restart; with(DEtools) x1 := diff(x(t), t) = (4-x-4*y)*x; y1 := diff(y(t), t) = (4-4*x-y)*y; phaseportrait([diff(x(t), t) = (4-x-4*y)*x, diff(y(t), t) = (4-4*x-y)*y], [x(t), y(t)], x = -20 .. 20, y = -20 .. 20, t = -2 .. 2, [[x(0) = 0, y(0) = 1]], stepsize = 0.5e-1, scene = [y(t), x(t)], linecolour = sin((1/2)*t*Pi), method = classical[foreuler]) I'm trying to specify the domain for x and y but I receive the following error Error, (in DEtools/phaseportrait) initial conditions must be specified in inits The above works when I get rid of x = -20 .. 20, y = -20 .. 20,

 How do I get both branches (i.e. positive and negative values) for f(x) on the same plot of f(x) = x^(1/2)?

 

Thanks very much,

Greg

Hi,

I have a frustrating error that comes from using Code generation with diff

It works fine when processing a single equation but doesn't like matricies:

> Xx := ((cos(q1)*cos(q2)+0.8e-3*sin(q1)*sin(q2))*sin(q3)+(0.8e-3*(-cos(q1)*sin(q2)+0.8e-3*sin(q1)*cos(q2)))*cos(q3)+sin(q1)*cos(q3))*L3+(0.8e-3*(cos(q1)*sin(q2)-0.8e-3*sin(q1)*cos(q2)+0.8e-3*sin(q1)))*L3+sin(q1)*(L21+L22);

I would like to calculate engineering stress using array; but the following piece of codes do not seem to work. *EngineeringStress = force / area *Define force is an array of measurements of force. crossArea:= 3.2 * 19.1 (not the "*" is really a "." in Maple editor; it is multiplication) force := array ([0., 1380.0, 2780.0, 5630.0]) engineeringStress := force/crossArea; engineeringStress[1] ({0., 1380.0, 2780.0, 5630.0}/crossArea)[1] it suppose to be 0!!!

When i input something like sqrt(30) I just get back 30 with a square root symbol over it. How can I make maple evaluate it?

How do I generate a gaussian random matrix (2x2).

Is this the default setting already in maple or is there code I need to use?

I'm to generate a random matrix ie > with(LinearAlgebra); > RandomMatrix(2, 2, generator = -1 .. 1); and find the eigenvalues of each matrix ten times. How do I put random Matrix in the for loop with Maple?

I have two vector here

X:= vector([-1,0,1])

Y:=vector([1+I*2,3+I,4+3*I], datatype=complex)

I want to fit them in the form a*exp(-I*10*t)+b*exp(I*10*t), a and b may be complex.

How should I do?

I have two vector here, and I want to fit them with the form a*exp(-I*4375*t)+b*exp(I*4375*t), a and b should be complex. How should I do?

X := Vector([-0.000163, 0, 0.000163], datatype = complex);

Y := Vector([-8.84352*10^(-13)+(I*1.71511)*10^(-12), 1.49867*10^(-13)+(I*1.45355)*10^(-12), 1.15763*10^(-12)+(I*9.08261)*10^(-13)], datatype = complex[8]);
 

 

Dear all,

I am trying to built in 3d function of recurrence relation

V(i)=a*V(i-1)-V(i-2); a=const; initial conditions: V(i-1)=-1; V(i-2)=-2.

An axes of a three-dimensional surface have to be: V(i); V(i-1); i.

I created these two procedures, I want to introduce within a mla.
 But I have the following two problems that I need you guys help me 
solve:

Hi, I want to build recursively defined, piecewise functions.

I first defined my zero-order functions

N40(xi)=piecewise(0<xi and xi<=1);

N50(xi)=piecewise(1<xi and xi<=2);

and I can plot them with desired result

but, how do I combine them, to make first order functions?

 for instance, I want to have a function matematichally defined by:

N41 = (xi-1)*N40 + (2-xi)*N51

 

Hi all,

I've searched all over, and I can't figure this out: I'm hoping to have a result expressed in symbolic notation.  For example, if my result is x_1+x_2+...+x_n, how can I have maple express this answer as summation of x_i i=1 to n.

I actually have a matrix, each element of which is a ratio of summations.  In order to more easily comprehend it, I'm hoping to view it in summation notation.

 

Thanks,

 

Paul Burkander

So far I have a circle with a cornu spiral joining where their curvatures are equal as below.

S1:=unapply(u*FresnelS(u)+((1/Pi)*cos((1/2)*Pi*u^2))-(1/Pi),u);

C1:=unapply(u*FresnelC(u)-((1/Pi)*sin((1/2)*Pi*u^2)),u);

R1:=1;

u1:=evalf(sqrt(0.4));

E1:=evalf(Pi*R1*S1(u1)+R1);

D1:=evalf(Pi*R1*C1(u1));

with(plottools);

with(plots);

c1 := circle([D1, E1], R1);

display(c1);

a:=evalf(Pi*R1*u1);

I am trying to use the output of an equation to set the value of a slider. In other words, how do I display the output of an equation in a slider / meter form ?