Dear friends!

Hope you would be fine. I want to solve the following system of ODEs

restart; L := 1; with(plots); Digits := 30;

a[1] := 0; a[2] := 1; a[3] := 2; a[4] := .2; a[5] := 4; a[6] := 6;

S := 1; Pr := 6.2; a := 1; a1 := 1; a2 := 1; lambda := 1; delta := 1; Bi := 1; A := 1; B := 1;

HA := [a[1], a[2], a[3]];

Eq1 := diff(F(eta), eta, eta, eta)+a*(a1*((F(eta)+G(eta))*(diff(F(eta), eta, eta))-(diff(F(eta), eta))^2)-M1*(diff(F(eta), eta))) = 0;

Eq2 := diff(G(eta), eta, eta, eta)+a*(a1*((F(eta)+G(eta))*(diff(G(eta), eta, eta))-(diff(G(eta), eta))^2)-M1*(diff(G(eta), eta))) = 0;

Eq3 := (A+B)*(diff(H(eta), eta, eta))+a2*Pr*(F(eta)+G(eta))*(diff(H(eta), eta)) = 0;

IC1 := F(0)+G(0)=0, (D(F))(0) = 1+delta*((D@@2)(F))(0), (D(G))(0) = lambda+delta*((D@@2)(G))(0), (D(H))(0) = -Bi*(1-H(0)), (D(F))(L) = 0, (D(G))(L) = 0, H(L) = 0;

params := {B111 = .2};
associated with the above (mentioned as red) boundary conditions. The problem which I faced in first condition i.e., F(0)+G(0)=0 because its combine condition for F(eta) and G(eta) which should be use for both function. The rest part of my program is below:

for k to nops(HA) do;

P || k := plots:-odeplot(dsolve(eval({Eq1, Eq2, Eq3, IC1}, `union`(params, {M1 = .5, phi = HA[k]})), numeric), [[eta, diff(F(eta), eta)]], linestyle = [solid, solid, solid, solid][k], color = [red, green, blue, red][k], labels = [eta, f], thickness = 3) end do;

f1 := plots:-display(P || (1 .. nops(HA)));

display(f1, axes = boxed, size = [380, 310], title = "Ethylene glycol/Cu: M = 2, S = -5", titlefont = ["Arial", 12, bold]);

Please fix my problem ASAP. I also attach the maple file. Thanks in advance.

Help.mw

g3 := tanh(x+1);
a:=eval(diff(g3,x$n)/n!, x=0) assuming n>=0:
tanhx := sum(a*x^n, n=0..infinity):
tanhx2 := subs(x^n=subs(_C1=0, subs(t=n!, g2))*x^n, tanhx):
diff(tanhx2, x) - tanhx2;
 

would like to find a operator to make it equalt to itself , a new differential operator for new transcendental function tanhx2

g3 := 2*(1+exp(4*x))/(exp(4*x)-1);
a:=eval(diff(g3,x$n)/n!, x=0) assuming n>=0:
hello := sum(a*x^n, n=0..infinity):

it run a very long time like endless
 

Dears,

I have seen a Mathematica code which I would like to have it in Maple, since I do not know that program. Let f(z) an analytic function, say f(z):=1+2^{z+1}+3^{z}. To find the roots of f(z) in a regingion, we can use in Maple the command "Analytic" (of the package "RootFinding"). However, in Mathematica is used the following:

L = 20; Monitor[zeros = Flatten@Table[N[z /. Solve[f[z] ⩵ 0 && k L ≤ Re[z] ≤ k L + L && -10 < Im[z] < 10, z], 25],{k, 300}],k];

What means the "N[z/. Solve..." instruction? Also, the following command:

SortBy[zeros, Re]; 

Can be "translated" to Maple?

Many thaks in advance for your comments!

With Regards,

G.

Hi there,

The command

           dsolve(MyOde, numeric, range=MyRange, method=rosenbrock, output=piecewise)

returns a list of solution pieces which is not sufficiently dense according to how I intend to use it.


Is there a possibility to impose the "number of pieces" or the positions of the "breaks" in this command ?

Thanks in advance for any suggestion.

my problem is how to put the third order IVP in derivate code for solving third order problems

the problem is y'''+2y"-9y'-18y=18x^2-18x+22

Digits := 18;
with(LinearAlgebra);
f := proc (n) -----;

derivative

g := proc (n)----- ;

please i need to know to to reresent it in the f := proc (n) and g := proc (n) where g := proc (n) is the derivative of f(x).

please any help 

Hi everybody,

I want to plot many curves in the form of a table.

For instance, let    p := plot(x, x=0..1, labels=[x*Unit('m'), y*Unit('m')]):

The command   plots:-display(p)  returns a plot  with labels x [[m]] and y [[m]], just as expected.

But the commands (remember I have several plots)
                             plots:-display(<p>);                              # and the generalization plots:-display(<p | p>)
                             DocumentTools:-Tabulate([p]);           # and the generalizationDocumentTools:-Tabulate([p,p])
both provide labels  x Units:-Unit('m') and  y Units:-Unit('m')

Is there a way to fix this and obtain plots withe the expected labels ?

Thank to all of you for yout help

 i need a help on how to find the local truncation error of a hybird block method of three order IVP. here is the one of the discrete methods i need to find the local truncation error. please any solution should put here thanks 

The following image shows a .mw file on two monitors (1 = right side) (2 = left side).  

Distortion occurs when I try to drag-and-drop an open file from monitor 1 to monitor 2.  Transfer from one monitor to another works fine on all other applications (.pdf, .docx, web stuff, graphic files like .png, and .xlsx.  Only .mw files distort when I try to open them or move them to monitor 2.  I was able to move, open, etc. any .mw file for over a year, then a couple of days ago the files started to distort.  I had a 32-bit version of Maple (Maple 2015.2 build ID 1097895—deleted it.  Also deleted and reinstalled Maple 2015.0, build 1022128.  I checked and updated my video card, updated the 2-monitor settings on Windows 7.  All this to no avail, the Maple 2015.0 program works on monitor 1, but it can not be opened or dragged-and-dropped to monitor 2.

Help, advice, suggestions welcomed—many thanks in advance.

Les

See WA30 attached.  Why the error?  The variable that represents the vector is in vector form.  If I need to change this to THAXexa := ([1988.0, 1989.0, 1990.0 , ... etc], datatype=float, is there an easy way to convert the THAXexa matrix?

Thanks, Les  WA30.mw

In Maple 2015 is there a way to fit data to an exponential model and determine the goodness of fit?

Thanks in advance!

Les

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.

dear all,

I have a problem when I try to find points on boundary of the surface.

the surface ploted from a matrix as follow:

please help me to generate a bondary curve of this surface.

Thanks

Hi, everybody.

I have a problem when I try to plot3d a sub-surface from a surface as follows:

Download sub-surface.mw

sub-surface.mw

Please help me!

Thanks and have a nice day.

What is the Maple Formula for the Excel function: =WEIBULL.DIST(A1,2,6.2,FALSE)

where A1..A26 is 0..26  ?  How do I plot it?

Thank you, Les