## Analytical solution...

Hey friends

I want to solve this relation with respect to "M"analytically but maple answer me: "Warning, solutions may have been lost"

How I can solve this problem and get to an analytical solution. It must be noted -1<w<-1/3. we can fix "w" with any value inn this interval. It be accepted any solution for any fixed "w".

Thank you

Analytically_solution.mw

## Weird results from LSSolve when adding constraints...

Hi everyone,

I am desperatly trying to find a reason to those weird results I get using LSSolve. It could really help me to understand, maybe I am using the function the wrong way.
I have a system of equations which is overdetermined that I wrote using an electrical simulation and kirchoff's laws.
I am trying to resolve it using the LSSolve function. Here is the list of residuals :

`list := [-0.444299277411586e-2+(270.100000000000-Phi12_18)*D18, -.264819908561346+(627.030000000000-Phi23_18)*D18, .191242220011840+(-259.080000000000-Phi34_18)*D18, 0.269723795794403e-1+(-40.5060000000000-Phi45_18)*D18, 0.674200455699644e-2+(-10.1270000000000-Phi56_18)*D18, .109534122562258+(-197.290000000000-Phi67_18)*D18, 0.481462872723211e-3+(-2.41420000000000-Phi78_18)*D18, -0.346014532189641e-4+(-2.53290000000000-Phi89_18)*D18, -0.402474969346295e-4+(-2.94150000000000-Phi910_18)*D18, -0.632005430249463e-3+(-8.57100000000000-Phi1011_18)*D18, -0.105749265697549e-1+(-37.6580000000000-Phi1112_18)*D18, -0.116305497595306e-1+(-55.3250000000000-Phi1213_18)*D18, -0.581547498854927e-3+(-2.76630000000000-Phi1314_18)*D18, -0.371408130367776e-2+(-22.0900000000000-Phi1415_18)*D18, -0.886173700610320e-2+(-56.4810000000000-Phi1516_18)*D18, -0.478846208996643e-1+(262.447651185421-Phi12_18)*D29+(262.447651185421-Phi12_24)*D36, .348429199898355+(62.3165310883292-Phi23_18)*D29+(62.3165310883292-Phi23_24)*D36, .237294781239637+(41.8563477700905-Phi34_18)*D29+(41.8563477700905-Phi34_24)*D36, 0.356987380524040e-1+(6.12136413036823-Phi45_18)*D29+(6.12136413036823-Phi45_24)*D36, 0.892515544035472e-2+(1.53042068810978-Phi56_18)*D29+(1.53042068810978-Phi56_24)*D36, .163733792213247+(26.7554245920538-Phi67_18)*D29+(26.7554245920538-Phi67_24)*D36, 0.917897899527287e-3+(-0.110562085900856e-3-Phi78_18)*D29+(-0.110562085900856e-3-Phi78_24)*D36, 0.242480164562623e-4+(-.283316330467957-Phi89_18)*D29+(-.283316330467957-Phi89_24)*D36, 0.281967728090880e-4+(-.329007391842407-Phi910_18)*D29+(-.329007391842407-Phi910_24)*D36, -0.812318100863302e-3+(-1.22850243118112-Phi1011_18)*D29+(-1.22850243118112-Phi1011_24)*D36, -0.174002698946928e-1+(-9.57006175329410-Phi1112_18)*D29+(-9.57006175329410-Phi1112_24)*D36, -.125540933056649+(-44.2197489328973-Phi1213_18)*D29+(-44.2197489328973-Phi1213_24)*D36, -0.627722694977691e-2+(-2.21106159188713-Phi1314_18)*D29+(-2.21106159188713-Phi1314_24)*D36, -0.739424545575381e-1+(-24.8403831529913-Phi1415_18)*D29+(-24.8403831529913-Phi1415_24)*D36, -.203976357415920+(-68.0132712014090-Phi1516_18)*D29+(-68.0132712014090-Phi1516_24)*D36, 0.196522429267177e-1+(197.940000000000-Phi12_24)*D27, 0.368371276889244e-2+(57.8900000000000-Phi23_24)*D27, 0.144256702539785e-2+(48.4450000000000-Phi34_24)*D27, -0.115630146715321e-3+(10.-Phi45_24)*D27, -0.283028527731083e-4+(2.50010000000000-Phi56_24)*D27, -0.300476205822746e-2+(66.2640000000000-Phi67_24)*D27, -0.653509876948917e-3+(2.69040000000000-Phi78_24)*D27, -0.126753046978926e-2+(4.44790000000000-Phi89_24)*D27, -0.147212636486122e-2+(5.16530000000000-Phi910_24)*D27, -0.484316181019253e-2+(16.6000000000000-Phi1011_24)*D27, -0.298854531528585e-1+(96.8770000000000-Phi1112_24)*D27, -.120604432493978+(315.410000000000-Phi1213_24)*D27, -0.603334119632106e-2+(15.7700000000000-Phi1314_24)*D27, -0.664471982996522e-1+(167.170000000000-Phi1415_24)*D27, 0.786913003105101e-1+(-326.760000000000-Phi1516_24)*D27] `

I know that all D values must be positive. When resolving the system without any constraints (D >= 0), i get the values I expected (knowing the input I used in the simulation), with a really low error :

`result := LSSolve(list);`

`[1.82130325886306*10^(-8), [D10 = 0.200009334740825e-2, D11 = 0.666620509302803e-3, D14 = 0.222215208246154e-2, D15 = 0.128202791383597e-2, D17 = 0.499886140344411e-2, D19 = 0.302925526676043e-3, D2 = 0.100002349341980e-2, D20 = 0.142849446596938e-3, D22 = 0.111121127122156e-1, D23 = 0.222228054119820e-2, D25 = 0.714293621502836e-3, D26 = 0.833326349912537e-3, D28 = 0.217396531719902e-3, D3 = 0.400217567900069e-3, D6 = 0.166878862202449e-3, D7 = 0.999969828547956e-2, Phi1011_17 = -1.22850243118112, Phi1011_19 = -20.5335193736012, Phi1011_21 = -104.090964313150, Phi1011_23 = 19.2144499395683, Phi1112_17 = -9.57006175329410, Phi1112_19 = -81.6848630234903, Phi1112_21 = -242.149849175388, Phi1112_23 = 109.001351349915, Phi1213_17 = -44.2197489328973, Phi1213_19 = -92.8267195929548, Phi1213_21 = -204.444165890808, Phi1213_23 = -61.4447612788985, Phi12_17 = 262.447651185421, Phi12_19 = 262.149192406679, Phi12_21 = 256.248405276737, Phi12_23 = 246.521172863223, Phi1314_17 = -2.21106159188713, Phi1314_19 = -4.64255435896474, Phi1314_21 = -10.2212158757032, Phi1314_23 = -3.07798400495386, Phi1415_17 = -24.8403831529913, Phi1415_19 = -30.5944507718603, Phi1415_21 = -45.5847025259923, Phi1415_23 = -77.3297680041818, Phi1516_17 = -68.0132712014090, Phi1516_19 = -74.2023324471993, Phi1516_21 = -95.1952296374558, Phi1516_23 = -132.328467080565, Phi23_17 = 62.3165310883292, Phi23_19 = 200.804225452845, Phi23_21 = 130.018791598707, Phi23_23 = 73.7043262431720, Phi34_17 = 41.8563477700905, Phi34_19 = 343.409987932231, Phi34_21 = 159.593996060841, Phi34_23 = 62.6564757702407, Phi45_17 = 6.12136413036823, Phi45_19 = 12.3839171939746, Phi45_21 = 46.0005281797016, Phi45_23 = 13.1665796516893, Phi56_17 = 1.53042068810978, Phi56_19 = 3.16614687399595, Phi56_21 = 11.4998114891963, Phi56_23 = 3.29093394692614, Phi67_17 = 26.7554245920538, Phi67_19 = -244.288977944524, Phi67_21 = 376.351493538080, Phi67_23 = 88.4830465193635, Phi78_17 = -0.110562085900856e-3, Phi78_19 = -6.28061380389266, Phi78_21 = 43.7035845962372, Phi78_23 = 3.35123473697264, Phi89_17 = -.283316330467957, Phi89_19 = -6.18811507913178, Phi89_21 = -13.9258224376815, Phi89_23 = 5.20325572546379, Phi910_17 = -.329007391842407, Phi910_19 = -7.18580970783931, Phi910_21 = -16.1669897128450, Phi910_23 = 6.04291224185087]] `

When adding the constraints that D should be positive (and that are actually positive in the previous result), I get a worse result in term of precisions :

`LSSolve(list, {D10 >= 0, D11 >= 0, D14 >= 0, D15 >= 0, D17 >= 0, D19 >= 0, D2 >= 0, D20 >= 0, D22 >= 0, D23 >= 0, D25 >= 0, D26 >= 0, D28 >= 0, D3 >= 0, D6 >= 0, D7 >= 0});`

`[0.667302976414869964e-1, [D10 = 0.240199442379079e-2, D11 = 0.666577572133538e-3, D14 = 0.222218786790062e-2, D15 = 0.128192441757651e-2, D17 = 0.278678889056743e-2, D19 = 0.200473317719685e-3, D2 = 0.109938538155804e-2, D20 = 0.840721762649974e-4, D22 = 0.685770482726534e-3, D23 = -1.387530857*10^(-312), D25 = 0.714397733627028e-3, D26 = 0.833201232339238e-3, D28 = 0.204319731851617e-3, D3 = 0.419994015872111e-3, D6 = 0.191996909862889e-3, D7 = 0.103884505319047e-1, Phi1011_17 = -.709707335593168, Phi1011_19 = -15.7863975896827, Phi1011_21 = -151.171843708558, Phi1011_23 = 19.2211409030343, Phi1112_17 = -8.90604676283968, Phi1112_19 = -75.8627539382983, Phi1112_21 = -311.423930967299, Phi1112_23 = 109.002880650927, Phi1213_17 = -54.9212365194647, Phi1213_19 = -89.9790565093006, Phi1213_21 = -250.971671756001, Phi1213_23 = -61.5160003335629, Phi12_17 = 251.480872515883, Phi12_19 = 255.977573006508, Phi12_21 = 254.397100891354, Phi12_23 = 246.524672366158, Phi1314_17 = -2.74614386328796, Phi1314_19 = -4.48401822538664, Phi1314_21 = -12.5381572344771, Phi1314_23 = -3.08154491280567, Phi1415_17 = -31.8947514252141, Phi1415_19 = -30.8090400512349, Phi1415_21 = -51.0499196769535, Phi1415_23 = -77.3268969229600, Phi1516_17 = -87.7947790488482, Phi1516_19 = -75.5403005246575, Phi1516_21 = -101.763771364478, Phi1516_23 = -132.314524393221, Phi23_17 = 94.0093590848714, Phi23_19 = 86.4429757025976, Phi23_21 = 108.554765004168, Phi23_23 = 73.7072279431268, Phi34_17 = 87.6938924370977, Phi34_19 = 82.3922347753764, Phi34_21 = 88.5582078636840, Phi34_23 = 62.6604078051191, Phi45_17 = 13.1910198060107, Phi45_19 = 69.3008595136787, Phi45_21 = 15.5530983566712, Phi45_23 = 13.1677681559684, Phi56_17 = 3.29792072169498, Phi56_19 = 17.4003349272078, Phi56_21 = 3.88187632917493, Phi56_23 = 3.29123115133383, Phi67_17 = 60.0045707036166, Phi67_19 = 54.3070868626015, Phi67_21 = 87.9421288802858, Phi67_23 = 88.4929920125095, Phi78_17 = .279952186311827, Phi78_19 = -3.50632712699693, Phi78_21 = -20.3872167203319, Phi78_23 = 3.35213748642018, Phi89_17 = -0.991299169828910e-1, Phi89_19 = -4.44636683843093, Phi89_21 = 297.888811926331, Phi89_23 = 5.20500671661437, Phi910_17 = -.115101700555720, Phi910_19 = -5.16603761776826, Phi910_21 = 346.033351291632, Phi910_23 = 6.04494564310825]] `

I also get the warning "limiting number of major iterations has been reached".
Can someone explain me?

It may not seem important at first sight, but sometimes when using my program I get wrong values and a negative D, which is not possible. Therefore I try to add a positive constraint, but the LLSolve function doesn't return anything except the error "no improved point could be found", which is weird because when I manually substitute the value I consider correct, i get a really low error. I can show you the related list of equations if you are interested...

Lilian

## why this error message? Error, (in forget) lexical...

the following code results in an error message: Error, (in forget) lexically scoped parameter out of context

If I click on this error message, it brings me to a page which I visited too often.

if I uncomment the irrelevant minimize command, the error message disappears.

How can I prevent this error without giving irrelevant commands?

kind regards,

Harry Garst

## Using wsolve and package charsests for proving geo...

I would like to use method wsolve for solving polynomial equations. The method has been implemented by Wang: https://link.springer.com/chapter/10.1007/978-3-7091-6604-8_9

As it is written in the text the metod is part of charsets package. But I can seem to find it and active it. I can find package online (http://wang.cc4cm.org/charsets.html), but I don't know how to add it to Maple.

I need to use this method in order to prove geometry theorems (and not any other method will do) and compare my results with results of other researchers.

## a problem in fsolve...

hello.i have a problem for solving this equation.i dont why my past post about this is deleted.!!!

thanks,,,

restart:

A1:= 27159:  n:= 0.59:  A2:= 70941:  h0:= 3e-4:
L:= 0.8:  dpx := -98100:  uc:= 0.007:  k:=2.7:

ODE:= (A3,y)->
(h0^(n+1)*L/sqrt(n)*(A1*exp(sqrt(n)*y/L)-A2*exp(-sqrt(n)*y/L))/k+dpx*y*h0^(n+1)/k+A3*(h0)^n/k)^(1/n)
;

 (1)

ODEINT:= proc(A3)
option remember;
local y;
evalf(Int(ODE(A3,y), y= 0..1, epsilon= 1e-7)) - uc
end proc:

ReINT:= proc(A3x, A3y)
Digits:= 15:
Re(ODEINT(A3x + I*A3y))
end proc:

ImINT:= subs(Re= Im, eval(ReINT)):

Digits:= 7:
a3:= fsolve([ReINT, ImINT]);

 (2)

A3:= Complex(a3[]);

 (3)

Solve as IVP:

Digits:= 15:
sol:= dsolve({diff(u(y),y) = ODE(A3,y), u(0)=0}, numeric, range=0..1,  output=listprocedure):

 >
 >

plots:-odeplot(
sol, [[y, Re(u(y))], [y, Im(u(y))]], y= 0..1,
legend= [real, imag], labels= [y, u(y)]
);

Verify that boundary condition at u(1) is satisfied:

abs(eval(u(y), sol(1)) - uc);

sol(.5);

 >

## Solution may have been lost...

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

## Getting more than one result from solve...

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)

## How to plot orthogonal trajectories in differentia...

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,

## invalid if statement termination...

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

## Purchase and Reinstalling ...

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.

## How to make a workbook of a Package, for MapleClou...

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;
# 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

## solve trigonometric system of equation with condit...

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!

## how to check for fopen() status?...

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.

"

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.

## Eigenvalues. Mechanical problem...

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,