Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

  Solving trigonometry Equations  sin^2(2x)-cos^2(8x)=0.5cos(10x)

Hello,

I have a question. I have to compare the times and steps taken by an algorithmus (which contents a loop).

So for time there is the time()-function, right? And is there any similar function for the steps taken?

So far i use a variable increasing by 1 each time, but i think there is an more elegant way to do it, which I just don't know.. :D

 

Thanks for any help!

 

Hello,

Good day.

How to avoid float(undefined) for v3, v4,v5 in this problem.

Thank you in advance.

Try_for_Second_Grade_Fluid.mw

Hi,

I am tring to  solve a set of boundary layer equations with boundary conditions using Runge kutta Felbergh 45. When I executed the file,  the following message appear " Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging". Can someone help me on this matter?

 

This is the simplest method to explain numerically solving an ODE, more precisely, an IVP.

Using the method, to get a fell for numerics as well as for the nature of IVPs, solve the IVP numerically with a PC, 10steps.

Graph the computed values and the solution curve on the same coordinate axes.

 

y'=(y-x)^2, y(0)=0 , h=0.1

Sol. y=x-tanh(x)

 

I don't know well maple. 

I study Advanced Engineering Math and using maple, but i am stopped in this test.

I want to know how solve this problem.

please teach me~ 

IT IS EULER's method

Hi,

 

I am new to Maple and have a problem when solving three equations with three variables. But when  I plug in into solve function then it gives no answer.

eqn1 := 24900 = A*exp(-X*1.293995859*10^22)+A*exp(-Y*1.293995859*10^22)+5852.27;

eqn2 := 6000 = A*exp(-X*1.293995859*10^22)+2422.929937;

eqn3 := 19100 = A*exp(-Y*1.293995859*10^22)+8275.199937;

Variables are [A,X,Y]

Hi there. I'm Student

i want to know how solve this problem.

please teach me! 

y'=(y-x)^2, y(0)=0, h=0.1

sol.y=x-tanh(x)

how solve this problem for maple? 

please teach me~

Hi!

I want to select 'Export using shapes for greater fidelity' under option, Export. But I can't find the tab ' Export to PDF-Format'. I'm using Maple 18 on a Mac-computer. 

Can anyone help?

Thanks

 

Esben 

Hello maple users,

I have 2 functions and each functions has 8 variables. I run a matlab code and get outputs for different values of these variables. I assumed 3 of them as constant because the combinations are too many. Anyway, I plot the results and I can see that one function is much better than the other. But I need to compare these functions mathematically. I need to show some proofs. Has anyone any idea what should I do? I wrote the functions on maple and take derivative with respect to one variable and try to see the reaction of the functions to that variable. i am confused.

 

Thanks

 

The details of the tasks are explained in the maple file attached but the aim is essentially to model the carbon cycle using first order diff eqs. I'm slightly confused as to how to exactly set up the equations for part a) and b). I've set up the required constants for the equations and the initial conditions as follows: 

#### initial conditions
atmos(0):=750;
bios(0):=600;
soil(0):=1500;


##### coefficients for rate of change
terrPhoto:=110/atmos(0);
terrResp:=110/bios(0);
plantDeath:=55/bios(0);
plantDecay:=55/soil(0);

and one of the equations as :

Diff(atmos(t),t):=terrPhoto*atmos(t); 

but I've been told that I would have to accommodate the direction of flow of carbon in the rates and also reconsider how many equations I would need.  hwk16.mw

Hello

I have some problem with " For loop". If i add more then one expression the, i recieve an error. Could you please help me to solve it? I have attached my file. Thank you.


restart 

with(ImageTools):NULL

with(FileTools):NULLNULL

Input Section

 

``

filelocation := "C:\\Users\\Mohammad\\Desktop\\ExerciseII\\1.jpg":

k := 3:``

 

zimage := Read(filelocation):

 

zwidth := Width(zimage):``

kernell := VectorCalculus:-`+`(VectorCalculus:-`*`(2, k), 1):NULLNULL

kerneld := `~`[`*`](Array(1 .. kernell, 1 .. kernell, 1), 1/kernell^2):

imheight := Height(zimage):NULL

imwidth := Width(zimage):````

Width(zimage, lower):

Width(zimage, upper):

View(zimage):NULL

new1zpic := Convolution(zimage, kerneld):

View(new1zpic)NULL``

aa := zimage(1 .. (), 1 .. (), 1):

bb := zimage(1 .. (), 1 .. (), 2):

cc := zimage(1 .. (), 1 .. (), 3):NULL

subimage := Matrix(VectorCalculus:-`+`(VectorCalculus:-`*`(2, k), 1), VectorCalculus:-`+`(VectorCalculus:-`*`(2, k), 1), 0):

newaa := aa:

"for i from k+1 to (RowDimension(aa)-k-1) do     for j from k+1 to (ColumnDimension(aa)-k-1) do     subimage:=aa(i-k..i+k,j-k..j+k).~kerneld     newaa(i,j):=add(add(subimage(m,n),m=1..(2 .k+1),n=1..(2*k+1))) end do; end do;"

Error, unterminated loop

"for i from k+1 to (RowDimension(aa)-k-1) do     for j from k+1 to (ColumnDimension(aa)-k-1) do  subimage:=aa(i-k..i+k,j-k..j+k).~kerneld    newaa(i,j):=add(add(subimage(m,n),m=1..(2 .k+1),n=1..(2*k+1))) end do; end do;"

 

 

``


Download pak2.mw

I have the following mathematical expression

where a=0.2, b=0.09, c=0.57, p=0.3 and q=1-p=0.7, Now i want to find the value of n for which the value of the expression will be 1, i.e., for what value of n , A_n will be 1?

Hej hej,

is there a way to obtain confidence intervals for the parameters in a NonlinearFit? To give you an impression of the problem which I was working on, I created a minimial working example (not sure wheather that actually helps). In this particular case, I have two parameters to fit the coefficients of a binomial series to some data I obtained. Beyond the values of the parameters (in a least square fit), I'm also interested in some kind of confidence interval, to get a feeling about how realiable my values are. Is there a direct (or even indirect) way to obtain such a thing. Either directly as a Maple function (confidenceintervals is not supported for NonlinearFit, if I'm not mistaken) or as something I can implement myself (within a reasonable time frame, as in hours rather than days).
Thanks in advance!

Cheer,

Sören

restart; with(plots); with(Statistics)

alpha[0] := 1.000000000:

m__max := 4:

model := Fit(pochhammer(z__1, m)*h__exp^m/factorial(m), [seq(m, m = 0 .. m__max)], [seq(alpha[m], m = 0 .. m__max)], m, output = [leastsquaresfunction, residuals], weights = [seq(1/abs(alpha[m]), m = 0 .. m__max)], iterationlimit = 10000)

model := [pochhammer(1.42349754368085, m)*16.2763580438677^m/factorial(m), Vector[row](5, {(1) = 0., (2) = -0.120508651249829e-1, (3) = 0.113910530162494e-1, (4) = 0.348907003220054e-3, (5) = -0.305508272150429e-2})]

(1)

plots[multiple](logplot, [{seq([m, alpha[m]], m = 0 .. m__max)}, style = point, color = black], [{seq([m, model[1]], m = 0 .. m__max)}])

 

``

Download nonlinearfit-problem.mw

Hi everyone,

at the suggestion of Carl I am making my question a post.

History:

Newbies often get fascinated with the power tower: x^x^x^...

The generalized power tower z^z^z^... is a special case of the Euler sequence:

z_{n+1}=c^z_n, for c\in C.

Like the Mandelbrot set: z_{n+1}=z^2-c, the power tower, often called infinite exponential, also has a general periodic map. It is included below and is taken from Daniel Geisler's site:
www.tetration.org

Shel and Thron proved that the infinite exponential conveges whenever c belongs to the red region, called today Shell-Thron region.

Definition of Julia Sets for the iterated exponential map:

Also like the Mandelbrot set, the infinite exponential admits Juila Sets. The Julia Sets of the infinite exponential however, are defined differently from the Julia Sets of the Mandelbrot set. They are defined to be  the closure of the periodic repellers of the Euler sequence . They are Cantor Bouquets.  Geisler's colored map then is a general map of how the corresponding Julia set behaves roughly, with c taken from the map. 

We can then introduce small cuts which go from the interior of the Shell-Thron region to the exterior, crossing at various angles, and this will tells us how the infinite exponential evolves. Generally speaking, each time one crosses the Shell-Thron boundary, one wittnesses what's called a Knaster explosion, wherein the exponential explodes into p subregions, where p is the pre-period of the multiplier.


When the parameter c exits the Shell-Thron region at angles of 2*Pi and Pi from the real axis (cuts right and left, p=1, 2), the infinite exponential either transitions from converging to a single feature to exploding into multiple indecomposable contiua (p=1), or it breaks into a period 2 bifurcation (p=2), which itself, also may explode into continua.

When it exits at angles 2*Pi/p, where p>2 is the preperiod of the multiplier, then the infinite exponential evolves from converging to a single feature, to exploding into  p major regions, called Fatou regions, each one having its own attractor, displaying a p-furcation.


In all cases,  the Knaster explosions may introduce the presence of indecomposable continua, as some Fatou regions end up covering entire parts of the complex plane after each transition. In the animations, Knaster explosions occur whenever the background is red. There may be more than one explosion present in the evolution of the power tower. 

Cantor Bouquets are strange creatures. They are essentially quantum sets, and no point of them is actually visible. The probability a point is visible varies directly with the area of the corresponding bouquet "finger" which is rendered in the area of interest. Devaney uses these "fingers"  to obtain "iteneraries" of the iterated exponential map.

Points "close"  to the fingers-hairs o the Cantor Bouquets escape towards complex infinity at (final) angles 2*Pi/p.

The "hairs" of a Cantor Bouquet are C^\infty curves, hence they can be termed easthetically pretty. Only hairs from the main Cantor bouquet for c=e^{1/e} are globally convex/concave. Every other bouquet may contain hairs which change curvature "unpredictably".

Inlcuded files:

1) Euler.mw

2) EulerAnimation.mw

3) EulerAnimation2_noaxes.mw

 

Code for static fractal with given parameters in 1). Parameters can be changed in the constant section (Try p=2,4 or Pi)

Code for morphing animations through cuts in the Shell-Thron region in 2). Parameters d1-d2, N

Code for zooming animations in 3). Parameters M, M1-M2,

Limitations:

Will show attractors of broken Fatou basins only up to pre-period p=5. No big deal though. If you want to increase the preperiod past p=5, you need to add the relavnt tests in procedure ppc(c), otherwise the new attractors are not calculated and the plot ends up red.

Colors are assigned a bit more dispersed, using ln(m). You can also use m in that place. It depends on which area you are in.

Basins of attraction and Fatou regions change appearance under different epsilons. If you want different shapes for the basins, you can try using the Manhattan metric in proc Jhf, instead of |z-lim|.

Included below are the main map of tetration by Daniel Geisler, a short excerpt of the Shell-Thron region which shows pre-periodic cuts and  6 morhing transitions, for p\in {1,2,3,4,5} and one which exits at the angle of 2 radians (p=Pi).

References:

More than 300. To be published with my thesis. Patches, problems and code corrections in the original question page:

http://www.mapleprimes.com/questions/203593-Maple-13-Fast-Maple-18-Crawling

Hello

Is there any option to create a vector with logaritmically spaced? somthing like "logspace" in matlab. (logspace(0:10:20))

Thank you.

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