August 01 2007
MU 4
Hi,
I am new to Maple and am having trouble with what should be a simple task. I have a series of simultaneoous equations of the form a*x+b*y=c etc. I have found an initial equilibrium by choosing values of x and y which give me reasonable values of a and b (using the Solve command I have output of a,b,c,x,y which satisfy my equations).
Now, I need to use the parameters I have, my a,b,c, to try and retrieve my x and y (my real aim in this is to see the effect on the x,y when I change the a,b,c). When I try and put the equations plus parameter values into Solve it takes a very long time to solve (I stop after 20mins). What I want to do is use the equilibrium values I obtained before to give Maple a starting point to search for a solution.

Hello!
I have some trouble with getting an explicit solution to a PDE:
f=f(u,v) in IC^4 (IC=complex numbers)
So i have a system of 8 equations, first order, integrable (i.e. solution exists by theory).
I'm getting the following, when calling pdsolve(PDE, fcns), where PDE is the set of the PDEs and fcns are the 4 complex functions f[i], i=1,2,3,4:
"Error, (in pdsolve/sys) duplicated elements (ranking)"
What could it be?
Thx,
yadaddy.

Hello,
This is related to my recent posts at
http://www.mapleprimes.com/forum/integral-equations#comment-8339
I have a function of three variables one of which is inside a (difficult) integral. I want to calculate & store the array of points which satisfy the function, then use transform to change those points and then plot them. The function looks like this:
P:=(x,m)->sqrt(x)/(sqrt((x+m)^2-1)*(x+m+sqrt((x+m)^2-1)));
IntegralP:=(m)->Int(P(x,m),x=0..infinity);
f4A:=(beta,Omega,m)->beta^2+(3*(beta*Omega)^(3/2)*evalf(IntegralP(m)))/(4*2^(3/4))-1;
In my earlier case, m=1 (and there was another variable, but it wasn't under the integral) so the integral was not a problem. I tried the same method;

Still being a newbie to Maple, I am stuck on this one. I am trying to create a general system of changing my equations in an [x,y] coordinate system to a [u,v] system.
As a specific example: I have two substitution equations, u=2x-3y and v=-x+y. I have four equations: x=0, x=-3, y=x, y=x+1. I have tried MapToBasis with both static and procedure statements and I am not having any luck. The equations do not completely change to [u,v]. Here is one example:
> proc (u, v) u = 2*x-3*y end proc;
> proc (u, v) v = -x+y end proc;
> with*VectorCalculus;
> SetCoordinates('cartesian', [u, v]);

I am trying to plot the equations shown in Figures 5 and 6, which are solutions to Equations (14), (15), and (16). These equations are developed in the Lo paper (attached). I am working through the symbolic solution by hand and would greatly appreciate any suggestions on how to set these equations and the graphs of the same in a worksheet. Thank you for the assistance anyone may offer.
Wayne Bell

Download 4865_Lo_p691.pdfView file details
Download 4865_Lo_p692.pdfView file details
I am trying to convert equations from cartesian to polar and spherical expecting Maple to change the variables from x,y and z to r, theta, etc. I presume I am using the wrong commands.
convert(exp(sqrt(x^2+y^2)),polar)
returns the same expression in x and y. What is the correct command?
thanks

I seem to keep running into things in Maple that I just can't get to plot. I have been using Mathcad and am trying to learn to do everything in Maple, but keep finding myself having to go to Mathcad to do even the simplest things. Could someone please help and explain to me what I'm doing wrong?
I have with(plots) and restart() at the top of my page.
I then do this:
g1 := implicitplot(3x^2,x=0..10,y=0..10);
display( g1 );
This results in it just printing the display line again, no graph is shown.
I can get this to work using the plot command but since its not very easy in Maple to print multiple equations on a single graph I have started trying to do them this way. If there is a better way to do graphs then please tell me this as well as I'm trying to learn Maple as best as I can.

I would like to plot a projection using parametric equations:
x=la*cos(fi)
y=fi
fi=

This is to inform you that we are now shipping the newest version of Maple T.A. – Maple T.A. 3.0.
Maple T.A. is an easy-to-use web-based system for creating tests and assignments, automatically assessing student responses and performance. It supports complex, free-form entry of mathematical equations and intelligent evaluation of responses, making it ideal for mathematics, science, or any course that requires mathematics.
The new edition – Maple T.A. 3.0 – comes with increased flexibility in content creation, an enhanced user interface and improved grading and assessment capabilities

How do I parse the response string with Maple TA? I can make my code work just fine in Maple but that is assuming what type of string $response is. If someone has dealt with this before, I would appreciate some ideas. I am asking for three parametric equations and need to seperate them and use all three for determining validity of the answer.

Hello, I am doing some research with solar panels right now and I need to try and come up with equations for a multiple input single output system. What I am doing is taking numbers from a website and comparing to the actual numbers from solar panels I have set up in a field. But the head of the project is wanting to make some unique equations. I can easily do a single input single output by curve fitting or splining the information, but I have never tried a multiple input single output system. Is there a way to do this?
Chris

I'm completely new to maple, and I'm trying to solve some equations that have no algebraic solution but should be straightforward to solve with numerical methods. I'd be most grateful if anyone could offer some advice on how to do this.
For example, I'd like to solve the following two equations for p:
2^(1-p)+(1-x)^(1-p)/(1-p)
and
x^(2-p)-y^(2-p))/(x-y) = (a^(2-p)-b^(2-p))/(a-b)
The attached worksheet contains my unsuccessful attempts.

View 4985_equations.mw on MapleNet
I have a question which has three parametric equations as the answer. I then need to parse out variables from these equations and make sure the 3 equations satisfy 4 conditions. How do I have $response equal 3 different equations? My answer would be coming in as x=$a+$b*t, y=$c+$d*t, z=$f+$g*t.
I would then use the variables a-g in my tests.

Hi everyone!
(I'm Fench, hope my English isn't too bad).
I use Maple to solve non-linear differential equations using a numeric method, and I plot these solutions using the basic:
>slnew := dsolve({set1, set2, a1(0) = 0, a2(0) = 1, (D(a1))(0) = 0, (D(a2))(0) = 0}, {a1(t), a2(t)}, numeric);
>plot1 := odeplot(slnew, [t, a2(t)], t = 0 .. 10, numpoints = 10000);
So far it's ok. However, I'd like to compare the difference between the solutions when the initials conditions are slightly different, say, a2(0)=1.1 . So I use the same procedure to create a plot2, and I use:
>display(plot1,plot2);

I am running Maple 11 with a mac-intel MacBook (13'' screen). I have been running a procedure for plotting a system of differentail equations that depend on an arbitrary parameter. The procedure works well for some "simple" parameters. For some more complicated parameters, the memory count (bottom right hand size) goes from near zero to over 500 M in six seconds ! A message appears: "kernel connection lost", and warns that such problems could be due to firewall settings, but all my firewall software is off.
This procesure on these parameters works just fine with Maple 10 running in a PowerBook G4 (firewall connection also off).