Hi,

I have a second order, linear, non-homogeneous differential equation and for the solution Maple takes the particular solution under a indefinite integral form. After I substitute the values of the coefficients I want Maple to perform the integration. The integration is possible because I individually integrated one small part of the expression. The full expression has a lenghty sumation of different indefinite integrals so it would be cumbersome to perform each integration by hand.

Can somebody help me force Maple to perform these integrations?

I already tried eval, evalf, simplfy and it doesn't work.

Thanks a lot.

hi

why this equation does not any answer?

thanks

s-s.mw
 

Download s-s.mw

Hi guys,

I run my code and after a point all the numerical values are followed by a dot. Why is that? Also the symbolic variables have a 1. before them.

Thanks a lot!

Hello! Hope everyone would be fine. I want to solve the following system of ODEs please help to find the numerical solution

N := .6; alpha := .4; beta := .1; Nt := .2; Pr := .5; Nb := .1; s := .2; lambda[1] := 1; delta := .5; gm := 1; Sc := 1:L:=1:

Eq1 := (alpha*s+1)*(diff(F(eta), eta, eta, eta))-(F(eta)+(1/2)*s*eta)*(diff(F(eta), eta, eta))+((1/2)*(diff(F(eta), eta))-s)*(diff(F(eta), eta))-2*(G(eta)^2-(1-gm)^2)-2*lambda[1]*(H(eta)+N*Y(eta))-(alpha+beta-(1/4)*delta*(diff(F(eta), eta, eta, eta)))*(diff(F(eta), eta, eta))^2-(alpha-2*beta)*(diff(F(eta), eta))*(diff(F(eta), eta, eta, eta))-(2*(alpha-beta-(1/4)*delta*(diff(F(eta), eta, eta, eta))))*(diff(G(eta), eta))^2-(2*(alpha-(1/4)*delta*(diff(F(eta), eta, eta))))*G(eta)*(diff(G(eta), eta, eta)) = 0; Eq2 := (alpha*s+1)*(diff(G(eta), eta, eta))-F(eta)*(diff(G(eta), eta))+G(eta)*(diff(F(eta), eta))+s*(1-gm-G(eta)-(1/2)*eta*(diff(G(eta), eta)))-(1/2)*alpha*s*eta*(diff(G(eta), eta, eta, eta))+((3/2)*alpha+beta)*G(eta)*(diff(F(eta), eta, eta, eta))-((1/2)*alpha+beta)*(diff(F(eta), eta))*(diff(G(eta), eta, eta))-delta*((diff(F(eta), eta, eta))^2+6*(diff(G(eta), eta))^2)*(diff(G(eta), eta, eta)) = 0; Eq3 := (diff(H(eta), eta, eta))/Pr-F(eta)*(diff(H(eta), eta))+(1/2)*H(eta)*(diff(F(eta), eta))-s*(2*H(eta)+(1/2)*eta*(diff(H(eta), eta)))+Nb*(diff(H(eta), eta))*(diff(Y(eta), eta))+Nt*(diff(H(eta), eta))^2 = 0; Eq4 := (diff(Y(eta), eta, eta))/Sc-F(eta)*(diff(Y(eta), eta))+(1/2)*Y(eta)*(diff(F(eta), eta))-s*(2*Y(eta)+(1/2)*eta*(diff(Y(eta), eta)))+Nt*(diff(H(eta), eta, eta))/Nb = 0;

IC1 := F(0) = 0, (D(F))(0) = 0, G(0) = gm, H(0) = 1, Y(0) = 1; IC2 := (D(F))(L) = 0, G(L) = 1-gm, (D(G))(L) = 0, H(L) = 0, Y(L) = 0; dsys1 := {Eq1, Eq2, Eq3, Eq4, IC1, IC2}; dsol1 := dsolve(dsys1, numeric, output = listprocedure, range = 0 .. L);

dsol1f := subs(dsol1, F(eta));

dsol1g := subs(dsol1, G(eta)); dsol1h := subs(dsol1, H(eta)); dsol1y := subs(dsol1, Y(eta));

With my best regards and sincerely.

Hi,

Seem to be a bit stuck. Here's my code:
 

Thanks in advance :-) 

Hi!

Everyone,

I want to draw  phase plane of system of three fractional order equations. 

Note that 

Also want the  phase portrait when the values of alpha are not same....

Also

Thanks

When print a formula , if variable has power, the power will print in another row

how can it print like a^2 in one row 

Here is one that the students generated which caused confusion. 

a := 0.76;
eq1 := 2*cot(a*sqrt(2*E)) = (2*E-5.4)/(sqrt(E*(5.4-E));
solve(eq1, E)

And the results are: 0., 4.411954070, 2.423743792

The problem is with the second answer because it does not exist. If we plot the LHS and the RHS of eq1 vs E where E=0..5.4

And it gets more interesting, if we calculate:

solve(evalf(eq1), E)

The answers are: 0., 2.423743793, 14.33807304+27.39159712*I

where the 3rd answer is again incorrect.

Finally, if a = 0.8 or larger, the incorrect answers disappear. 

Note - fsolve does handle this problem correctly. And despite my attempts to remind them to use fsolve, they see the solve command as the universal truth. Apparently this will be another teaching moment for next year.

So any thoughts about why this happens and why there is a difference in the outcomes between 0.76 and 0.8 for the value of a?

hi.

how i can dsolve this differential equations?

thanks

ich.mw
 

Download ich.mw

HI everyone,

As can be seen from the attached file, the first three equations of Eq. (5) will render some of the other equations (and other terms) redundant. How can I obtain a simplified system automatically?

Thanks.

Pdesample.mw

Dear all:

I have used the "diff" command in Maple to help me derive a huge and very long function, and now I want to convert this huge expression from Maple to Matlab format, for example, into a Matlab .m file. The format of this expression in Maple is very different from Matlab.

So could you help me with this problem?

Thank you all.

Hello,

In my worksheet (dedicated to the calculations of mechanism geometry), i'm trying to have a more "POO" approach (Programming Oriented Object).

In this sense, I begin to get more familiar with module and package. Attached, you can find a worksheet which gives the idea of the structure of my code. With this code, the module is very useful for me to call some results (attributes in terms of POO).

My way of doing is :
1) at the beginning, i use Maple as a calculator that is to say that at each prompt, i calculate expressions.
2) i try to make modules so as to have a easier access to the data that I calculated.

However, as the definition of the expressions that I calculated are outside my module (for example, in the worksheet attached, i calculate the expression of Gamma and psi before in my worksheet and i retrieve these expressions in the module with "global"), i can not use this module independently of this worksheet and namely in a Excel Addin.

In fact, the module works if the worksheet has been launched one time and consequently the expression of psi and Gamma are in the kernel (or in memory i want to say).

Question:

How can I do to transform my module in a independent and thus portable module ?

One idea will be to copy/ paste all the geometric calculations which have been done line by line inside the module.
However, i have many lines in separated prompts and moreover, it is always convenient to keep the line by line approach in the worksheet to make some tests.

I look forward to hearing your tips.

Thanks a lot for your help

MonPackage_ProcModule_variante4.mw

Hello

Tryed to work this application, but problems encountered.

http://www.maplesoft.com/applications/view.aspx?SID=89020

and

http://www.mapleprimes.com/maplesoftblog/89021-The-Traveling-Salesmans-US-Roadtrip

I installed PostgreSQL, (i believe version 8.4 from 2010) which I found at "oldapps" (the current version is 9.6).

I'm running Win 7, 64 bit. Anyways, I have to change the paths below "Query the database":

driver := LoadDriver(classpath = "C://Program Files (x86)//PostgreSQL//pgJDBC//postgresql-8.4-701.jdbc4.jar");

conn := driver:-OpenConnection("jdbc:postgresql://localhost:5432/zip_codes", "postgres", "password");

I fail to see pgJDBC folder and a search for .jar files in the directory yields only 3 jar files, non resembling the above. tried example.jar

same error. heres a screenshot of my directory

I'm curious to know if anyone has written a procedure to optimize the VRP with time windows / constraints.

How do i implement Runge-Kutta of order 6 for a sytem of boundary value problems on maple