Are there any commands in maple that will help me find a suitable function that approximates the numerical solution of:

Download PDEprob2_(2).mw

I am refering to the first graph, is there a way in maple to find an explicit suitable approximating function?

I.e, I want the function to have the same first graph obviously, it seems like addition of exponent and a line function, I tried plotting exp(-t)-0.3*t, it doesn't look like it approximates it very well. Any suggestion on how to implement this task in maple?

Thanks.

I'm have used a program to find the roots of a function 

f:=x*cos(x)-sin(x)*sin(x/1000);
/ 1 \
x cos(x) - sin(x) sin|---- x|
\1000 /

x_max:=50; x_min:=-50; step:=2; i_max:=(x_max-x_min)/step;
50
-50
2
50

j:=1:
for i from 0 to i_max by 1 do
x0:=x_min+i*step;
x[j]:=fsolve(f=0,x=x0);
j:=j+1;
end:

and my output was of the form of multiple "potential" roots and a bunch of which are the same. So I tried to get rid of the ones which were the same before actually finding the ones which ARE roots. To do that I done....

j := 1; for j to 50 do if x[j]-x[j+1] = 0 then ignore(x[j]) else print(x[j]) end if end do:

and it got rid of the ones which are of the above form but some roots are the same and seperated by more than 1 ... i.e x[ j ]= x[j + 2] or some other number. 

Basically I am trying to generalise the above for loop for all "numbers" instead of 1 but when I try some things the for loop doesnt like it. 

Any help would be good!

Say I have an equation of ax^2 + by^2 = 0,

I would like to plot a graph of y^2 against x^2...

How do i do that?

Hello i want to solve the differential equation but i have these problem i don't understand  why !?

restart;
with(LinearAlgebra):
with(student):
P:=180000:
Vt:=P/m;
m:=1.4787880*10^5-t*606.06:
g:=9.81:
T:=176:
pi:=evalf(Pi):

Euler_x := -(diff(lambda3(t), t)) = 0;
Euler_y := -(diff(lambda4(t), t)) = 0;
Euler_Vx := -lambda3(t)-(diff(lambda1(t), t)) = 0;
Euler_Vy := -lambda4(t)-(diff(lambda2(t), t)) = 0;
Euler_theta := lambda1(t)*sin(theta)-lambda2(t)*cos(theta) = 0;
transversalnost:=y(t)-lambda1(t)*Vt*cos(theta)-lambda2(t)*Vt*sin(theta)+lambda2(t)*g-lambda3(t)*Vx(t)-lambda4(t)*Vy(t)=0;

transversalnost:=eval(transversalnost,t=176);

sys:={Euler_x, Euler_Vx, Euler_y, Euler_Vy, theta=arctan(lambda2(t)/lambda1(t)), diff(Vx(t),t)=Vt*cos(theta), diff(Vy(t),t)=Vt*sin(theta)-g, diff(y(t),t)=Vy(t), diff(x(t),t)=Vx(t),x(0)=0, y(0)=0.302, lambda1(0)=0, lambda2(0)=0, lambda3(0)=0, lambda4(0)=0,transversalnost, x(176)=120};

ans:=dsolve(sys, numeric, output=listprocedure):

Error, (in dsolve/numeric/bvp/convertsys) unable to convert to an explicit first-order system

thanks for your help

Hi everyone,

I'm trying to solve the following eqauation but Maple gives me the answer (( RootOf(mexp(-_Z*(m-1))*d^2-theta+_Z*theta-theta*c*t__kj) ))

The equation is:

solve(mexp(-(m-1)*t__ij)*d^2-theta+theta*t__ij-theta*(sum(t__kj, k = 1 .. c))-m*eta*(diff((1-1/exp(t))^m, t)) = 0, t__ij);

Could you please help me??

What is the meaning rootOF? Is there any explicit solution to that equation??

Thank you for your help

Please how do I solve the above 2nd order differential equation (F and K are constants)?

I have the following boundary conditions:

Many thanks!

Hi everyone,

I'm trying to solve the following equation and unfortunately I get this error ( Error, (in Engine:-Dispatch) invalid subscript selector ) each time I try. Could you please help me??

I will be thankful for your great help.

solve(m*exp(-(m-1)*t_ij)*d²-θ+θ*t_ij-θ*(Σ(t_kj, k = 1 .. c))-m*η*(1-exp(-t_ij))^(m-1) = 0, t_ij)

Hello !!

I want to replace the word "assuming" with another word. I tried to write:

> as:=assuming;

> alias(as=assuming);

> `&as`:=proc(a,b) a assuming b; end;

The first two methods are not allowed. The last one doesn't work like "assuming".

Is there any solution to this problem ?

Some time ago, @marc005 asked how he could send an email from the Maple command line.

Why would you want to do this? Using Maple's functionality, you could programatically construct an email - perhaps with the results of a computation - and email it yourself or someone else.

I originally posted a solution that involved communicating with a locally-installed SMTP server using the Sockets package. But of course, you need to set up an SMTP server and ensure the appropriate ports are open.

I recently found a better solution. Mailgun (http://mailgun.com) is a free email delivery service with an web-based API. You can communicate with this API via the URL package; simply send Mailgun a URL:-Post() message that contains account-specific information, and the text of your email.

The general steps and Maple commands are given below, and you can download the worksheet here.

Note: Maplesoft have no affiliation with Mailgun.

Step 1:
Sign up for a free Mailgun account.

Step 2:
In your Mailgun account, go to the Domains section - it should look like the screengrab below (account-specific information has been blanked).

Note down the API Base URL and the API key.

• the API Base URL looks like https://api.mailgun.net/v3/sandboxXXXXXXXXXXXXXXXXXXXXXXXXXXX.mailgun.org.  
• •the API Key looks like key-XXXXXXXXXXXXXXXXXXXXXXXXXX

Step 3:

In Maple, define strings containing your own API Base URL and API Key. Also, define the recipient's email address, the email you want the recipient to reply to, the email subject and email body.

>restart:

>APIBaseURL := "https://api.mailgun.net/v3/sandboxXXXXXXXXXXXXXXXXXXXXXXXX.mailgun.org":

>APIKey:="key-XXXXXXXXXXXXXXXXXXXXXXXX":

>toEmail := "xxxxx@xxxxxx.com":

>fromEmail:="First Last <FirstLast@Domain.com>":

>subject:= "Email Subject Goes Here":

>emailBody := "I'd rather have a bottle in front of me than a frontal lobotomy":

Step 4:
Run the following code

> URL:-Post(cat(APIBaseURL,"/messages"),[

"from"=fromEmail,"to"=toEmail,

"subject"=subject,

"text"= emailBody],

user="api",password=APIKey);

If you've successfully sent the email, you should see something like this (account-specific information is blanked out)

You can also send HTML emails by replacing the "text" line with "html" = str, where str is a string with your HTML code.

This may be a trivial question, but does this factor fully with the newer versions of Maple, say at 900 digits?

Digits:=900;

rho_poly := -2201506283520*rho^32+(-17612050268160+104204630753280*I)*rho^31+(2237195146493952+737798139150336*I)*rho^30+(14065203494780928-29153528496783360*I)*rho^29+(-260893325886750720-161432056834818048*I)*rho^28+(-1240991775275876352+1727517243589263360*I)*rho^27+(8952004373272068096+6696323263091441664*I)*rho^26+(25553042370906292224-37948239682297921536*I)*rho^25+(-135024511500569280512-65293199430849134592*I)*rho^24+(-79740262928225402880+401487130320847241216*I)*rho^23+(956745211126674882560-164797793704574713856*I)*rho^22+(-1213375867282228772864-1655554058430246551552*I)*rho^21+(-1483956336776821211136+3604946201834409820160*I)*rho^20+(6525094787202650144768-1597915397190007586816*I)*rho^19+(-8575469412912592879616-6168391294117580865536*I)*rho^18+(2408139380338842796032+15004449784317106323456*I)*rho^17+(10583091471310114717696-17047513330720373194752*I)*rho^16+(-22619716982813548707840+8898637295768494915584*I)*rho^15+(26538067620972845277184+5129530051326543351808*I)*rho^14+(-21415800164460070789120-17268159356969925234688*I)*rho^13+(11916012071577094946816+22601135173030541677568*I)*rho^12+(-3551246770922037813248-21229478915196610975744*I)*rho^11+(-977434486760953073664+16249214903618313346048*I)*rho^10+(1977414870691507931136-10721551032564274826240*I)*rho^9+(-1197394212949208115968+6172794574205050632192*I)*rho^8+(280273257275327368320-2996290081120136529792*I)*rho^7+(108849195761508531648+1152454823926345101504*I)*rho^6+(-119736267114490955904-327757949185254534784*I)*rho^5+(49149411853848597568+63563541902968683712*I)*rho^4+(-11524495997215059744-7307364351434838944*I)*rho^3+(1585189353379709888+299568910286253408*I)*rho^2+(-116032795768295808+25487628220230528*I)*rho+3299863116538269-2454681763039104*I;;

Good Day Everybody, I m new to maple and would like to translate the following for loop from Matlab to Maple. The FromMatlab Translater didnt work for this expression related to the matrix Q, A, B D and A1. Any help would be greatly appreciated.

Related Matlab Code:

...

Q(3,3)=2*Q(3,3);

 for i=1:length(R)

    T(1,1)=cos(R(i))^2; 

    T(2,2)=cos(R(i))^2; 

    T(1,2)=sin(R(i))^2; 

    T(2,1)=sin(R(i))^2; 

    T(3,1)=-sin(R(i))*cos(R(i)); 

    T(3,2)=sin(R(i))*cos(R(i)); 

    T(1,3)=2*sin(R(i))*cos(R(i)); 

    T(2,3)=-2*sin(R(i))*cos(R(i)); 

    T(3,3)=cos(R(i))^2-sin(R(i))^2;

    T1(1,1)=cos(R(i)); 

    T1(1,2)=-sin(R(i)); 

    T1(2,1)=sin(R(i)); 

    T1(2,2)=cos(R(i));

    Qk(:,:,i)=inv(T)*Q*T; 

    Qk(:,3,i)=Qk(:,3,i)/2; 

    Qk1(:,:,i)=inv(T1)*Q1*T1;

    A=A+Qk(:,:,i)*(h(i+1)-h(i)); 

    B=B+.5*Qk(:,:,i)*(h(i+1)^2-h(i)^2); 

    D=D+1/3*Qk(:,:,i)*(h(i+1)^3-h(i)^3); 

    A1=A1+Qk1(:,:,i)*(h(i+1)-h(i));

end

Thanks a lot in advance.

So I installed copied DirectSearch.hdp and DirectSearch.mla into my Maple2015\lib directory and the program works (all the functions are there) but I cant get help menu by querying ?DirectSearch.

I'm running win7 64bit btw

so under

?hdb

i put this into maple:

HelpTools:-Database:-ConvertAll();

but i get error....

"Converting C:\\Program Files\\Maple 2015\\lib\\DirectSearch.hdb to C:\\Program Files\\Maple 2015\\lib\\DirectSearch.help"
Warning, .hdb help databases are deprecated, 'C:\Program Files\Maple 2015\lib\DirectSearch.hdb' will not be used, see ?HelpTools,Migrate help page for more information
Error, (in HelpTools:-HelpCallUI) cannot create help database: 'unable to open database file'

any clue?

ps I asked the same question for M18 but I managed to get the help to work in that instance.

http://www.mapleprimes.com/questions/204423-Help-Build-For-GlobalSearch-Package

(i also copied DirectSearch.hdp and DirectSearch.mla to Maple2015\bin.X86_64_WINDOWS directory but no joy, there is no .help file created in either bin or lib directories)

(1,1,0), (0,0,0), (0,1,0)

1-0, 1-0, 0-0
0-0, 1-0, 0-0

with(LinearAlgebra):
m := Matrix([[i, j, k], [1, 1, 0], [0, 1, 0]]);
Determinant(m);
1*z = 0;

plot3d(z=0, x=0..1, z=0..1); #this can not plot

0*(x-0) + 0*(y-0) + 1*(z-0) = 0

would like to draw 3d rectangle in 3d plot with one formula

a system of monomials, which has 5 equations for 5 variables , have more than one solutions,

first solution is my wanted solution,

how to eliminate other unwanted solutions?

whether

1. add more equations to eliminate unwanted solutions? how to do?

or

2. edit existing system to eliminate unwanted solutions? how to do?

    a.  add extra terms to some equations?

what is the cause that make it having more than one solutions?

can this reason help to edit existing system?

i succeed with adding extra equation，a1+a2+a3+a4+a5-(6+s) =0  in 3 variables case, it calculate very fast within 1 second.

but when calculating 5 variables, it evaluating a very very long time, what is the problem

without extra equation a1+a2+a3+a4+a5+a6+a7-(1+2+3+4+5+s), it get result within 1 second, but after adding this extra equation, it is like dead loop,

my surface computer run with large fans noise and very hot.

restart;
H := subs(p=diff(f(q,P,t), q), 1/(2*m)*p^2 + 1/2*m*w^2*q^2) = -diff(f(q,P,t), t);
H:=subs( f(q,P,t) = f1(q) + f2(t), H);
sol:=dsolve({rhs(H)=E,lhs(H)=E});
S:=rhs(sol[1][1]+sol[1][2]);
subs(m=1, diff(S,q));
p := (E, w) -> -(1/2)*sqrt(-q^2*w^2+2*E)+(1/2)*q^2*w^2/sqrt(-q^2*w^2+2*E)-E*(sqrt(w^2)/sqrt(-q^2*w^2+2*E)+sqrt(w^2)*q^2*w^2/(-q^2*w^2+2*E)^(3/2))/(sqrt(w^2)*(1+w^2*q^2/(-q^2*w^2+2*E)));
lst := [seq(p((1/2)*E, w), E=0..5),seq(-p((1/2)*E, w), E=0 .. 5)]:
plot(lst, w= -3*Pi..3*Pi, color = black, numpoints=1000);

Q is the new coordinate which is diff(S,E)

t0 is the time when argument of solve(subs(m=1, diff(S,E))=0, t) vanish
initialq := solve(solve(subs(m=1, diff(S,E))=0, t)=0, q);

after find the initial value, how to plot with new coordinate?

dsolve({H, q=0}, f(q,P,t));

i try another way to do

restart;
H := subs(p=diff(f(q,P,t), q), 1/(2*m)*p^2 + 1/2*m*w^2*q^2) = -diff(f(q,P,t), t);
H:=subs( f(q,P,t) = f1(q) + f2(t), H);
sol:=dsolve({rhs(H)=E,lhs(H)=E});
S:=rhs(sol[1][1]+sol[1][2]);
p2 := subs(m=1, diff(S,q));

initialq := solve(solve(subs(m=1, diff(S,E))=0, t)=0, q);

H := subs(p=p2, 1/(2*m)*p^2 + 1/2*m*w^2*q^2) = -diff(f(t), t);
H := subs(w=theta(t), H);
sol := dsolve({H, q=0}, numeric, range = 0 .. 30);
odeplot(sol, [t, theta(t)], refine = 2);

Error, (in dsolve/numeric/process_input) invalid specification of initial conditions, got q = 0