Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

This is another problem I just found in Maple 2019.2 on windows 10. professional.

I wanted to close Maple, so did  File->Exit 

 

But Maple did nothing. It did not close.  Also Alt-F4 did not close Maple. I had to click on the little X on top right corner of the open window to close Maple.  

In earlier version this used to work to close Maple.

Do others see this as well?  To reproduce, simply start Maple, and do File->Exit.

Here is a movie also

 

This may be a bug.  In Maple 2019.0

plot3d(x^2+y^2)

Now grab the graphing window and drag to adjust it's size.  It doesn't adjust it's size until you let go of the mouse button.

If maple can auto discover derived equations, 

then most variable are unknown name which may or may not be physics variable.

so, how to guess which physics data suitable for these look like meaningless variable?

or these tools only visualize the relationship of existing known equations?

How to solve this DE with IC by using DTM.
D^m u(x,t)=u''(x,t)-u^2 (x,t), where n-1< m < n 

IC: u(x,0)=1+sin(x), and u'(x,0)=0

I have a problem for school that I need help with. 

Solve: by variation of parameters.

x3y’’’ – x2y’’ − 2xy’ + 6y = x2

Use any software, e.g. Maple, as an aid in computing roots of the auxiliary equation and the Wronskian-based determinants W, W1, W2, W3

I was able to hand calculate the roots as [m1 = 3, m2 = 2, m3 = -1]
 

NULL

with(VectorCalculus); Wronskian([x^3, x^2, 1/x], x, 'determinant')

Matrix(%id = 18446744078324919462), -12*x

(1)

with(VectorCalculus); Wronskian([0, x^2, 1/x], x, 'determinant')

Matrix(%id = 18446744078349556782), 0

(2)

with(VectorCalculus); Wronskian([x^3, 0, 1/x], x, 'determinant')

Matrix(%id = 18446744078266878782), 0

(3)

with(VectorCalculus); Wronskian([x^3, x^2, 0], x, 'determinant')

Matrix(%id = 18446744078331625094), 0

(4)

m3 := Matrix(3, 3, [0, x^2, 1/x, 0, 2*x, 1/x^2, x^2, 2, 2/x^3])

Matrix(%id = 18446744078385724822)

(5)

Determinant(m3, method = multivar)

Determinant(Matrix(%id = 18446744078385724822), method = multivar)``

(6)

roots(x^3-x^2-2*x+6, alpha, beta)

[]

(7)

``

solve(x^3-x^2-2*x+6 = 0, x)

-(1/3)*(71+9*58^(1/2))^(1/3)-(7/3)/(71+9*58^(1/2))^(1/3)+1/3, (1/6)*(71+9*58^(1/2))^(1/3)+(7/6)/(71+9*58^(1/2))^(1/3)+1/3+((1/2)*I)*3^(1/2)*(-(1/3)*(71+9*58^(1/2))^(1/3)+(7/3)/(71+9*58^(1/2))^(1/3)), (1/6)*(71+9*58^(1/2))^(1/3)+(7/6)/(71+9*58^(1/2))^(1/3)+1/3-((1/2)*I)*3^(1/2)*(-(1/3)*(71+9*58^(1/2))^(1/3)+(7/3)/(71+9*58^(1/2))^(1/3))

(8)

m3 := Matrix(3, 3, [0, x^2, 1/x, 0, 2*x, 1/x^2, 1/x, 2, 2/x^3])

Matrix(%id = 18446744078348970214)

(9)

Determinant(m3, method = multivar)

Determinant(Matrix(%id = 18446744078348970214), method = multivar)

(10)

``

m3 := Matrix(3, 3, [0, x^2, 1/x, 0, 2*x, 1/x^2, 1/x, 2, 2/x^3])

``

``


 

Download project_27.mw

 

 

 

 

I have just upgraded my laptop from Windows 7 to Windows 10.  On starting up Maple 2018,  I receive the attached message on screen.  This is after previously loading the worksheet successfully.   Today,  I am not able to do so.  I need to permanently register my firewall to allow Maple to run; can anyone help?

Melvin

 

I have a .mapleinit file that amongst other things sets libname so my own packages are accessible and can be loaded using with(). Imagine my surprise when I found that a maple program that ran half an hour ago on Maple2019 bombed when it did not find its package. Closer investigation indicates that maybe .mapleinit is only searched for in currentdir()??

The updated Maple is `Maple 2019.2, APPLE UNIVERSAL OSX, Oct 30 2019, Build ID 1430966`

The old one is gone :-(. It was Maple2019.0. I should add that on this system, Maple is installed on an administrator account that is not my user account (luckily I have access to that). I am running macOS 10.14.6 Mojave.

I verified my older Maples still work as before.

Has anyone else seen this behaviour?

Mac Dude.

Edit: I need to be more specific here: When I double-click a worksheet (.mw file) then currentdir() will be set to the directory the .mw file is in. This has been long-standing Maple behaviour. But then currentdir() does not cover the home directory where .mapleinit sits. As a result, a blank sheet finds my .mapleinit whereas my files (that habitually I open with double-click or drag-drop) do no longer run the .mapleinit file.

 

can anyone help me to calculate the exact  value of the eigenvalues of this matrix:
 

Download mat.mw

 

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

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])
 
 

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.

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

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

 

Hi guys, 

I have tried to create a loop to solve a set of two equations, but can't seem to get it working. My initial equations are given by;

 

nstar := (F, L, sigma) -> ceil((ln(k*F) - ln(c(L, sigma)*B))/ln(Phi(L, sigma)))

 

and 

 

i := (F, L, sigma) -> r*(1 - (G(L, sigma)*Phi(L, sigma))^nstar(F, L, sigma)*B/F)/(1 - G(L, sigma)^nstar(F, L, sigma))

 

in which both are based on further rather simple equations. To these I am trying to apply the proc function where I am trying to find which i makes borth the equations above work :

 

i := proc(F,L,sigma)  

local k :=0.01 ;  

local eps := 0.01 ;  

do while(eps>0.001)  

nstar:= (6)

i := (7)

eps:= i -k:

k=i:

end do;

k;

end proc;


Error, Got internal error in Typesetting:-Parse : "'_Inert_DELAYLESSTHAN' is not a valid inert form"
 

But as you see I am here getting a error which I have not managed to fix. Can anyone see where I might have gone wrong? Could this be done by solve or fsolve? If yes, then how (have tried it as well without succeding)?

First 72 73 74 75 76 77 78 Last Page 74 of 2097