MaplePrimes Questions

is there any library or tools to design index of Grassmannian and its k and n for Schubert use?

is there any library to relate poset with index of Grassmannian and its k and n for Schubert use

RandomMatrix(n, 1);

does not seem too work with Vectors of dimension d in elementwise multiplication ;/ Even though it is an nx1 matrix = an n vector.

This seems like a limitation maple!

 

RandomVector(n);

Does seem to work with Matrix and Vector.

Matrix(5,1)*~Vector(5);

Both have the same dimensions and should be possible to multiply them pointwise!

 

 

 

with(RegularChains);
R := PolynomialRing([x, y, z]);
p1 := x^2+5-2*x*z;
p2 := z^3*y+x*y^2;
p3 := -8*z^3+3*y^2;
F := [p1, p2, p3];
MainVariable(p1, PolynomialRing([x, y, z]));
MainVariable(p1, PolynomialRing([z, y, x]));
prem(p1, p2, x);
prem(p2, p1, z);
prem(p3, p2, y);
premcustom := proc(Fparam,Gparam, xparam)
local R, G, F, lcg, lcr, dr, dg:
R := Fparam:
G := Gparam:
F := Fparam:
if degree(G,xparam) = 0 then
 print("return 0"):
 return 0:
elif degree(F, xparam) < degree(G, xparam) then
 print("return R"):
 return R:
else
 lcg := coeff(G, xparam, degree(G, xparam)):
 dg := degree(G, xparam):
 while degree(R, xparam) > degree(G, xparam) do
  lcr := coeff(R, xparam, degree(R, xparam)):
  dr := degree(R, xparam):
  R := lcg * R - lcr * G * (x^(dr - dg)):
 od:
end if:
return R:
end proc:
coeff(p1, x, degree(p1, x));
coeff(p2, x, degree(p2, x));
prem(p1,p2,x);
prem(p2,p1,z);

premcustom(p1,p2,x);
premcustom(p2,p1,z);
 
why premcustom looping?
 
is this coeff(p1, x, degree(p1, x)); wrong ?
 
should this to get real coefficient in number instead of variable and how?
 
is there equivalent function as dprem?
 
with(diffalg):with(diffalg):
FlessThanG := proc(Fparam, Gparam, PRing)
F := Fparam:
G := Gparam:
if leader(F,PRing) < leader(G,PRing) or (leader(F,PRing) = leader(G,PRing) and degree(F, leader(F,PRing)) < degree(G, leader(G,PRing))) then
 return True:
else
 return False:
end if:
end proc:
dprem := proc(Fparam, Gparam, x, PRing)
local R, theta, thetax, thetaG, F, G;
F := Fparam:
G := Gparam:
R := F:
thetax := leader(G, PRing);
while FlessThanG(R, G, PRing) or FlessThanG(G, R, PRing) do
theta := leader(R, PRing);
R := prem(R, thetaG, theta)
od:
return R:
end proc:
R := differential_ring(ranking = [[x,y,r]], derivations = [t], field_of_constants=[m,l], notation = diff):
p1 := m*x[2] + r*x;
p2 := m*y[2] + r*y - g;
p3 := x^2 + y^2 - l^2;
dprem(p1, p3, x, R);
 
 
is x[2] = diff(x,t$2) in diffalg ?
 
if not how to write in this way?
 
i had defined constant
but got error
 
Error, (in DifferentialAlgebra:-Tools:-LeadingDerivative) unknown symbol (approx. error location: [m*x[2 --> ] <-- +r*x])
 
 

        Hello, everyone,I can not find a function that can do convolution, so if you know please tell me. Thanks!

 

what is the Taylor Series of

F(x,y+q,G(x+q,z) )

where x,y,z is variables and q is constant

Just a quick question, I know we can use "%" to obtain the las result in maple. what if I want to obtain the second last result? or in general the n-last result ? Thx

Hi, I'm trying to solve 1-D thermal equation defined below, but I end up with an error : Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {f(t, 1)}.

Could you please point out what am I doing wrong? Perhaps it's how I define the PDe or how I write the boundaries? Any help appreciated!

with(PDEtools)

PDE := cp*diff(T(t, r), t) - k_1*diff(diff(T(t, r), r), r) - k_1*diff(T(t, r), r)/r = Q;

all variables for now have dummy values of 1     

cp := 1;
k_2 := 1;
A := 1;
k_3 := 1;
k_4 := 1;
k_5 := 1;
k_6 := 1;
T_amb := 1;

                  

bcs_1 := eval(diff(T(t, r), r), r = 1) = k_3*T_amb;

bcs_2 := eval(diff(T(t, r), r), r = 0) = 0;
 
bcs_3 := eval(diff(T(t, r), t), t = 0) = 25;


PDE_all := {PDE, bcs_1, bcs_2, bcs_3};

sol := pdsolve(PDE_all, numeric);
Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {f(t, 1)}
 

Int not working with GlobalSolve why? It shows that bounds should be specified to all variable. but i have given bounds to all variables already. Thank you

How do I solve an overdetermined system of algebraic equations in Maple? solve command returns trivial solution for variables which are not actually trivial when I solve them by hand.

Hi all

When I solve using maple the first-order differential equation: diff(y,x)=0  for x in the closed interval [0,1] we obtain a constant function as a solution

but one can define the piecewise constant function see please the attached code

diff_piecewise.mw

why when we differentiate the piecewise function gives undefined derivative at point zero and a half.

Whats is the relationship between this example and Existence and uniqueness theorem for fist order ode

Many thanks

 

 

 

Hello everybody,

While i was trying to work on a physical math problem, a system of 4 integral equations is obtained. The right hand sides of these equations are known functions of r. The left hand sides contain double integrals with respect to lambda and t. i believe that an analytical determination of the 4 unknown functions f_1(t), f_2(t), f_3(t), and f_4(t) is far from being trivial, thus recourse to a numerical technique is necessary and indispensable.

 

i tried to express the unknown functions as series expansions in t and solve the resulting linear system of equations for the expansion coefficients, but unfortunately the coefficients are very large and the solution is strongly dependent on the number of coefficients. i was wondering whether someone here has some experience with such integral problems and is willing to assist and help. Any hint is highly appreciated.

 

i attach a Maple script including the equations.

Thank you,

 

>>>>>> Question.mw

I am trying to use Maple to solve a set of 5 equations, but cannot get a solution. Or there is no solution??

Any help? (Yes, the L function is a likelihood function and I am doing MLE for 5 variables..)


 

``

h := 4

4

(1)

k := Matrix(3, 4, {(1, 1) = 11.0, (1, 2) = 7.0, (1, 3) = 7.0, (1, 4) = 11.0, (2, 1) = 5.0, (2, 2) = 7.0, (2, 3) = 12.0, (2, 4) = 12.0, (3, 1) = 1., (3, 2) = 9.0, (3, 3) = 7.0, (3, 4) = 19.0})

Matrix(%id = 18446746279852723246)

(2)

A := Vector[row](3, {(1) = 6.0, (2) = 13.0, (3) = 18.0})

Vector[row](%id = 18446746279852713854)

(3)

B := Vector[row](3, {(1) = 3.0, (2) = 4.0, (3) = 4.0})

Vector[row](%id = 18446746279852763126)

(4)

"l(N1,M1,lambda,phi,r):=product((phi*(N1-'B[i]'+r*'A[i]'))^('k[i][1]')*(1/(2)*lambda*(M1-'A[i]'))^('k[i][2]'+'k[i][3]')*(1-phi*(N1-'B[i]'+r*'A[i]')-lambda*(M1-'A[i]'))^('k[i][4]')   ,i=1..(h-1))"

proc (N1, M1, lambda, phi, r) options operator, arrow, function_assign; product((phi*(N1-'B[i]'+r*'A[i]'))^'k[i][1]'*((1/2)*lambda*(M1-'A[i]'))^('k[i][2]'+'k[i][3]')*(1-phi*(N1-'B[i]'+r*'A[i]')-lambda*(M1-'A[i]'))^'k[i][4]', i = 1 .. h-1) end proc

(5)

``

``

NULL

fsolve({diff(ln(l(N1, M1, lambda, phi, r)), M1) = 0, diff(ln(l(N1, M1, lambda, phi, r)), N1) = 0, diff(ln(l(N1, M1, lambda, phi, r)), lambda) = 0, diff(ln(l(N1, M1, lambda, phi, r)), phi) = 0, diff(ln(l(N1, M1, lambda, phi, r)), r) = 0}, {M1, N1, lambda, phi, r}, N1 = 0 .. infinity, M1 = 0 .. infinity, lambda = 0 .. 1, phi = 0 .. 1, r = 0 .. 1)

``


 

Download PlayGround.mw

Please, is it possible to enlarge the vertices of a graph (DrawGraph in GraphTheory)? Thanks

Hi there, 

 

I am trying do to a solve procedure, so you can solve an equation using the following argument. 

Solution(eqn, value, var) which uses the embedded solve command. 

When is an integer it works fine with this code here. 

MySolution:=proc(xl::algebraic,is::integer, x::algebraic)
return solve(xl=is,x);
    end proc; 

However the problem arises when I will like to make it to recognize is a an decimal number aka float. 

MySolution:=proc(xl::algebraic,is::integer, x::algebraic)
    return solve(xl=is,x);
    if type(is,float) then
return solve(xl=is,x);
    end proc; 

Any idears on what I am doing wrong? 

Many thanks in advance and have a nice day.

I would like to find a fixed point of f^4 in tems of a and b. I define function as

 

I calculate f(f(f(f(x,y))))  and Iet f(f(f(f(x,y)))) = (x,y), then use the solve command as:

solve({b^4*(a*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)^2-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*b^2*(a*x-x^2-x*y)*x*y)*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*(a*x-x^2-x*y)*x*y = y, a*(a*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)^2-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*b^2*(a*x-x^2-x*y)*x*y)-(a*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)^2-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*b^2*(a*x-x^2-x*y)*x*y)^2-(a*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)^2-(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*b^2*(a*x-x^2-x*y)*x*y)*b^3*(a*(a*x-x^2-x*y)-(a*x-x^2-x*y)^2-(a*x-x^2-x*y)*b*x*y)*(a*x-x^2-x*y)*x*y = x}, {x, y})

My computer was freezing. How can I get my result. Thank you

 

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