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Error, mismatched or missing bracket/operator-----...

Asked by: Naveshin Jawaheer 15
syntax quotes
September 11 2022
1  3

Hi, everyone! I am a new user to maple and I need to import some code I have found from a paper, just so I can manupluate some of the variables. However when I have copied and pasted my code, I keep getting the error Error, mismatched or missing bracket/operator.  I did check online and it seems to be a bracket missing but I have copied without errors from the source. 

I have attached a picture and did a copy paste of the code that is giving me an error below. 

Thanks for your help 

x[1] := l[1]*sin(theta(t));
y[1] := -l[1]*cos(theta(t));

x[2] := -l[2]*sin(theta(t));
y[2] := l[2]*cos(theta(t));
R[1] := vector(2, [x[1], y[1]]);
R[2] := vector(2, [x[2], y[2]]);
'R[1]'':=map(diff,R[1],t):

 

Why the polysols does not work?...

Asked by: Steven_Huang 105
ode detools differential-equations
September 11 2022
0  1

polysols(diff(u(x), x) = u(x)^2 - 1) produces no results, while it can be verified by direct observation that u(x) = 1 is a polynomial solution.

I need help writing the maple code application?...

Asked by: delvin 60
homework pde dsolve
September 11 2022
0  2

Hi
Can someone help me write the program for this equation?
I really need this program.
With respect

 

Select powers and coeffs on a general type polynom...

Asked by: Ronan 1341
coeff coefficients incomplete-question
September 11 2022
2  4

I was experimenting on and found coeff and degrees  do not work with algebraic type powers. So I set aboud dismanteling  a example polynomial. I certainly went around the houses doing this. I wanted to put the powers and coefficinets of x in an array.

I sure there must be a simpler way.

restart

NULLNULL

r := proc (x) options operator, arrow; a[0]+a[1]*x-a[2]*x^2+a[8]*x^(8/5)-a[h]*x^h+k*x^(-b/a) end proc

proc (x) options operator, arrow; a[0]+a[1]*x-a[2]*x^2+a[8]*x^(8/5)-a[h]*x^h+k*x^(-b/a) end proc

mnmls := [op(r(x))]

[a[0], a[1]*x, -a[2]*x^2, a[8]*x^(8/5), -a[h]*x^h, k*x^(-b/a)]

A := Array(1 .. 2, 1 .. nops(mnmls))

Array(%id = 36893489621187187044)

mnmls, x0 := selectremove(has, mnmls, x)

[a[1]*x, -a[2]*x^2, a[8]*x^(8/5), -a[h]*x^h, k*x^(-b/a)], [a[0]]

NULL

A[2, 1] := op(x0)

a[0]

coeff(r(x), x, 2)

Error, unable to compute coeff

coeffs(r(x), x)

Error, invalid arguments to coeffs

degree(mnmls[1], x)

1

degree(mnmls[4], x)

FAIL

degree(mnmls[5], x)

FAIL

indets(r(x))

{a, b, h, k, x, a[0], a[1], a[2], a[8], a[h], x^h, x^(-b/a), x^(8/5)}

bits := [seq([op(mnmls[i])], i = 1 .. nops(mnmls))]

[[a[1], x], [-1, a[2], x^2], [a[8], x^(8/5)], [-1, a[h], x^h], [k, x^(-b/a)]]

deeperbits := [seq(op(op(bits)[i]), i = 1 .. nops(bits))]

[a[1], x, -1, a[2], x^2, a[8], x^(8/5), -1, a[h], x^h, k, x^(-b/a)]

varpwrs, cofsl := selectremove(has, deeperbits, x)

[x, x^2, x^(8/5), x^h, x^(-b/a)], [a[1], -1, a[2], a[8], -1, a[h], k]

is(nops(vars) = nops(cofsl))

false

cofs := convert(cofsl, Array)

Array(%id = 36893489621220545228)

for i to numelems(cofs)-1 do if cofs[i] = -1 then cofs[i] := 0; cofs[i+1] := -cofs[i+1]; i = i+2 end if end do; cofs; cofs := remove[flatten](has, cofs, 0)

Array(%id = 36893489621220530764)

cofs

Array(%id = 36893489621220530764)

is(nops(vars) = numelems(cofs))

false

NULL

pwrs := `assuming`([simplify(`~`[log[x]](varpwrs))], [x > 0, a::'real', b::'real', h::'real'])

[1, 2, 8/5, h, -b/a]

A

Array(%id = 36893489621187187044)

for i to nops(mnmls) do A[1, i+1] := pwrs[i]; A[2, i+1] := cofs[i] end do; A

Array(%id = 36893489621187187044)

 

NULL


Download Q_11-9-22_monomial_powers_and_coeffs.mw

Unexpected results from pdsolve...

Asked by: Rouben Rostamian 8511
pde pdsolve differential-equations
September 10 2022
2  4
> 

restart;
> 

pde := diff(u(x,t),t) + u(x,t)*diff(u(x,t),x) = 0;

diff(u(x, t), t)+u(x, t)*(diff(u(x, t), x)) = 0

These are all wrong:

> 

pdsolve({pde,u(x,0)=f(x)});
pdsolve({pde,u(x,0)=sin(x)});
pdsolve({pde,u(x,0)=erf(x)});

u(x, t) = 0

u(x, t) = 0

u(x, t) = 0

But these ones are correct:

> 

pdsolve({pde,u(x,0)=exp(x)});
pdsolve({pde,u(x,0)=x});

u(x, t) = LambertW(t*exp(x))/t

u(x, t) = x/(t+1)

Download mw.mw

how to tell Maple not to automatically expand nu...

Asked by: nm 11353
typesetting automatic-simplification inertform
September 10 2022
1  2

in a worksheet, typing

r:=(x^2 - 2*x - 1)/4;

Maple returns

But when typing

r:=(x^2 - 2*x - 1)/(4*x);

Now it does not expand terms and gives what is expected

Is there a way to make the first example remain unexpanded? Same with Mathematica:

I know this only affects the display only. But it is annoying, as I want to see the numerator and denominator on the screen as I put them there and not have them change.

I tried changing the typesetting level, but this had no effect.

I used to like Maple becuase it does not change anything unless asked to, and everything is explicit, which is better.

Now I am starting to change my mind on this aspect of Maple.

Plot Coupled Oscillators ...

Asked by: LegendCero 55
homework plotting oscillator
September 10 2022
1  1

Hello. Is there any way to plot 2+ oscillators as shown in the image below?

Thanks for any help.

Newbie Question...

Asked by: chriskiwi 5
font style zoom
September 10 2022
1  9

Hi,

Newbie here....

I'm struggling to see with the default font size, I'm also struggling with readability of the text/charactors in the left hand paletetes/workbook pull down menus.  I can see that there are style choice options in format>styles but it seems that I need to set every single permutation separately to acheive readability nirvana which seems unlikely to be the best route.

Is there a global setting for font size?  Alternatively are there style files somewhere that the nearly blind can download?

I am really struggling with this.

Cheers

Surface or contour plot of discontinuous function ...

Asked by: ijuptilk 100
contour plotting
September 10 2022
0  10

Please, how do I use surface or contour to plot discontinous function?

z = f(x,y) := x-.8193318913*sin(x)*cos(x)/(cos(x)^2+sinh(y)^2)-(0.2931044702e-2*(0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1))*sin(x)*cos(x)/(((0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1)^2+0.2250000000e-5*x^2*y^2)*(cos(x)^2+sinh(y)^2))-0.4396567053e-5*x*y*sinh(y)*cosh(y)/(((0.7500000000e-3*x^2-0.7500000000e-3*y^2+0.1622336517e-1)^2+0.2250000000e-5*x^2*y^2)*(cos(x)^2+sinh(y)^2)):

Remove limit from integration answer...

Asked by: Ronan 1341
integration assumptions assuming
September 09 2022
1  4

How should I handle the limit in the integration answe?. I don't see why it is necessary.

restart

_local(gamma)

p := `assuming`([proc (alpha) options operator, arrow; alpha^m end proc], [m]); LinearAlgebra:-Transpose(integer)

integer

q := `assuming`([proc (alpha) options operator, arrow; alpha^n end proc], [n]); LinearAlgebra:-Transpose(integer)

integer

Sa := eval((1/2)*(int(simplify(p(alpha)*(D(q))(alpha)), alpha = 0 .. 1)))

-(1/2)*(limit(alpha^(m+n), alpha = 0, right)-1)*n/(m+n)

s1 := eval((1/2)*(int(simplify(p(alpha)*(D(q))(alpha)), alpha)))

(1/2)*alpha^(m+n)*n/(m+n)

eval(s1, alpha = 1)-(eval(s1, alpha = 0))

(1/2)*n/(m+n)

NULL

Download Q_9-9-22_limit_in_integral.mw

What is the convenient way to export a large symbo...

Asked by: mehdibgh 240
matrix matlab export
September 09 2022
0  6

What is the best and accurate way to export a large symbolic matrix (200*300) from Maple to Matlab? The Marix have a lot of variables, symbols and operators such as diiff, int, ....

Here is a simple example:

NULL

> 

restart
> 

NULL
> 

A := Matrix(2, 6, {(1, 1) = x*y*z, (1, 2) = (1/2)*tau[2], (1, 3) = sin(x*y*z), (1, 4) = ln(x*y*z), (1, 5) = tau[1]*exp(x*y*z), (1, 6) = sin(x+y)+cos(x+y), (2, 1) = x^2+1, (2, 2) = x^2+1/sin(x*y*z), (2, 3) = 2*exp(y), (2, 4) = tau[1], (2, 5) = diff(f(x, y, z), x), (2, 6) = int(f(x, y, z), x)})

A := 1/sin(protected)

 (1)
> 

``
> 

CodeGeneration[Matlab](codegen[makeproc](A, [x, y, tau[1], tau[2]]))

Error, (in codegen/makeproc) optional arguments must be equations [x, y, tau[1], tau[2]]

  
> 

``
> 

``
> 

``
> 

``
> 

``
> 

``

Download export.mw

Collection or book of math puzzles for children...

Asked by: Vitro Zhu 69
September 09 2022
0  0

I would appreciate any recommendation on these games and puzzles with maple implementation. The purpose is to inspire the math interest of children (say 16-) . Benefits from the assistance of Maple:

1. Learn and build the habit of math modelling: eg by playing with this n-queen problem - https://www.maplesoft.com/Applications/Detail.aspx?id=154482

Children can realize that, for many problems, modelling is doable for them - question formation in math/programming and finding all the constraints - while solution method is simply a small step if done by computer. This is already a big step forward for them and they may enjoy the modelling process. For more math-eager kids, they may start to explore the documentation behind the solution methods.

2. Learn the art of automatic proof by witnessing the efficiency gain by themselves - I don't think I have to explain such to the community here. I note Doron Zeilberger has collected many in such a spirit on his website.

I have read some in the Application Center (eg under the tag game) and by searching here by the "puzzle". Is there some more systematic collection/books? The applications I have seen is mostly on logical/combinatorial problems. Love to see the games/puzzles under a broader range of math fields good for children.

How to select an undocumented name generated by Ro...

Asked by: mmcdara 7896
solve assumptions type
September 09 2022
1  2

Even though this question is related to this one 
https://www.mapleprimes.com/questions/234781-How-Can-I-Get-The-Desired-Answer-From-solve
feel it is about a different issue. If any of you feel otherwise feel free to move it to the original one.

In this notional example  the name _Z1~ is created by RootOf: and here is an ad hoc way to catch it.

> 

restart:
> 

f := RootOf(cos(x)-z, x):
u := indets(f, name);
s := series(f, z):
v := remove(type, indets(s, name), constant);
w := v minus u

{z}

  

{_Z1, z}

  

{_Z1}

 (1)
> 

 

Download Example_1.mw

In this more complex example an assumption must be made on M to obtain ths desired solution g and the previous method no longer works.

> 

restart
> 

f := 10*cos((-1+t)/sqrt(1+M))-10*cos(t/sqrt(1+M)):
assume(M::nonnegative):
u := indets(f, name);
g := solve({diff(f, t), t>0 }, t, allsolutions)[1][1];
v := remove(type, indets(rhs(g), name), constant);
w := v minus u

{M, t}

  

t = Pi*_Z2*(1+M)^(1/2)-arctan((cos(1/(1+M)^(1/2))+1)/sin(1/(1+M)^(1/2)))*(1+M)^(1/2)

  

{M, _Z2}

  

{M, _Z2}

 (1)
> 

 

Download Example_2.mw

I have tried using select to "capture" the name _Z2~ but I can't know how to distinguish M~ from _Z2~ (is there a type which could be used?).

Can you helpm fix this?
TIA

what is the sign of I*sqrt(3) supposed to be?...

Asked by: nm 11353
differential-equations odetest
September 09 2022
1  6

Is there an assumption or some other way I can tell Maple to avoid such errors when using odetest, as I get many of them.

I think the solution Maple gives is correct. But odetest generates these strange innternal error that it does not know the sign of a complex number.

restart;
ode:=x^2*diff(y(x), x$2) + (cos(x)-1)*diff(y(x), x) + exp(x)*y(x) = 0;
sol:=dsolve(ode,y(x),series):
odetest(sol,ode,series,point=0);

Error, (in odetest/series) need to determine the sign of I*3^(1/2)

I've seen such error many times before and it is still not fixed in release after release.

I am using Maple 2022.1 on windows 10.

Visual Studio Complier: Which version for MapleSim...

Asked by: C_R 3432
compiler
September 08 2022
1  1

To make the "Simple External Code Function" example of the tutorial work, an external complier is required.

in MapleSim:-CreateDataRecord) invalid input: dsolve/numeric/ToExternal:-AddTempFile expects its 1st argument, f, to be of type string, but received [[["f1", 1864151924736]]] (3.597s)

Update:

help(Setup, Compiler) in Maple 2022 provides a link to supported compilers, which are Visual Studio 2017 and 2019.

In the list of available downloads there is no mention of "Express Edition". Which of the packages can be installed alternatively?

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