(diff(mu*(diff(u__0(r, theta), r, theta)), r, theta))+(1/4)*A__0*l^2*(diff(mu*(diff(u__0(r, theta), theta, theta)), theta, theta))+rho*A__0*K__16*(diff(u__0(r, theta), t, t)) end proc

(2)

``


 

Download replace

 

Hi, my codes ran smoothly well until I changed some assignment value. It reported invalid object error.

Error, Got internal error in Typesetting:-Parse:-Postprocess : "internal error: invalid object "

Part of the codes are as follows:

""sigma:=0.00002:    m:=5:   n:=4:
Error, Got internal error in Typesetting:-Parse:-Postprocess : "internal error: invalid object "

Could anyone give some hints on what goes wrong here? It seems to be a configuration issue but I completely have no clue..

Thanks a million in advance,

Best,

Jie

 

 

How 2 solve summation when M,  Z,  X are given with mixed conditions?

restart;

##########  omega and theta are variables,where J[3],F[2],H[2],etc are constants.

#### I tried with "evlf" and "evlc" command but maple was not ready to provide the solution,please help me to solve this

t1:=-1/(-16.*omega^2+exp(-4*omega)+exp(4*omega)-2.)*(-(0.5817764173e-1*I)*exp((2/9)*omega*cos(theta))*omega^5*cos(theta)*J[3]-(.6981317009*I)*exp((2/9)*omega*cos(theta))*omega^4*cos(theta)*H[3]-0.4524927691e-1*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^3*G[3]-.6205615118*exp(.1111111111*omega*(2.*cos(theta)-9.))*cos(theta)*omega^3*H[2]+.6205615118*exp(.1111111111*omega*(2.*cos(theta)-9.))*cos(theta)*omega^3*F[2]+.9308422676*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^4*H[3]-.1034269187*exp(.1111111111*omega*(2.*cos(theta)-9.))*cos(theta)*omega^3*G[2]-0.7757018900e-1*exp(.1111111111*omega*(2.*cos(theta)-9.))*cos(theta)*omega^2*G[2]-0.7757018898e-1*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^4*J[3]-0.9696273622e-1*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^3*J[3]-0.4524927691e-1*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^2*J[3]-.2714956613*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^2*H[3]-0.7757018898e-1*exp(.2222222222*omega*(cos(theta)-9.))*cos(theta)*omega^4*G[3]+0.8726646261e-1*exp((2/9)*omega*cos(theta))*omega^3*J[3])*cos((2/9)*omega*sin(theta));

t2:=int(int(t1,omega=0..infinity),theta=0..2*Pi);

 

 

Problem copying a document to Maple Cloud (Public domain)

• Reset password

• Verified email is correct

• Chose File → Save to Cloud... (or clicked Send Document to Cloud on Maple Cloud palette) either way opend Login dialog

• Entered  Account = Maplesoft account, my Email and password then clicked Log in.  The following message appears: "The account type or email address or password is incorrect"

I've saved .mw files to Maple Cloud before with no problems.  Any help appreciated.

Thanks, Les

I have the equation (𝑑π‘₯/𝑑𝑑)^2=π‘Žπ‘₯^3+𝑏π‘₯^2+𝑐π‘₯+𝑑.

How do I plot π‘‘π‘₯/𝑑𝑑 against x? (as the coefficients a, b, c and d vary)

I expect it looks like the following graph:

Thank you for your help.

Hello,

I'm confused about Maple's adjoint function (in the DEtools package). When I take the adjoint of the derivative operator:

DEtools:-adjoint(Dx, [Dx, x])

 

I get back simply "Dx". However, doing the calculation by hand and integrating by parts seems to indicate that this should return the negative of Dx. The inner product I'm using is int(f(x)*conjugate(g(x)), x=0..1). Is Maple perhaps using a different inner product? Or is this a generalization that I'm unaware of? Or is it perhaps just a bug?

 

Thanks!

Consider a wave y=f(x,t) with amplitude modulation such that it becomes

 y_new=(1+A)*f(x,t), where A=A(t) is a small perturbation.

How can I do the simulation to test the robustness of the system to see if the wave is stable / unstable under perturbation? As the time t goes to infinity, I want to see if the original wave is distorted or not under either random or prescribed perturbation.

P.S. For example,  f(x,t) = (sech(0.5*x-0.1*t))^2.

Thank you for your help.

Hi I have encounted this error:

Error, (in diffalg/DAparse_polynomial) unknown indeterminate or coefficient outside base field, -Cp+Cf/(1+Kw*(-sigma*`ΔPi`+`ΔP`)*(1-(1/2)*Fp/Ff)/Ks)

The text highlighted in bold is an equation that I typed in.

 

Can I know what it means?

1,1,2,2,2,3,3,2,2,1,2,2,2,3,3,1,1

i would like to research the ordering mechanism of this kind of series Before sorting.

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