MaplePrimes Questions

Hi everyone,

I have a strange problem with the LSSolve function. I get an error when specifying an optimality tolerance as an option for LSSolve function : "unexpected parameters: optimalitytolerance = 1/1000" (see attached). When I remove the option, the LSSolve function works and returns something. Why ?

This is a problem for me because in my program I automatically generate lots of equations and I need to solve them using the same parameters.  "list1" is an example of a list that makes LSSolve to return an error and therefore it makes my program stop.
Is it possible, when LSSolve returns an Error, to re-run the function without the optimalitytolerance option ?
 

with(Optimization):

[0.127345646906885e-1-0.186555124779203e-2*D32-0.282637107183903e-3*D33, -0.427981372479296e-2+0.184372031092059e-1*D32+0.366060535331614e-2*D33, -0.279056870350439e-1+0.497068050546578e-1*D32+0.300683751452398e-1*D33, -0.159123153512316e-1-0.200310190531632e-2*D32+0.110642730744851e-1*D33, -0.358677392345135e-2-0.477282036776905e-2*D32+0.279495051520868e-2*D33, -.158025406913808+.301050727553470*D32+0.991309483578555e-1*D33, -0.767170565747362e-1+0.287589092672543e-1*D32+0.380554240544922e-1*D33, 0.134025593814442e-1-0.163134747085529e-1*D32-0.978424817965354e-2*D33, 0.177936771272063e-1-0.193555892719151e-1*D32-0.117324484775754e-1*D33, .136323651819599-.101383912457110*D32-0.800923073293239e-1*D33, 0.658540765374620e-1-.134530865070270*D32-0.449966493124888e-1*D33, 0.366589441985546e-1-0.923517762126252e-1*D32-0.313964041159186e-1*D33, 0.200320004853408e-2-0.454710553314498e-2*D32-0.121523285055995e-2*D33, 0.362766049610844e-2-0.103494064252009e-1*D32-0.347855768021822e-2*D33, 0.431461474510905e-2-0.122762710681104e-1*D32+0.305664301894285e-3*D33]

(1)

LSSolve(list1, [0 <= D32, 0 <= D33], optimalitytolerance = 10^(-3))

Error, (in Optimization:-LSSolve) unexpected parameters: optimalitytolerance = 1/1000

 

``

``

 

 

worksheet_help.mw



Thanks in advance,
Lilian

Dear all,

I am making a plot, which is Delta z/Delta t vs. z.

but in labeling maple prints z/t, because it simplifies Delta  !

You can find my worksheet below.

Could any of you help me with this please?

Thanks in advance!

DzDt := z^2; -1; plot(DzDt, z = 0 .. 4, labels = [z, typeset(Delta*z*(1/(Delta*t)))])

 

``

 

 

 

I'm defining forces. The only thing I changed is x to y for one particular piece of an equation. I copied and pasted it so I don't see why it's not working.

opparam_fail.mw

hi!

Hi I have a 8x8  matrix and I was attempting to get maple to find the eigenvalues. but after a while I thought it is caught in an infinite loop!  anyway I manually kill the mserver processing and saved the maple worksheet and restarted the laptop. but after all these it seems its still working.CPU usage and memory (in task maneger) are still high! 

how can I get rid of this condition?

 

In the Maple help to use a matrix defined monomial order it is said to define a matrix and a list of variables and then typing 'matrix'(M,V). But I fail to use it. A very simple example:

M:=<<1,0>|<0,1>>;
V:=[x,y];
Groebner[LeadingMonomial](y^3+x*y, 'matrix'(M, V));

But Maple shows this error:

 

Error, invalid input: Groebner:-LeadingMonomial expects its 2nd argument, tord, to be of type {MonomialOrder, ShortMonomialOrder}, but received matrix(Matrix(2, 2, {(1, 1) = 1, (1, 2) = 0, (2, 1) = 0, (2, 2) = 1}), [x, y])

What is wrong?


 

Download example.mw

I tried to solve some linear differential equations,

but the result is incomplete.

The complete solutions have been derived by hand.

How can I get the right result using maple?

The example is from determining symmetres of differential equations.

Thank you!

 

How to solve this problem? I want to display plot of differential equation system

this download link my problem https://drive.google.com/file/d/0B-qKE-5zgVbLeWVMd0xkMFY1Y00/view?usp=sharing

Thank you :)

  1. I have a set of equations described on different lines and I want them to be executed together and their answers to be displayed in seperate lines after that. How do I do that?
  2. This is particulalry important because, at times I will have to document multiple equations sequentially and later on have their answers reffere to. This way its more structured and I can group equations falling into certain category.

Please find the attached Minimum working example. Any advise is appreciated. File link: [MWE.mw]

 

Thanks

 

 

Hello,

i look for an Maple animation about similar triangles? Thank you

HI MaplePrimes,

The input -

rsolve(f(n)=f(n-1)+10*f(n-2),f(k))

returns a large expression.

My had calculations reduce this to

f(k) = [(41-19*sqrt(41))/820]*[((1-sqrt(41))/2)^k+((1+sqrt(41))/2)^k)].

There may be an error.

We let f(1)=1 and f(2)=2.

The sequence, starting with 1 should read -

1,2,12,32,152,472,...

What is the correct expression for f(k)?

 

Regards,

Matt

Consider a standard initial/boundary value problem for the heat equation on the interval x ∈ [0,1]:

restart;
pde := diff(u(x,t),t) = diff(u(x,t),x,x);
ic := u(x,0) = f(x);
bc := u(0,t)=0,  u(1,t)=0;

Then
pdsolve({pde, ic, bc});
produces the expected Fourier series solution.

However, if we change the interval to x ∈ [-1,1], as in:
bc := u(-1,t)=0,  u(1,t)=0;
pdsolve({pde, ic, bc});

then Maple fails to return a solution.  Why?

Dear all

I need a help how can i solve for example the following PDEs with Initial condition and boundary condition given at x=-1, and x=1.

pde:=diff(u(t,x),t)=diff(u(t,x),x$2);

ics:=u(0,x)=sin(x);

Bcs:=diff(u(t,-1),x)=0;

Bcs:=diff(u(t,1),x)=0;

Many thanks

 

 

 

In using Isolate in RootFinding to compute roots of a real polynomial, the output contains, say, z= some number.  How to get rid of the "z =" so that I can declare that "some number" to be some variable?

I am writing a matrix to file where each matrix element is placed on a new line. An example of such code:

restart:
HH:=Matrix([[x**2,x**z,z**12],[2*x,5**y,6**1]]):
filenameHH:=fopen("test.txt",WRITE,TEXT):

nRow,nCol :=LinearAlgebra[Dimension](HH);
for i from 1 to nRow do
   for j from 1 to nCol do
      fprintf(filenameHH,"%a\n",HH[i,j]):
   od:
od:
fclose(filenameHH):

When this is printed to file, it will print as the power sign ^ regardless of the input it is given. This particular output file will be read in by another language, and due to this the power symbol "^" is not desired, but instead " ** ". By converting the matrix into a string format and applying string operations, this can be done; but is there a simpler way to do it?

-Yeti

Hello,

I am solving a simple system of algebraic equations in a "for" loop. I would like to write all the values of solutions to a matrix, but I only get the symbols. Here is my code:

A:=1:E:=0.1:L0:=<5,5,5,5>:m0g:=0.05:u:=<-5/4,-1/4,-3/4,-1/4>:v:=<-1/2,-3/2,1/2,1/2>:w:=<0,1,0,-1>:
Force:=Matrix(m,2);
for i from 1 to m do
 r1||i:=H||i*L0(i)/(A*E)+H||i/m0g*(arcsinh(V_A||i/H||i)+arcsinh((m0g*L0(i)-V_A||i)/H||i))-sqrt(u(i)^2+v(i)^2);
 r2||i:=V_A||i*L0(i)/(A*E)*(m0g*L0(i)/(2*V_A||i)-1)+H||i/m0g*(sqrt(1+((m0g*L0(i)-V_A||i)/H||i)^2)-sqrt(1+(V_A||i/H||i)^2))-abs(w(i));
 rozw||i:=fsolve({r1||i, r2||i}, {H||i,V_A||i},H||i=0..1);Force(i,1):=H||i;Force(i,2):=V_A||i;subs(rozw||i,Force(i,..));
end do:
evalf(Force);

Thanks in advance,

Iza

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