Hi folks,

I've come across this project which involves large algebraic expressions and I need to be able to simplify it using Maples in-built features, but with no succes.

The problem involves trig-functions. For instance I have several expressions involving:

       cos(v)*sin(w)-cos(w)*sin(v)       which I know equals     -sin(v-w)

but even if I use simplify, trig, size and so on it won't apply the above identity. Btw there are several other identities that aren't applied either.

Is there any way to "force" the above identity into consideration??

how to use Riemann matrix to output Riemann surface?

and plot this surface?

with(algcurves):
f:=y^3+2*x^7-x^3*y;
pm:=periodmatrix(f,x,y);
evalf(pm, 5);
rm:=evalf(periodmatrix(f,x,y,Riemann),10);
M := rm;
A := proc (x, y) options operator, arrow; RiemannTheta([x, y], M, [], 0.1e-1, output = list)[2] end proc;
plot3d(Re(A(x+I*y, 0)), x = 0 .. 1, y = 0 .. 4, grid = [40, 40]);

is this graph Riemann Surface?

if so, how to convert A into polynomials?

Please help me solve this question using maple (need the steps in solving).

When I copy mathml into Maple it always pasted the subscipts as indexed.  How could I quickly convert the indexed subscripts into literal subscripts without having to right click and convert each variable?

What is the best way to export/update multiple values from a single procedure? As far as I understand, a procedure does not let you update global values (the inputs), and it returns the value for the last step performed. Let's say for example, I had a procedure like this:

proc(a,b,c)

local x,y;

*series of steps that use a,b, and c to calculate x and y*

end proc

How do I get the results for x and y out of the procedure? 

Thanks

So I have an integral that computes perfectly in wolfram alpha but not in maple...

I will post it here

int(1/((4.532055545*10^9/f^4.14-2.311250000*10^5/f^2+(111*(1-0.2163331531e-4*f^2+2.340001656*10^(-10)*f^4))/(1+0.1081665766e-4*f^2)))*(6*10^(-21)*abs(1/f^(4/3)))^2, [f = 50 .. 1500])

the answer should be 3.05364*10^-46

If you try that exact line of code in maple, it will not compute (is stuck on evaluating)


Best Regards to all,
Zeus

I'm displaying a series of point plots as an animation, and would like to update a displayed parameter as well.  I have a nested list L[t] where there's a set of points for each t, and for each t there's also a numerical value M that I'd like to display.  (In my real problem, L[t] is the number of particles in each of several states, and M is the rms deviation from am algebraic probability distribution.)  

The closest I've gotten (for a simple L and M) is the following, but it displays all of the M values in the legend at once:

with(plots); with(Statistics);

L := [[1, 2, 3, 4, 5, 6], [2, 4, 6, 8, 10, 12]];

M := [1, 2];

display([seq(PointPlot(L[t], legend = M[t]), t = 1 .. 2)], insequence = true)

I don't need this to be in the legend.  Is there a way to display only the current value of M for each t?  Thanks very much.

How to prove or disprove the flatness of the surface x = (u-v)^2, y =  u^2-3*v^2, z = (1/2)*v*(u-2*v), where u and v are real-valued parameters? Here is my try:

I think Gaussian curvature should be used to this end. Dr. Robert J. Lopez is my hope.

Download flat.mw

I've been trying to make a smooth plot of some ODEs. It should show C rapidly increasing at the innitiation, until they get into a quassi steady state,  and then all three variables increase much slower. This should look like a roughly straight line that elbows sharply into a smooth curve.

Any attempt to DEplot3d it i've made either just shows the time before the quassi steady state is reached, so shows the straight line; or smooths that time together with the next period, making the straight line look like a part of the smooth curve.

Model := [diff(B[1](t), t) = k[a1]*C(t)*(R-B[1](t)-B[2](t))-k[d1]*B[1](t), diff(B[2](t), t) = k[a2]*C(t)*(R-B[1](t)-B[2](t))-k[d2]*B[2](t), diff(C(t), t) = (-(k[a1]+k[a2])*C(t)*(R-B[1](t)-B[2](t))+k[d1]*B[1]+k[d2]*B[2](t)+k[m]*((I)(t)-C(t)))/h];
DissMod := subs((I)(t) = 0, Model);
AssMod := subs((I)(t) = C[T], Model);


Pars := [k[a1] = 6*10^(-4), k[d1] = 7*10^(-3), k[a2] = 5*10^(-4), k[d2] = 10^(-2), R = .5, k[m] = 10^(-4), C[T] = 100, h = 10^(-6)]

StateSol := DEplot3d(subs(Pars, AssMod), [B[1](t), B[2](t), C(t)], t = 0 .. 1000, number = 3, B[1] = 0 .. .5, B[2] = 0 .. .5, [[B[1](0) = 0, B[2](0) = 0, C(0) = 0]], scene = [B[1](t), B[2](t), C(t)], maxstep = .1, maxfun = 0, method = l)

Is there a way to display the list of coordinates for implicitplot and plot, rather than the displaying image itself?

In Maple Classic this happens automatically when the assignment operator is used  ( := ) together with a semi-colon, eg.   A:=implicitplot(F, x=-1..1, y=-1..1);

But is there a way to do this in the non-classic version?  Thanks very much.

- Graham

Hello fellow maple struglers!

This is my first question, so hopefully I did it in the correct manner. My problem (I think) is of a simple nature, but I can't seem to get it to work. The equation I have is the following:

All is nice and well and as you all can see it depends on two variables. Now what I want to do is to express the function in a shape where it depends on the ratio t/d only. Simple calculus shows that for this equation it is rather easy, where the result is:

(62,8*t/d+0,0945)/pi

Now I would like to know whether it is possible to automate this in maple, such that I can plot Wr_over_p as a function of t/d. I know I can simply use the form above and make the plot, but further down in my maple file I have an equation which is much more complex, and I want to plot thatone as a function of t/d as well.

I hope I have made my problem clear to some of you guys, but if you require some further explaination than please let me know. Thanks in advance for your help, I hope there is someone who can help me with this!

I have two deformed planes, that i would like to draw with 3dplot, as well as drawing a curve marking their intersection.

the curves are given by the expressions:

C = -(k[d2]*B[2]+I*k[m]+k[d1]*B[1])/((B[1]+B[2]-R)*k[a1]+(B[1]+B[2]-R)*k[a2]-k[m]),

C = k[d1]*B[1]/(k[a1]*(R-B[1]-B[2]))

evaluated at

Pars := [k[a1] = 6*10^(-4), k[d1] = 7*10^(-3), k[a2] = 5*10^(-4), k[d2] = 10^(-2), R = .5, k[m] = 10^(-4), C[T] = 100, h = 10^(-6)]

with the variables B[1],B[2] and C within the bounds [0..0.5],[0..0.5],[0..100].

My method was to try and use solve to find a formula for the intersection curve- but i couldn't get 3dplot to plot it!

Consider the following code snippet:

with(DifferentialGeometry):
DGsetup([x],M);
RemoveFrame(M);

By itself it is, of course, pretty meaningless, but that is not the point. My problem is that after Maple has executed it, it will annoyingly continue using M> for each new execution group that is inserted. Having removed the frame with the command RemoveFrame, I would have expected that not to be the case. How can the frame be truly removed?

hi. i have a system of ODEs. is there any answer ? rho is constant !

Download dsolve.mw