Hi everyone,

I have a question regarding the simplification of an equation. Suppose I have and equation in maple such as (4*y^2 + 8*y + 8*sin(y))/(y^2 +1)=0. Is there a sequence of commands in Maple to simpliy this equation to (1/2)y^2 + y + sin(y)=0?

I know mulitplying the entire original equation by (1/8)*(y^2+1) would achieve the objective, but the equations I am generating are much longer and more complicated. The example above was chosen just to illustrate the goal.

Best,

Justin

Hello Maple-Primers!

I am trying to evaluate a system at many different points.  I would like to include an interpolation function in this system, but have thusfar been unsuccessful.

Usually, I solve a system symbolically by using eliminate and unapply:

eq[1] := A = M^3;
eq[2] := C = A*2;
eq[3] := D = N+3;
eq[4] := B = piecewise(A = 0, 0,C);
eq[5] := E = B*D;
elimsol:=eliminate(convert(eq,list),[A,B,C,D,E])[1];

unappsol:=unapply(elimsol,[N,M]);

unappsol(1,2);
{A = 8, B = 16, C = 16, D = 4, E = 64} <--- great!

Now, I want to include an interpolation function in the system of equations.  They look like this (see worksheet for actual interpolation function):

B_interp := (W,T) -> CurveFitting:-ArrayInterpolation([FC_Map_W,FC_Map_T],FC_Map,Array(1 .. 1, 1 .. 1, 1 .. 2, [[[W, T]]]),method=linear);

eq[5] := E = B_interp(N,M);

Error, (in CurveFitting:-ArrayInterpolation) invalid input: coordinates of xvalues must be of type numeric <-- bad!

Anyone have any ideas?  I've tried to use polynomials, but I can't seem to get a fit close enough for my purposes.

Maple_2D_Interpolate_FC.mw

A (probably) stupid question that is driving me crazy: how can I expand in Taylor series the following potential function

f(r_):=Int(Int(Int(G(r_-r0_)-(x_-r0_)*rho(r_))))?

essentially the Green representation formula for a harmonic function f in the whole 3d space.

Thanks in advance!

solve([x + 3*y + 5*z = 0,
7*x + 9*y + 11*z = 0,
13*x + 15*y + 17*z = 0],[x,y]);

Hi guys,

I'm trying to find the solutions to a nonlinear equation system:

mysol := solve({J*a = m*g*l*st-m*l*(c*cp*st+d*sp*st), cx*ux = cMx*xd+(Mx+m)*c+m*l*(-cp*pd^2*st-cp*st*td^2-2*ct*pd*sp*td+a*cp*ct-b*sp*st), cy*uy = cMy*yd+(My+m)*d+m*l*(2*cp*ct*pd*td-pd^2*sp*st-sp*st*td^2+a*ct*sp+b*cp*st), (-M*l^2*st^2+J)*b = m*l*sqrt(d^2-2*d*ct+ct^2+c^2*ct^2+(c^2*sp^2-2*c*cp*d*sp+cp^2*d^2)*st^2)}, {a, b, c, d})

The solution contains various implicit solutions with RootOf's. When trying to evaluate them by typing

allvalues(mysol);,

the returned set of solutions is about 800.000 characters long, but unfortunately contains various "+ [...15295 terms...] +" elements, and thus not displaying the full solution. The limits on the precision tab in the maple options are all disabled.
Does anybody know how to display the full expression, although it gets very long?

Thank you in advance,

Martin

Hi everyone,

I'm running Maple 18 and MapleSim 6.4 on my macbook pro 13 " with retina display and the GUI is blurred like there is no smoothing or the antialiasing is not working properly. I tried to find something helpfull in the setting but with no luck.

Is there something I can do to fix this?

Thanks

Carlo

Whenever I use the function changevar() and press ENTER, I always get the following output, despite paying

attention to the syntax

example:

g1:=changevar(q,g,t);

Output:

g1:=changevar(....)

Ideally, I would like the output to be the following:

g1:=...

What could be the problem with my code?

U

got an error when try to jacobian this

with(VectorCalculus):
f1 := -2*x1-x2; f2 := -x1-4*x2; g1 := 2*x1+3*x2-6; g2 := -x1; g3 := -x2;
penalty := lambda1*max(f1-M,0) + lambda2*max(f2-M,0) + (M^2)*(max(g1,0) + max(g2,0) + max(g3,0)):
obj := eval(penalty,[lambda1=3,lambda2=0.645,M=1]);
Hf := Jacobian(Jacobian(obj, [x1, x2, x3]), [x1, x2, x3]);

Error, invalid input: VectorCalculus:-Jacobian expects its 1st argument, f,
to be of type {Vector(algebraic), list(algebraic)}, but received 3*max(0, -2*x1-x2-1)+.645*max(0, -x1-4*x2-1)+max(0, 2*x1+3*x2-6)+max(0, -x1)+max(0, -x2)

Hello,

       How long can I expect Maple17 to take to algebraically solve a system of 14 nonlinear equations that has approximately 40% nonlinearity in its terms? I am running it on the machine right now, but have no idea what to expect. As mentioned before, I'm new to Maple...

Here is my code:

restart; eq1 := A*z-B*a*z-V*a*q-W*(b+d)*a = 0; eq2 := W*(b+d)*a-V*b*q-(F*G+B+D)*b*z = 0; eq3 := V*a*q-W*c*(b+d)-(B+C+E)*c*z = 0; eq4 := V*b*q+W*(b+d)*c-(B+C+D+F)*d*z = 0; eq5 := G*F*b*z-V*q*e-(B+H)*e*z = 0; eq6 := H*e*z-V*q*f-(B+S)*f*z = 0; eq7 := S*f*z-V*q*g-B*g*z = 0; eq8 := V*q*g+S*s*z-(B+C+E)*h*z = 0; eq9 := F*d*z+V*q*e-(B+C+H+T)*t*z = 0; eq10 := H*t*z+V*q*f-(U+B+C+2*S)*s*z = 0; eq11 := T*t*z-(B+H+Y)*u*z = 0; eq12 := U*s*z-(B+S)*v*z+H*u*z-Y*H*v*z/(H+S) = 0; eq13 := g-c-d-t-s-h = 0; eq14 := z-a-b-c-d-e-f-g-h-s-t-u-v = 0; soln := solve({eq1, eq10, eq11, eq12, eq13, eq14, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9}, {a, b, c, d, e, f, g, h, q, s, t, u, v, z});

Thanks.

Greetings,

       I am new to Maple and this forum. I would like to obtain a Jacobian of a system of 12 ODEs. What have I done wrongly with my code?

eq_1 := -B*a+A-V*(c+d+t+s+h)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-W*(b+d)*a/(a+b+c+d+e+f+g+h+s+t+u+v);
eq_2 := W*(b+d)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-V*(c+d+t+s+h)*b/(a+b+c+d+e+f+g+h+s+t+u+v)-(F*G+B+D)*b;
eq_3 := V*(c+d+t+s+h)*a/(a+b+c+d+e+f+g+h+s+t+u+v)-W*(b+d)*c/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+E+C)*c;
eq_4 := V*(c+d+t+s+h)*b/(a+b+c+d+e+f+g+h+s+t+u+v)+W*(b+d)*c/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+C+D+F)*d;
eq_5 := G*F*b-V*(c+d+t+s+h)*e/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+H)*e;
eq_6 := H*e-V*(c+d+t+s+h)*f/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+S)*f;
eq_7 := S*f-V*(c+d+t+s+h)*g/(a+b+c+d+e+f+g+h+s+t+u+v)-B*g;
eq_8 := V*(c+d+t+s+h)*g/(a+b+c+d+e+f+g+h+s+t+u+v)+S*s-(B+E+C)*h;
eq_9 := F*d+V*(c+d+t+s+h)*e/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+C+H+T)*t;
eq_10 := H*t+V*(c+d+t+s+h)*f/(a+b+c+d+e+f+g+h+s+t+u+v)-(U+B+C+S+S)*s;
eq_11 := T*t+W*(b+d)*x/(a+b+c+d+e+f+g+h+s+t+u+v)-(B+H+Y)*u;
eq_12 := U*s-(B+S)*v+H*u-Y*H*v/(H+S);
with(linalg);
J := Jacobian([eq_1, eq_2, eq_3, eq_4, eq_5, eq_6, eq_7, eq_8, eq_9, eq_10, eq_11, eq_12], [a, b, c, d, e, f, g, h, s, t, u, v]);

I am getting the message: 

 Vector(4, {(1) = ` 12 x 12 `*Matrix, (2) = `Data Type: `*anything, (3) = `Storage: `*rectangular, (4) = `Order: `*Fortran_order})

Thanks!!

I have a rank 1 array M of 1000 values.

I want to apply a function f on each value of M and its location giving,

[f(1,M[1]), f(2,M[2]), ... , f(1000,M[1000])]

is it possible to get this using map or map2 or map[n] or maptype (without using seq since its slowing down computation).

inotherwords can i access the member location inside a map evaluation?

Hey,

I wish to find the zero crossing of the following eq. (with respect to x)

a is typically 1.729, b is 1.139 and c is 0.0688. Ploting the eq. and using the solve command result in two values (zero crossings) when replacing the constants by their respective values, but when I wish to have the solution with respect to the constants a, b and c the result is only for one of them. Any commands that can be helpful in this situation?

Thanks in advance.

Hello,

       I am new to this forum. I have typed the follwing code in Maple17:

restart; eq1 := A-B*a-V*a*q/z-W*(b+d)*a/z = 0; eq2 := W*(b+d)*a/z-V*b*q/z-(F*G+B+D)*b = 0; eq3 := V*a*q/z-W*c(b+d)/z-(B+C+E)*c = 0; eq4 := V*b*q/z+W*(b+d)*c/z-(B+C+D+F)*d = 0; eq5 := G*F*b-V*q*e/z-(B+H)*e = 0; eq6 := H*e-V*q*f/z-(B+S)*f = 0; eq7 := S*f-V*q*g/z-B*g = 0; eq8 := V*q*g/z+S*s-(B+C+E)*h = 0; eq9 := F*d+V*q*e/z-(B+C+H+T)*t = 0; eq10 := H*t+V*q*f/z-(U+B+C+2*S)*s = 0; eq11 := T*t+W*(b+d)*x/z-(B+H+Y)*u = 0; eq12 := U*s-(B+S)*v+H*u-Y*H*v/(H+S) = 0; eq13 := g-c-d-t-s-h = 0; eq14 := z-a-b-c-d-e-f-g-h-s-t-u-v = 0; soln := solve({eq1, eq10, eq11, eq12, eq13, eq14, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9}, {a, b, c, d, e, f, g, h, q, s, t, u, v, z});

This is to symbolically solve a nonlinear system of (14) equations. But when I press Enter, it just returns the message "Ready". Shouldn't it say "Evaluating"?

I don't see anything syntactically wrong with my code...

Hello there!

There seems to be an issue with indexed variables and the instruction "DGsetup" of the differential geometry package when used with Maple 17. An error is returned to the effect that DGsetup is expecting independent variables to be unassigned names. This phenomenon does not occur with Maple 16!

Here is what I get:

> restart;
> with(DifferentialGeometry); with(Tools); with(Tensor); with(LinearAlgebra);

Executing the following command, I get an error with Maple 17 which does not occur with Maple 16!

> DGsetup([seq(x[i], i = 1 .. 4)], M, verbose);
Error, (in DifferentialGeometry:-DGsetup) expected 1st independent variable to be an unassigned name, received: x[1]

Is there any fix for this problem?

Kind regards
Freddy Baudine

See below for an example. The units in this formula cancel out. Instead I observe this behavior (not just in this case, ALWAYS): The units just keep piling up to an unmanageable pile. That's why I gave up on including units entirely, I end up with 5% (of total screenspace for the entire result) for the numeric part and 95% for the bloated unit result.

How do I get Maple to process the units and not just carry them? I know it can do it, after all, sometimes it does. I just can't see the system.