MaplePrimes Questions

I try to use phaseportrait to get the phase portrait of the following ode system, why it does not give the plot or the error reminding?


 

with(LinearAlgebra)

phaseportrait([diff(x(t), t) = -((y(t)^2*x(t)+x(t)^3+y(t)-x(t))*sqrt((y(t)^2+x(t)^2)/x(t)^2)-2*x(t))*x(t)/sqrt(y(t)^2+x(t)^2), diff(y(t), t) = -x(t)*((y(t)^3+y(t)*x(t)^2-y(t)-x(t))*sqrt((y(t)^2+x(t)^2)/x(t)^2)-2*y(t))/sqrt(y(t)^2+x(t)^2)], [x(t), y(t)], t = 0 .. 50, [[x(0) = -1, y(0) = -1], [x(0) = -5, y(0) = -5]], x = -10 .. 20, y = -10 .. 30, dirgrid = [40, 40], stepsize = 0.1e-2, numframes = 90, axes = BOXED, linecolor = black)

phaseportrait([diff(x(t), t) = -((y(t)^2*x(t)+x(t)^3+y(t)-x(t))*((y(t)^2+x(t)^2)/x(t)^2)^(1/2)-2*x(t))*x(t)/(y(t)^2+x(t)^2)^(1/2), diff(y(t), t) = -x(t)*((y(t)^3+y(t)*x(t)^2-y(t)-x(t))*((y(t)^2+x(t)^2)/x(t)^2)^(1/2)-2*y(t))/(y(t)^2+x(t)^2)^(1/2)], [x(t), y(t)], t = 0 .. 50, [[x(0) = -1, y(0) = -1], [x(0) = -5, y(0) = -5]], x = -10 .. 20, y = -10 .. 30, dirgrid = [40, 40], stepsize = 0.1e-2, numframes = 90, axes = BOXED, linecolor = black)

(1)

``

``


 

Download m40.mw

 

I was wondering if there was any way to reassign the "||" operator to calculate parallel resistors?

like this:

R1 || R2 = (1/R1+1/R2)^(-1)

 

solve it by Maple , get the following form solution, what's the Int(1,0)

 


 

restart;

 

ODE :=diff(r(t),t)=r(t)*(1-r(t)^2)+mu*r(t)*cos(t)

diff(r(t), t) = r(t)*(1-r(t)^2)+mu*r(t)*cos(t)

(1)

dsolve(ODE)

r(t) = ((_C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t)))*exp(2*t+2*mu*sin(t)))^(1/2)/(_C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t))), r(t) = -((_C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t)))*exp(2*t+2*mu*sin(t)))^(1/2)/(_C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t)))

(2)

g := unapply(sqrt((C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t)))*exp(2*t+2*mu*sin(t)))/(C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t))), t)

proc (t) options operator, arrow; ((C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t)))*exp(2*t+2*mu*sin(t)))^(1/2)/(C1+2*(Int((exp(t))^2*(exp(mu*sin(t)))^2, t))) end proc

(3)

g(0)

1/(C1+2*(Int(1, 0)))^(1/2)

(4)

``


 

Download m39.mw
 

How can I  get the  phase portrait  and several trajectory of the following system(it is in polar coordinates )

r'=r(1 − r^2) + 2rcos(θ),

θ' = 1

 

I'm working along in Maple 2019 and then all of a sudden it freezes.  Anyone else have this?

Maple 2018 and earlier displayed an Array like this

In Maple 2019 I get this

How do I display Arrays in Maple 2019 like Maple 2018?

Why when I read a file in (image file - specifically a TIFF file) and then write the exact same file back out, it makes a file 30% larger.  Should it not be the same size??

Trying to solve this integral here. 

restart;
with(Statistics);

X := RandomVariable(Normal(10, mu));
                            X := _R
dummy := int(PDF(X, mu), r = -infinity .. 500);
                         /   /           2\\         
                         |   |  (mu - 10) ||         
                         |exp|- ----------||         
                         |   |        2   ||         
                         |   \    2 mu    /|         
          dummy := signum|-----------------| infinity
                         \       mu        /         
solve(dummy = 0.05);
 

What am I missing? Any ideas ? :)

Please excuse this newbie question - but any idea what's wrong with this procedure?

I also wonder how text indent and formatting is done in Maple? Are there any tricks, or is it just doing formatting that it look good.

Last thing - what's the best procedure to post questions like this? Is it just attaching a short code example in original Maple file, or do I copy & paste as text?


 

Warning, premature end of input, use <Shift> + <Enter> to avoid this message.

 

assign('`f__t,90,k`', Property(Class, "f_t,90,k"));
       assign('`f__c,0,k`', Property(Class, "f_c,0,k"));
     assign('`f__c,90,k`', Property(Class, "f_c,90,k"));
     assign('`f__v,k`', Property(Class, "f_v,k"));
     assign('`f__r,k`', Property(Class, "f_r,k"));
     assign('`E__0,mean`', Property(Class, "E_0,mean"));
     assign('`E__0,05`', Property(Class, "E_0,05"));
     assign('`E__90,mean`', Property(Class, "E_90,mean"));
     assign('`E__90,0,05`', Property(Class, "E_90,0,05"));
     assign('`G__mean`', Property(Class, "G_mean"));
     assign('`G__0,05`', Property(Class, "G_0,05"));
     assign('`G__r,mean`', Property(Class, "G_r,mean"));
     assign('`G__r,0,05`', Property(Class, "G_r,0,05"));
     assign('`rho__k`', Property(Class, "rho_k"));
     assign('`rho__mean`', Property(Class, "rho_mean"))

Error, reserved word `end` unexpected

 

``


 

Download proc.mw

How Do I set the Command Line Font in Maple 2019?

The default font is strange.  eq is displayed as a a lower case char like '8' followed by 'q'.

I would like to have something like courier 10, etc.

Hi, I am using the GroupTheory package and I wanted to created the following group in Maple:

I stumbled across this link https://www.maplesoft.com/products/maple/features/grouptheory.aspx and then tried to use the following commands to define this group in Maple:

1. First a defined a 12x12 matrix:

ct := <<e | p | q | r | s | t | u | v | w | x | y | z>, <p | q | e | y | u | w | z | r | x | t | v | s>, <q | e | p | v | z | x | s | y | t | w | r | u>, <r | z | t | s | e | y | v | x | p | u | q | w>, <s | w | y | e | r | q | x | u | z | v | t | p>, <t | r | z | x | w | u | e | q | y | p | s | v>, <u | x | v | p | y | e | t | z | s | r | w | q>, <v | u | x | z | q | r | y | w | e | s | p | t>, <w | y | s | t | x | z | p | e | v | q | u | r>, <x | v | u | w | t | s | q | p | r | e | z | y>, <y | s | w | u | p | v | r | t | q | z | e | x>, <z | t | r | q | v | p | w | s | u | y | x | e>>

 

2. Then I tried to define my  group using:

G := Group(ct)

 

However this doesn't work because I get the following error:

Error, (in GroupTheory:-Group) invalid input: arguments to GroupTheory:-Group, [Matrix(12, 12, {(1, 1) = e, (1, 2) = p, (1, 3) = q, (1, 4) = r, (1, 5) = s, (1, 6) = t, (1, 7) = u, (1, 8) = v, (1, 9) = w, (1, 10) = x, (1, 11) = y, (1, 12) = z, (2, 1) = p, (2, 2) = q, (2, 3) = e, (2, 4) = y, (2, 5) = u, (2, 6) = w, (2, 7) = z, (2, 8) = r, (2, 9) = x, (2, 10) = t, (2, 11) = v, (2, 12) = s, (3, 1) = q, (3, 2) = e, (3, 3) = p, (3, 4) = v, (3, 5) = z, (3, 6) = x, (3, 7) = s, (3, 8) = y, (3, 9) = t, (3, 10) = w, (3, 11) = r, (3, 12) = u, (4, 1) = r, (4, 2) = z, (4, 3) = t, (4, 4) = s, (4, 5) = e, (4, 6) = y, (4, 7) = v, (4, 8) = x, (4, 9) = p, (4, 10) = ...  (12, 8) = s, (12, 9) = u, (12, 10) = y, (12, 11) = x, (12, 12) = e})], do not match any of the accepted calling sequences

 

I don't know what's going wrong. It doesn't give a 2D Plot. Thanks in advance.

Temperature over 24hr period

 

y := 0.26e-1*x^3-1.03*x^2+10.2*x+34, 0 <= x and x <= 24

``

``

 

NULL


 

Download temperature24hr.mw

BE312-1920-CW2-Amended-Maple-Codemw-46469mw-46557_(1).mw

 

How do you run this code in Maple 2019 to Maple 18 because I can't see the output?

Thank you

I thought the easiest way to show the world map, a projected flat map into 3d was to use the builtin one and just transform it.  You can zoom into it and rotate it no problem but unforunately it's not as clean as I thought.  Is it possible to have cleaner shading manipulating the Builtin map to 3d?

with(plots):
with(plottools):
with(DataSets):
with(Builtin):
m := WorldMap():
m1 := Display(m)
                                

to3d := transform((x, y) -> [x, y, 0]):
m2 := to3d(m1)
                               

display(m2)

 

 

If a maple command or function are not available on the target language  of the code generation of maple, is it possible to set myself the expected output for such cases so that the Csharp(...)  recognizes the cases and generates the expect code?

for example 

h := proc(x::Array(1 .. 3, 1 .. 3), y::Array(1 .. 3, 1 .. 3)) local z; z := evalm(x &* y); return z[1, 1] + z[2, 2]; end proc;
CSharp(h);

The function names {`&*`, evalm} can not be recognized in the target language

but for the &* it shoud be easy to add a template with the desired C# output. 

Is it possible to add templates in existing languages but not new language definitions?


 

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