equation 1 : x_i+1=x_i− (f·g_y−f_y·g)/(f_x ·g_y −f_y ·g_x)
equation 2: y_i+1=y_i− (fx·g−f·g_x)/(f_x·g_y-f_y·g_x)

My quesiton are, deriving equations (1) and (2) above and constructing a single Maple function called newt2d that implements both of these recurrence relation.

I apolgize in advance if I don't write my question correctly.  This is my first time posting a question. 

i wrote this problem to solve 

Delta= Sum(j=1 to n)SUM(i=j to n)(pi*hj/Ad(t,ij)*Et,ij))

Where n=70,  G= ftj (t)/(4+0.85*t) , where (t =8, 16, 24,…….up to 8*n), hj= 13 for all j except j1 =18

Ad= (Aj+s(mij-1)), where Aj varies

Mij=ES/E(G),          where E(G)= 57sqrt(1000*G)

Download short.mw

Hi All,

I have a fucntion f(x,y,z) = exp(-x^2 -y^2 - z^4) and would like to plot the probabity density in real space. One method would be to randomly sample points in a grid based on f(x,y,z). The function f(x,y,z) is clearly peaked around x=y=z=0, so you would expect many points to lie around there. So the plot would look like a clump near (0,0,0) which gets less dense away from (0,0,0).

In the worksheet below, I sampled points from the Uniform distribution to file in the 3d-plot. I would like these points to be sampled from f instead, but am not sure how to do this.

Any help is appreciated,

Download Sample_Test.m

I have the following code in Maple 13:

SYS := {diff(T(x, t), t) = diff(T(x, t), x, x)};
IBC := {T(1, t) = 0, T(x, 0) = 1, (D[1](T))(0, t) = -exp(t)};
SOL := pdsolve(SYS, IBC, numeric, time = t, timestep = 1/10);
R := SOL:-value(output = listprocedure); temperature := subs(R, T(x, t));

It integrates the heat equation in the interval x=0..1 and it seems to work ok.
However, I have problems trying to obtain the temperature derivative at the boundaries (this is at x=0 and x=1). I'm using different commands and it seems the derivative is evaluated ok inside the domain but not at the boundaries.
If I try
fdiff(temperature(x, t), [x], {x = 1,t=0.5});

or

evalf((D[1](temperature))(1, .5));

I don't get any numerical answer. Any idea how I could obtain the value of the derivative at the boundaries?

Thanks in advance,

Javier

When I write an conditional command I come back and press enter again and again but I need only last one for example 

>f:=x->x^2+x+1

>g:=y->y^2+2*y+6

>x:=0;y:=0

>if f(x) <g(x) then;

>x:=x+1 elif f(x) >g(x) then;

>y:=y+1 elif f(x)=g(x) then;

>x;

>y;

>f(x) end if;

I push enter and it write x:=1 then I click if command and push enter again and it writes x:=2 and continues like y:=1, x:=3, y:=2, x:=4,  y:=3 and lastly 

4

3

21

But I only need last one. Can I do this only push enter once. Of course my problem is more complicated than this f(x) , g(x) . Thanks

Hi!

Is there any possibility for taking the negative sign outside a function, like factorization of -1?

Say I have. 

,

How do i get this output?

Thanks!

> restart;

with(plots);

pr := .72; p := 0; n := [.5, 1, 1.5]; s := 0; a := .2; b := 0; L := [red, blue, green]; l := 0; k := 1;

for j to nops(n) do R1 := 2*n[j]/(1+n[j]); R2 := 2*p/(1+n);

sol1 := dsolve([diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))+R1*(1-(diff(f(eta), eta))^2) = 0, diff(diff(theta(eta), eta), eta)+pr*k*f(eta)*(diff(theta(eta), eta))+R2*pr*k*(diff(f(eta), eta))*theta(eta)+(2*(a*(diff(f(eta), eta))+b*theta(eta)))/(1+n[j]) = 0, f(0) = 1, (D(f))(0) = b*((D@@2)(f))(0), (D(f))(1.8) = 0, theta(0) = 1+s*(D(theta))(0), theta(1.8) = 1], numeric, method = bvp);

fplt[j] := plots[odeplot](sol1, [eta, diff(diff(f(eta), eta), eta)], color = L[j], axes = boxed); tplt[j] := plots[odeplot](sol1, [[eta, theta(eta)]], color = L[j], axes = normal) end do; plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(tplt[j], j = 1 .. nops(n))]);

staganation_point1.mw
 

can we chage the axis sir ?? like  f'' vs eta to f'' vs lambda.

Download staganation_point1.mw

dear all,

how can I plot

 u:=(3*x-1)*(1-x):
v:=2*x*(1-2*x):

in (u,v)-plane

where x from 0..1

Hi !

This is my code : Ass2.mw

and I don't know why I have this warning : Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)

and I can't plot my curve after :) If you guys have any ideas... thank you!

Hello everyone,

I am trying to solve a system of ODE's numerically but the problem is with the condition f(0)+g(0)=1.

Here is the system with the initial conditions,

restart:
ode1:=diff(f(x), x,x)+(f(x)+g(x))*diff(f(x),x)=0;
ode2:=diff(g(x), x,x)+(f(x)+g(x))*diff(g(x),x)=0;
ics:=f(0)+g(0)=1,D(f)(0) =0,D(g)(0) =1;
dsolve({ode1,ode2,ics},numeric);

which give an error

Error, (in DEtools/convertsys) invalid specification of initial conditions

The above system is a simplified form of a very complicated one.

Hi Maple expert,

May I ask your time little bit, I am struggling with the 3D plot in maple, for basic 3D plot in maple is no problem for me, but this is a new case for me actually I want to perform a 3D plot based on these 3 different type of plots (or equations), here they are:

1. plot(2*(exp(-0.15*(u)^1.5))*(u)^0.5,u=0..2);

2. plot([0.2*(x-sin(x)),0.5*(1-cos(x)),x=0..10*Pi]);

3. polarplot(4+1*cos(5*x),x=0..2*Pi);

Can someone help me for this, many thanks for your help and time.

http://www.sciencedirect.com/science/article/pii/S100757041300508X> restart;
> l := 1; p := 1; A := .5; B := .5; pr := 1; n := [.5, 1, 1.5]; M := 0; b := .5; L := 0; s := .5; K := [blue, green];
                                      1
                                [0.5, 1, 1.5]
                                [blue, green]
> 
> for j to nops(n) do R1 := 2*n[j]/(n[j]+1); R2 := 2*p/(n[j]+1); R3 := 2/(n[j]+1);

sol1 := dsolve([diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))+R1*(1-(diff(f(eta), eta))^2)-M*(diff(f(eta), eta)) = 0, diff(diff(theta(eta), eta), eta)+pr*f(eta)*(diff(theta(eta), eta))-R2*pr*(diff(f(eta), eta))*theta(eta)+R3*(A*(diff(f(eta), eta))+B*theta(eta)) = 0, f(0) = 1, (D(f))(0) = L+b*((D@@2)(f))(0), (D(f))(7) = 1, theta(0) = 1+s*(D(theta))(0), theta(7) = 0], numeric, method = bvp);

plots[odeplot](sol1, [eta, ((D@@2)(f))(eta)], color = red);

fplt[j] := plots[odeplot](sol1, [eta, diff(diff(f(eta), eta), eta)], color = K[j], axes = boxed); fplt[j] := plots[odeplot](sol1, [eta, f(eta)], color = K[j], axes = boxed);

tplt[j] := plots[odeplot](sol1, [[eta, theta(eta)]], color = K[j], axes = normal) end do;

plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(tplt[j], j = 1 .. nops(n))]);
http://www.sciencedirect.com/science/article/pii/S100757041300508X

Dear sir 

I am trying to plot the following link paper graphs for practice but I getting the plots for only one set of values here in this paper they plotted many so if you dont muned can help in this case. For example in this first graph named as Fig.1. please can you do this favour... and the paper link is  http://www.sciencedirect.com/science/article/pii/S100757041300508X

If I want to clear the screen what command I must use?

Thank you

Hi

I have a maple file (saved as a workbook) which is saved in dropbox and has been saved during progress.  However, when I open the last version in maple, it opens a version which looks like it is some of the first versions. I have tried following things without success:

* Restore previous versions from dropbox and open them in maple.  No matter which version I open, it shows the same two lines of text.  In dropbox I can see all previous versions and their file size which all are different and increasing in size over time as more was added to the file.

* send the file to another computer and open in maple on that computer

Does anybody have the answer to what I can do/what the problem is?

Thanks!

/Katie

Hello every one,

I'm using Maple to create a compiled program of my model Maplesim. I had a error with "getcompiledProc" command, which is :

Error, (in GetCompiledProc) non-numeric initial condition for `Main.RAB.value`(t): Float(undefined)

the "Main.RAB.value(t)" represent a probe used to visualize an output of my system.

Does anybody had a such error ?
Thank you for your responses.

Larbi ANIBA