Hi everyone:

I want to earn f(zeta) and zeta=x/a while the f(x) is: 

f:=(x)->A1*sin(k*x)+A2*cos(k*x)+A3*sinh(k*x)+A4*cosh(k*x)

zeta=x/a and a, k, A1..A4 are constants. 

f(zeta)=? 

Hello,

I have problem with usage of diff function. I need to compute partial derivative over   in that equation.

T__ln := (1/2)*(diff(varphi__l(t), t))^2+((1/2*(m))*v__l+(1/2*(I))*(diff(varphi__l(t), t))^2)+((1/2*(m))*v+(1/2*(I))*(diff(varphi__l(t), t))^2)

If I am trying to use:

diff(T__ln, diff(varphi__l(t), t))

I get the error:

Error, invalid input: diff received diff(varphi__l(t), t), which is not valid for its 2nd argument
 

Hi all, this is my first post here, I'm finding Maple super interesting so far.

I had a little problem with plots, whenever I update my underlying function and re-run my cells it won't update the curve at all whether automatically or after selecting the entry and pressing `execute ! `.

I'd have the select and delete the plot and then re-plot again.

Is this how it is or there is something I'm missing?

LeadingTerm(y^2-x^2/y, plex(x, y));
 

(in Groebner:-LeadingTerm) the input is not polynomial in, {x, y}

how to do when fraction in it ?

it return error

plot(x mod 3, x=-5..5);

plots exactly the same as

plot(x, x=-5..5);

and

plot(floor(x) mod 3, x=-5..5);

The mod function is doing nothing, why?

If I do 5 mod 4 I get 1, as expected.

n := 0
u[0] := x^3+(1/2)*A*x^2
for k from 0 to n do
A[k] := sum((Diff(u[i], x))*(Diff(u[k-i], x)), i = 0 .. k);
A[k] := sum((diff(u[i], x))*(diff(u[k-i], x)), i = 0 .. k)
end do;
 

it gives A[0]:=0 which is incorrect. why? and how it will give correct answer?

Please simulate it geometricaly ?

FILM

Need the code of the following:

h is the step size could be 0.1 or 0.01 etc

Dear experts

I am trying to study linear version of the Navier-Stokes (NS) equation. I define NS equations in a way suggested in this page

restart;

with(PDEtools): with(Student[VectorCalculus]):

SetCoordinates(cartesian[x,y,z]):

V:= VectorField(< v[1](x,z,t),0,v[3](x,z,t)>);

NavierStokes:= diff(V,t) - nu*Laplacian(V) +1/rho* Gradient(p(x,z,t)) - VectorField(< 0,0,-g>)=0;

the velocity components are intriduced as following

v[1]:=(x,z,t)->diff(f(z),z)*exp(I*k*x+(-1)*I*omega*t);

v[2]:=(x,z,t)->0;

v[3]:=(x,z,t)->(-1)*I*k*f(z)*exp(I*k*x+(-1)*I*omega*t);

So the problem is 2D model so that v[1] and v[3] satisfy incompresibility condition. It is clear that substituting velocity components into NS leads to differential equations for f(z). The general form of f(z) is

f(z) = a1*cosh(k*z)+a2*sinh(k*z)+a3*cosh(kappa*z)+a4*sinh(kappa*z).

my problems are

1) apply v[1], v[3] and find f(z) with Maple. then apply boundary conditions to find coeffs a[i] with Maple

2) In addition, Substituting the f(z) into BCs leads to a linear homogeneous system of equations for the coefficients. The vanishing of the determinant of this system which is the condition for the existence of a nontrivial solution is interested. How can I do that?

3) f(z) is for the case that the bottom is z=0 and surface is z=h. in my case bottom is z=-h and surface is z=0. how to do this in the solution. I dont know how to apply it.

4) calculate pressure

this file is what I did.

NSE.mw

The function evalf(  ) will encounter a critical bug when doing the following evaluation:

restart;
P1 := 1007;
P2 := 1014;
P3 := 1014.1;
evalf(P2 - P1, 2);
evalf(P3 - P1, 2);

The first evalf( ) returns a correct value, while the second one returns a wrong value.
This is really unbelievable!

Buchberger function same as Basis function then how to make it as solver function?

is it the newly added y(y-1) be used in solver to find x ?

i find eliminate without y*(y-1) same solution as adding y*(y-1)

why premas and Reduce are different for calculating remainder h?

where is wrong in commented L and S polynomials ? LCM wrong?

with(Groebner):
with(ListTools):
with(combinat):

premas := proc(P,A, PRing)
local R, i, x;
R := P;
i := nops(A);
while i <> 0 do
 x := MainVariable(A[i], PRing);
 R := prem(R, A[i],x);
 i := i - 1:
od:
return R:
end proc:

Buchberger := proc(Fparam, PRing)
#Fparam := [x*y-x, -y+x^2]:
F := MakeUnique(Fparam):
GG := choose(F, 2):
G := F:
while GG <> [] do
f := GG[1][1]:
g := GG[1][2]:
GG := [seq(GG[i], i=2..nops(GG))]:
#L := lcm(TrailingTerm(f, PRing)[2],TrailingTerm(g, PRing)[2]):
#S := simplify(L/LeadingTerm(f, PRing)[2]*f - L/LeadingTerm(g, PRing)[2]*g);
S := SPolynomial(f, g, PRing);
#print("S",S);
#print("G",G);
# S reduce to G modulo h
#h := premas(S, G, PolynomialRing([x, y, z]));
h := Reduce(S, G, PRing, 'h');
#print("h",h);
if h = 0 then
h := []:
end if:
if h <> [] then
 GG := [op(GG), [SelectFirst(G), h]]:
 G := [op(G), h]:
end if:
od:
return G:
end proc:
sol := Buchberger([x*y-x, -y+x^2], plex(x, y));
factor(sol[nops(sol)]);
eliminate(sol,[x,y]);
eliminate([x*y-x, -y+x^2],[x,y]);
sol := Basis([x*y-x, -y+x^2], plex(x, y));
solve([x*y-x, -y+x^2]);
 

hello,

How I can remove this error for dsolve equation.

Thanks

2023.mw

Download 2023.mw

pointset := [A, [0,0], B, [0,v_B], C, [u_C, v_C], D, [x_D, y_D], O, [x_O, y_O]];
for i from 1 to nops(pointset)/2 do
print(i, i+1);
pointset[i] := pointset[i+1];
od:
how to Make A := [0,0] instead of pointset[1] 

Hi, 

In help page DocumentTools:-Layout:-Font, there is an example which shows how to inser a hyperlink in a Layout.

F := Font( "Some text", size=16, color=blue, style=:-Hyperlink ):
InsertContent(Worksheet(Group(Input(Textfield( F ))))):
 

When this id done, how can we activate this hyperlink ?
5I'm presently working with Maple 2015.2 under Mac OS Mojave)

Thanks in advance

how I can gain a function that it is fitting in these data in x and y and z?

please see the following figure.

this curve is a 3D diagram in three coordinates x,y and z.

Thanks

PLOTfitting.xls