Hi,

I want to solve this equation with respect to M, But Maple answer me: "solution may have been lost"

How I can solve this equation?

Thanks guyz

Solutionmayhavebeenlost.mw

Greetings Sirs,

I have recently aquired Maple for some mathematics, and being a new user, I basically google for everything at the moment.

While it has gone well so far, I seem to have hit a bump that I cannot figure out.

I have a function: f(x)=3.2+0.4sin(1.25x), 0<x<5

Trying to find the places where "f(x)=3.5" would normally be done with the equation "3.5=3.2+0.4sin(1.25x)", and when I solve for the equation in Maple I get a solution too.

Problem is though, I know there is supposed to be multiple solutions. Having used wolframalpha, and being capable of seeing the plot in Maple, I know there is two points within the period "x=0..5" that is the solution.

But when I try to solve the equation, I get only one solution per solve, and the second solve doesn't make much sense for me. These are what I use:

As you can see, in the first solve the entire function is being taking into consideration, yet I only get one solution... In the second solve I have tried specifying a period, but I still only get one solution.

Basically any help here is appreciated, because from what I understand, having read google, the solve command or fsolve command is supposed to give multiple results if they are there.

With appreciation,
Ciesi

(Edit: Image size changed)

Dear sir, 

I request your kind help with regard to the above cited subject.

With warm regards.

Mr.M.Anand

Associate Professor in Mathematics.

Aurora's Technological & Research Institute, 

Hyderabad-INDIA

Hi,

While running a maple code, I am getting a "invalid if statement termination" error. Most of time when I use nested for loop and if statement inside the loop, I am getting this error. Another error I get frequently is "Error, unterminate loop". I am using "shift+Enter" instead of Enter to avoid blanks but still such error appears. Can any one provide some rules which I should keep in mind to avoid these errors. My maple worksheet is enclosed-

invalid-if-stat-term-error.mw

Thanks and Regards,

Nilesh

 To Whom It Might Concern,

I purchased Maple on Jun 5, 2017 for my Window laptop. However, my harddrive in my laptop was broken and i lost all my stuff including Maple. I am using my husband's laptop right now. How can re install Maple? I still have the transaction number (removed). Would you let me know what I can do to re-install the software? Also, my husband's laptop is a Mac. 

I am looking forward to hearing from you.

Nancy Phu.

I would like to create a Maple Workbook of my Lattice Package so I can put it on MapleCloud. I had an email exchange with Daniel Skoog from Maplesoft about this, and he even sent me an example that looked easy enough to adapt to my purposes. Alas, it does not work. Here is the code I wrote to assemble the already extant files:

restart;
                "Maple Initialization loaded..."
# Build Lattice workbook following example from Daniel Skoog, MapleSoft:
currentdir();
 "/Applications/Math_Calc/Maple 2015/Packages/Lattice/Lattice

    Version 1.1.0 release files"
# We have all files already from the App Center submission, so just assemble the workbook
PackageTools:-Create("Lattice.maple",\
"MLA file"="Lattice.mla",\
"Lattice.help",\
"Source"="Lattice1.1.mpl",\
"Build procedure"="Lattice1.1.mw",\
"Manual"="The Lattice Package Users Guide.mw",\
"Release Notes"="V1.1 Release Notes.rtf");
Error, (in march) unable to attach worksheet file The Lattice Package Users Guide.mw

When I look at the created workbook (Lattice.maple), the only members included are Lattice.help, the Build procedure Lattice1.1.mw and the source file Lattice.mpl. In particular, Lattice.mla is not there, which is the most important one.

What am I doing wrong? What does "march" (which sounds like machine architecture) have to do with it??

I also don't quite know how to "install" it. I assume I just put the whole workbook into a directory accessible through libname ?

Mac Dude

PS: I could have sorted this privately with Daniel, but this may be of interest to others as well so I hope he'll answer through this forum.

Lattice1.1_workbook_maker.mw

I want to solve this equation with assumptions!!!

restart;
assume(d::real, d>0):
assume(a::real, -0.01 < a, a < 0):
sys:={-800*Pi*a*cos(6.557377048*Pi*(3.470797713+d))/(a+1)^3 = -.9396060697, 800*Pi*a*sin(6.557377048*Pi*(3.470797713+d))/(a+1)^3 = -.3238482794};
solve(sys, {a,d},useassumptions=true, AllSolutions=true);

one of the solutions has true "a" but "d" is wrong, I want one true solution!

Maple help pages are terrible.  Sorry, but this is true.

I am looking for one example of how one is supposed to open a file and correctly check that the open was successful and no error occured, all done in code. As in a script.

All what help in fopen says is that if this and that, it generates an error.

            "otherwise, fopen generates an error. "

OK. But to check for this in code? Why not show an example? the help page on iostatus just lists possible errors. Again, not a SINGLE example of actual Maple code showing how to actually check or handle an error. It just says to call iostatus() and shows the output without an example of what to do next and what to check for.

Lets say one does this:

fileName := "C:\\foo.txt";
fd       := fopen(fileName,WRITE):

Now what? How to check the above was successful? Do I need a trap and catch? catch what? Do I need to check for fd being greater or equal to zero and also use trap in addition? And if an error happens, how to know what it is? How to to format the message, etc.. all in CODE (not interactive) and not by saying just look at the screen and see if there is an error message.

Spend 30 minutes in the help pages and could not find ONE example that shows how to actually check for errors.

I have no idea who writes Maple helps pages, but I find the help pages useless most of the time.

Compare the help for linux fopen for example, where is gives exact details of how to handle the error and find the exact error, all in code.

I solve a mechanical exercise but i had a problem.

I know M (mass) and K (stifness) matrices (4x4).

I want to solve the (λ²M+K)v=0  eigenvalue problem, where λ are the eigenvalues and v eigenvectors.

How can i solve this problem.  I tried with the Eigenvectors() command but it didn't give the right solution.

The Eigenvalues are okay, but the eigenvectors not

K := Matrix([[4*10^7,-1.50*10^7,2*10^7,0],[-1.50*10^7,1.50*10^7,0,1.50*10^7],[2*10^7,0,8*10^7,2*10^7],[0,1.50*10^7,2*10^7,4*10^7]]);

M:=Matrix([[121.90,99.048,-91.429,0],[99.048,594.29,0,-99.048],[-91.429,0,243.81,-91.429],[0,-99.048,-91.429,121.90]]);

w1,w2:=Eigenvectors(K,M);

Acoording with the book the right eigenvectors(shape mode) are:

[0.013 991,  0.034 233,  0.073 683,  0.090 573]
[0.035 637, 0, -0.032 213, 0]
[0 ,-0.034 233, 0, 0.090 573]
[-0.013 991, 0.034 233, -0.073 683, 0.090 573]

Thank you
 

Hi,
I have aproblem saving procedures. I am using Linux Mint 18.2, KDE, 64 Bit. Everything works (at least what I used until now) except:
when trying to use save "save(kgVnat,"kgVnatproc.m") I get an error message "Error, permission denied: no write access (kgVnatproc.m)". Now - the work direcxtory is "/home/username" - in the status bar as well as per currentdir() or currentdir(kernelopts(homedir)) . I can create and save files there - and also in the working directory of maple "/home/username/Studium/Maple" by using a file manager or a text editor - everything else would anyway be surprising when using home/username directory. So it has to be something else ...
I can save the worksheet as a whole without any problems in "/home/username/Studium/Maple". Also I tried to use currentdir(..) to change to the directory explicitely and then saving the proecdure, but again, "..access denied" even though worksheets are saved without error...

Anyone any idea?

Kind regards Udo

Hi, i have a problem with subs instruction. I'd like to change a function D(s) with symbol d/ds d(t), but i won't to calculate derivate, I want only change symbol. Thanks a lot.

Sometimes dsolve returns solution as implicit, even when not using the `implicit` option. For example

restart;
ode:=diff(y(x),x)=(x*y(x))^(1/2):
sol:=dsolve(ode,y(x));

Gives

Which is the same result if I had used 'implicit'.

Is there a way to tell dsolve not to do this? is it becuase it can't solve for y(x) from the above?

Maple 2017.1

i want to draw plot Y[1] . but i cant. thank you

restart;
with(LinearAlgebra); Digits := 15; with(plots); with(Optimization);;
NewM := Matrix(5, 5, [[4119700.0000, 0., 0., 0., 0.], [0., 175900.0000, 0., 0., 0.], [0., 0., 52796., 0., 0.], [0., 0., 0., 2002900.0000, 0.], [0., 0., 0., 0., 21711.]]); NewK := Matrix(5, 5, [[18278000.0000, 0., 0., 0., 0.], [0., 8478500.0000, 0., 0., 0.], [0., 0., 3874800.0000, 0., 0.], [0., 0., 0., 494710000.0000, 0.], [0., 0., 0., 0., 7707500.0000]]); L := Vector[column](5, [400689.480747934, 36882.2103608425, 24223.1756570268, 7197.48654698287, 5007.64668721342]); V := Vector[column](5, [4.43679672962542, 48.2014976972537, 73.3916065733549, 246.999805581163, 355.012621460930]);
Phi := Matrix(5, 5, [[1., 1., 1., 1., 1.], [1.96506022575420, 1.62041320563413, 1.42204109823483, 0.548765310483432e-1, -.795724394004826], [9.21473910149806, 2.36597630710861, -.837387679777313, -8.23805381555997, 0.930594200639915e-1], [10.5672146719479, 1.26937656539014, -.710851068914949, 12.5801876194058, -0.564138989400088e-1], [12.4282433098880, -2.02516824673162, .481291188486771, -1.71479964168293, 0.513709374343217e-2]]);
NS := ImportMatrix("D:/tabas.txt", datatype = float[8]);
t_NS := NS[() .. (), 1];
acc_NS := NS[() .. (), 2];
plot(NS, t = 0 .. 4.5, size = [800, 400]);
acc := unapply(CurveFitting:-Spline(t_NS, acc_NS/(9.81), t, degree = 1), t);
eq := seq(diff(x[i](t), t$2)+(2*0.5e-1)*sqrt(V[i])*(diff(x[i](t), t))+V[i]*x[i](t) = L[i]*acc(t)/NewM[i, i], i = 1 .. 5, 1);
ic := [seq({x[i](0) = 0, (D(x[i]))(0) = 0}, i = 1 .. 5, 1)];
sol := seq(dsolve({eq[i], ic[i][]}, numeric, output = listprocedure), i = 1 .. 5, 1);
Z := `<,>`(seq(sol[i][2], i = 1 .. 5));
#Y := Phi . Z;
#odeplot(Y[1], t = 0 .. 10);
tabas.txt

1.mw

when i want to get awenser i have to solve it for 36 equation and 36 variabales
but maple will not give me a solution (just toss me back my variabales ) i dont know whats wrong
it will give me an awenser for lower like 20equ and 20var ?
parameters :

there is m for power an equation (equation^m) its between 2 , 2.5 , 3 , 4
and N give 2N+2var and 2N+2equ
its a hard calculation i copy it here hope u get it

h= "a number "

p := proc (x) c[-N-1]*x^2+1 end proc

dp := diff(p(x), x)

ddp := diff(p(x), x, x)

DELTA2 := piecewise(k <> j, -2*(-1)^(j-k)/(j-k)^2, k = j, -(1/3)*Pi^2)/h^2

DELTA1 := piecewise(k <> j, (-1)^(j-k)/(j-k), k = j, 0)/h

DELTA0 := piecewise(k <> j, 0, k = j, 1)

PHI := proc (x) ln(sinh(x)) end proc

dPHI := diff(PHI(x), x)

ddPHI := diff(PHI(x), x, x)
 

for i from -N-1 to N do x[i] := ln(exp(i*h)+(exp(2*i*h)+1)^(1/2)) end do

variabales : c[-N-1],c[-N],c[-N+1]...c[N-1],c[N] total 2N+2 var

My equations

POL := seq(simplify(eval(sum(c[k]*((eval(2*dPHI*DELTA1), x = x[j])+eval(x[j]*ddPHI*DELTA1, x = x[j])+x[j]*(eval(dPHI^2, x = x[j]))*DELTA2), k = -N .. N)+eval(ddp, x = x[j])+2*(sum(c[k]*(eval(x[j]*dPHI*DELTA1, x = x[j])+DELTA0), k = -N .. N)+eval(dp, x = x[j]))/x[j]+(c[j]*x[j]+p(x[j]))^m, x = x[j])), j = -N-1 .. N)

solving

K := fsolve({seq(POL[v] = 0, v = 1 .. 2*N+2)})

it can calculate for m=2.5 , N=15 , h=0.29669

if you can calculate it for m=3 , N=17 , h=0.41600

i want to draw plot Y[1] . but i cant. thank for you

i want to take this equation

restart;
with(LinearAlgebra); Digits := 70; with(plots);

K := Matrix(5, 5, [[18278000.0000, 0., 0., 0., 0.], [0., 8478500.0000, 0., 0., 0.], [0., 0., 3874800.0000, 0., 0.], [0., 0., 0., 494710000.0000, 0.], [0., 0., 0., 0., 7707500.0000]]); M := Matrix(5, 5, [[4119700.0000, 0., 0., 0., 0.], [0., 175900.0000, 0., 0., 0.], [0., 0., 52796., 0., 0.], [0., 0., 0., 2002900.0000, 0.], [0., 0., 0., 0., 21711.]]); L := Vector[column](5, [400689.48, 36882.21, 24223.175, 7197.4865, 5007.6466]); V := Vector[column](5, [4.4368, 48.201, 73.39160, 246.999, 355.012]);
NS := ImportMatrix("D:/tabas.txt", datatype = float[8]);
t_NS := NS[() .. (), 1];
acc_NS := NS[() .. (), 2];
plot(NS, t = 0 .. 4.5, size = [800, 400]);
acc := unapply(CurveFitting:-Spline(t_NS, acc_NS/(9.81), t, degree = 1), t);
eq := seq(diff(x[i](t), t$2)+(2*0.5e-1)*sqrt(V[i])*(diff(x[i](t), t))+V[i]*x[i](t) = L[i]/M[i, i], i = 1 .. 5, 1);
ic := [seq({x[i](0) = 0, (D(x[i]))(0) = 0}, i = 1 .. 6, 1)];
res := evalf(seq(dsolve({eq[i], ic[i][]}, numeric, method = rkf45), i = 1 .. 5, 1));
Z := `<,>`(res[1], res[2], res[3], res[4], res[5]);
Y := Phi . Z;
#odeplot(rhs(Y[1]), t = 0 .. 4)

import file text

tabas.txt