MaplePrimes Questions

The Help page Physics/tensors-a complete guide states that spacetime metrics from Kramer et al. are referenced by chapter, section, and equation number, e.g., g_[[12, 16, 1]]. But there is no section 16 in Ch 12 and equations within each chapter are numbered sequentially without reference to section. By playing around it seems that in fact the first number is chapter, the second number is equation number, and the third number refers to subcases of the metric, when they are specified in the text. Is that correct?

Also, the output I get from say g_[[27, 27, 1]], or any other attempt  made, is just the metric, without any specification of the coordinates etc, which the Help pages susggest should be part of the output.

Hi!

The algorithm in this PDF is written in Fortran, but unfortunately I do not known this programming languaje (actually, I am not an "expert" in progamation).

Algoritmo_Fortram.pdf  [removed by moderator. © Institute of Mathematics AS CR, 1980]

 

https://dml.cz/handle/10338.dmlcz/103855

Could someone please write this algorithm in Maple? Or, at least, indicate me how to do.

Many thanks in advance for your comments.

 

 Good morning all.
Consider $A=[a_{i,j}]$, a $18\times 18$ matrix (for example); the integer entries are randomly chosen in $[[-5,5]]$ (for example). In general, $A$ has distinct eigenvalues.

I seek the eigen-elements of $B=Transpose(A^{-1})A$ with $10$ significand digits (for example); in general, $B$ is diagonalizable ($P^{-1}BP=D$, a diagonal complex matrix). I use the command $evalf(Eigenvectors(?))$.

Many randomized tests require working with hundreds of Digits. The worst one requires $629$ digits!! Moreover (in this test), when $Digits:=400$, the condition number of $P$ is $10^{118}$ and , with $Digits:=619$, the condition number drops to $376$.

I am surprised by this instability. In particular, this method seems to be unusable when $n=100$.
Does there exist a method (using maple) which allows to solve the problem without dragging behind me a multitude of digits ? (perhaps with iterations...)
Thanks in advance.

 

I want to to solve the system of partial differential equation using maple. I tried it but I am not able to solve it ... please help.

the equations are as follows

 


 

``

Finding transformation eqn between zero and harmonic with conformal1

``

 

restart

``

with(PDEtools)

sys := {(diff(Phi(r1, r2, r4), r1))^2-(diff(R(r1, r2, r4), r1))^2 = cos(T(r1, r2, r4))^2, (diff(Phi(r1, r2, r4), r2))^2-(diff(R(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, -(diff(R(r1, r2, r4), r2))*(diff(R(r1, r2, r4), r1))+(diff(Phi(r1, r2, r4), r2))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))+(diff(Theta(r1, r2, r4), r1))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2))+(diff(Theta(r1, r2, r4), r2))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2)) = 0, (R(r1, r2, r4)^2-Phi(r1, r2, r4)^2)*(diff(T(r1, r2, r4), r4))^2+2*(diff(Theta(r1, r2, r4), r4))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))^2-(diff(R(r1, r2, r4), r4))^2 = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2}

{(diff(Phi(r1, r2, r4), r1))^2-(diff(R(r1, r2, r4), r1))^2 = cos(T(r1, r2, r4))^2, (diff(Phi(r1, r2, r4), r2))^2-(diff(R(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, -(diff(R(r1, r2, r4), r2))*(diff(R(r1, r2, r4), r1))+(diff(Phi(r1, r2, r4), r2))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))+(diff(Theta(r1, r2, r4), r1))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2))+(diff(Theta(r1, r2, r4), r2))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2)) = 0, (R(r1, r2, r4)^2-Phi(r1, r2, r4)^2)*(diff(T(r1, r2, r4), r4))^2+2*(diff(Theta(r1, r2, r4), r4))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))^2-(diff(R(r1, r2, r4), r4))^2 = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2}

(1)

``

declare(Phi(r1, r2, r4), R(r1, r2, r4), T(r1, r2, r4), Theta(r1, r2, r4))

` Phi`(r1, r2, r4)*`will now be displayed as`*Phi

 

` R`(r1, r2, r4)*`will now be displayed as`*R

 

` T`(r1, r2, r4)*`will now be displayed as`*T

 

` Theta`(r1, r2, r4)*`will now be displayed as`*Theta

(2)

``

cases := [PDEtools:-casesplit({(diff(Phi(r1, r2, r4), r1))^2-(diff(R(r1, r2, r4), r1))^2 = cos(T(r1, r2, r4))^2, (diff(Phi(r1, r2, r4), r2))^2-(diff(R(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, -(diff(R(r1, r2, r4), r2))*(diff(R(r1, r2, r4), r1))+(diff(Phi(r1, r2, r4), r2))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))+(diff(Theta(r1, r2, r4), r1))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1)) = 0, -(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2))+(diff(Theta(r1, r2, r4), r2))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2)) = 0, (R(r1, r2, r4)^2-Phi(r1, r2, r4)^2)*(diff(T(r1, r2, r4), r4))^2+2*(diff(Theta(r1, r2, r4), r4))*(diff(T(r1, r2, r4), r4))+(diff(Phi(r1, r2, r4), r4))^2-(diff(R(r1, r2, r4), r4))^2 = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2}, caseplot)]

`========= Pivots Legend =========`

 

p1 = diff(R(r1, r2, r4), r2)

 

p2 = diff(Phi(r1, r2, r4), r1)

 

p3 = (diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^2

 

p4 = diff(Phi(r1, r2, r4), r2)

 

p5 = diff(R(r1, r2, r4), r1)

 

 

[`casesplit/ans`([diff(Theta(r1, r2, r4), r4) = (1/2)*(Phi(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-R(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-(diff(Phi(r1, r2, r4), r4))^2+(diff(R(r1, r2, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1))*(diff(Phi(r1, r2, r4), r2))^2-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1))*cos(T(r1, r2, r4))^2+(diff(Phi(r1, r2, r4), r1))*(diff(Phi(r1, r2, r4), r2))*(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2)))/(cos(T(r1, r2, r4))^2*(diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^4), diff(Theta(r1, r2, r4), r2) = (-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2))+(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2)))/cos(T(r1, r2, r4))^2, diff(diff(R(r1, r2, r4), r4), r4) = -R(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(R(r1, r2, r4), r4)), diff(R(r1, r2, r4), r1) = (diff(Phi(r1, r2, r4), r2))*(diff(Phi(r1, r2, r4), r1))/(diff(R(r1, r2, r4), r2)), (diff(R(r1, r2, r4), r2))^2 = (diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^2, diff(diff(Phi(r1, r2, r4), r4), r4) = -Phi(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(Phi(r1, r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(diff(Phi(r1, r2, r4), r2), r4) = -(diff(Phi(r1, r2, r4), r2))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(diff(Phi(r1, r2, r4), r2), r2) = 0, (diff(Phi(r1, r2, r4), r1))^2 = (diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0], [diff(R(r1, r2, r4), r2) <> 0, diff(Phi(r1, r2, r4), r1) <> 0]), `casesplit/ans`([diff(Theta(r1, r2, r4), r4) = (1/2)*(Phi(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-R(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-(diff(Phi(r1, r2, r4), r4))^2+(diff(R(r1, r2, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(R(r1, r2, r4), r4), r4) = -R(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(R(r1, r2, r4), r4)), diff(R(r1, r2, r4), r2) = 0, (diff(R(r1, r2, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(Phi(r1, r2, r4), r4), r4) = -Phi(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(Phi(r1, r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(Phi(r1, r2, r4), r1) = 0, (diff(Phi(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0], [diff(R(r1, r2, r4), r1) <> 0, diff(Phi(r1, r2, r4), r2) <> 0])]

(3)

``

map(length, cases)

[2101, 1405]

(4)

sys1 := op(1, cases[2])

[diff(Theta(r1, r2, r4), r4) = (1/2)*(Phi(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-R(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-(diff(Phi(r1, r2, r4), r4))^2+(diff(R(r1, r2, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(R(r1, r2, r4), r4), r4) = -R(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(R(r1, r2, r4), r4)), diff(R(r1, r2, r4), r2) = 0, (diff(R(r1, r2, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(Phi(r1, r2, r4), r4), r4) = -Phi(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(Phi(r1, r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(Phi(r1, r2, r4), r1) = 0, (diff(Phi(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0]

(5)

``

sys2 := op(1, cases[1])

[diff(Theta(r1, r2, r4), r4) = (1/2)*(Phi(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-R(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-(diff(Phi(r1, r2, r4), r4))^2+(diff(R(r1, r2, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1))*(diff(Phi(r1, r2, r4), r2))^2-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r1))*cos(T(r1, r2, r4))^2+(diff(Phi(r1, r2, r4), r1))*(diff(Phi(r1, r2, r4), r2))*(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2)))/(cos(T(r1, r2, r4))^2*(diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^4), diff(Theta(r1, r2, r4), r2) = (-(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2))+(diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r2)))/cos(T(r1, r2, r4))^2, diff(diff(R(r1, r2, r4), r4), r4) = -R(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(R(r1, r2, r4), r4)), diff(R(r1, r2, r4), r1) = (diff(Phi(r1, r2, r4), r2))*(diff(Phi(r1, r2, r4), r1))/(diff(R(r1, r2, r4), r2)), (diff(R(r1, r2, r4), r2))^2 = (diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^2, diff(diff(Phi(r1, r2, r4), r4), r4) = -Phi(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(Phi(r1, r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(diff(Phi(r1, r2, r4), r2), r4) = -(diff(Phi(r1, r2, r4), r2))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), diff(diff(Phi(r1, r2, r4), r2), r2) = 0, (diff(Phi(r1, r2, r4), r1))^2 = (diff(Phi(r1, r2, r4), r2))^2+cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0]

(6)

``

sys3 := op(2, cases[1])

[diff(R(r1, r2, r4), r2) <> 0, diff(Phi(r1, r2, r4), r1) <> 0]

(7)

``

sys4 := op(2, cases[2])

[diff(R(r1, r2, r4), r1) <> 0, diff(Phi(r1, r2, r4), r2) <> 0]

(8)

``

sol1 := dsolve(sys1, explicit)

(9)

``

constraint, subsystem := selectremove(has, sys1, T)

[diff(Theta(r1, r2, r4), r4) = (1/2)*(Phi(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-R(r1, r2, r4)^2*cos(T(r1, r2, r4))^4-(diff(Phi(r1, r2, r4), r4))^2+(diff(R(r1, r2, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(R(r1, r2, r4), r4))*(diff(R(r1, r2, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(Phi(r1, r2, r4), r4))*(diff(Phi(r1, r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(R(r1, r2, r4), r4), r4) = -R(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(R(r1, r2, r4), r4)), (diff(R(r1, r2, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(Phi(r1, r2, r4), r4), r4) = -Phi(r1, r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(Phi(r1, r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), (diff(Phi(r1, r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0], [diff(R(r1, r2, r4), r2) = 0, diff(Phi(r1, r2, r4), r1) = 0]

(10)

``

sol__subsystem := dsolve(subsystem)

{Phi(r1, r2, r4) = _F1(r2, r4), R(r1, r2, r4) = _F2(r1, r4)}

(11)

``

eval(constraint, sol__subsystem)

[diff(Theta(r1, r2, r4), r4) = (1/2)*(_F1(r2, r4)^2*cos(T(r1, r2, r4))^4-_F2(r1, r4)^2*cos(T(r1, r2, r4))^4-(diff(_F1(r2, r4), r4))^2+(diff(_F2(r1, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(_F2(r1, r4), r4))*(diff(_F2(r1, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(_F1(r2, r4), r4))*(diff(_F1(r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(_F2(r1, r4), r4), r4) = -_F2(r1, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(_F2(r1, r4), r4)), (diff(_F2(r1, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(_F1(r2, r4), r4), r4) = -_F1(r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(_F1(r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), (diff(_F1(r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0]

(12)

map(simplify, [diff(Theta(r1, r2, r4), r4) = (1/2)*(_F1(r2, r4)^2*cos(T(r1, r2, r4))^4-_F2(r1, r4)^2*cos(T(r1, r2, r4))^4-(diff(_F1(r2, r4), r4))^2+(diff(_F2(r1, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(_F2(r1, r4), r4))*(diff(_F2(r1, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(_F1(r2, r4), r4))*(diff(_F1(r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(_F2(r1, r4), r4), r4) = -_F2(r1, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(_F2(r1, r4), r4)), (diff(_F2(r1, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(_F1(r2, r4), r4), r4) = -_F1(r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(_F1(r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), (diff(_F1(r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0])

[diff(Theta(r1, r2, r4), r4) = (1/2)*((_F1(r2, r4)^2-_F2(r1, r4)^2)*cos(T(r1, r2, r4))^4-(diff(_F1(r2, r4), r4))^2+(diff(_F2(r1, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(_F2(r1, r4), r4))*(diff(_F2(r1, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(_F1(r2, r4), r4))*(diff(_F1(r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(_F2(r1, r4), r4), r4) = -cos(T(r1, r2, r4))*(_F2(r1, r4)*cos(T(r1, r2, r4))^3+2*(diff(_F2(r1, r4), r4))*sin(T(r1, r2, r4))), (diff(_F2(r1, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(_F1(r2, r4), r4), r4) = -cos(T(r1, r2, r4))*(_F1(r2, r4)*cos(T(r1, r2, r4))^3+2*(diff(_F1(r2, r4), r4))*sin(T(r1, r2, r4))), (diff(_F1(r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = sin(T(r1, r2, r4))^2, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0]

(13)

``

eval(constraint, sol__subsystem)

[diff(Theta(r1, r2, r4), r4) = (1/2)*(_F1(r2, r4)^2*cos(T(r1, r2, r4))^4-_F2(r1, r4)^2*cos(T(r1, r2, r4))^4-(diff(_F1(r2, r4), r4))^2+(diff(_F2(r1, r4), r4))^2)/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r1) = (diff(_F2(r1, r4), r4))*(diff(_F2(r1, r4), r1))/cos(T(r1, r2, r4))^2, diff(Theta(r1, r2, r4), r2) = -(diff(_F1(r2, r4), r4))*(diff(_F1(r2, r4), r2))/cos(T(r1, r2, r4))^2, diff(diff(_F2(r1, r4), r4), r4) = -_F2(r1, r4)*cos(T(r1, r2, r4))^4-2*cos(T(r1, r2, r4))*sin(T(r1, r2, r4))*(diff(_F2(r1, r4), r4)), (diff(_F2(r1, r4), r1))^2 = -cos(T(r1, r2, r4))^2, diff(diff(_F1(r2, r4), r4), r4) = -_F1(r2, r4)*cos(T(r1, r2, r4))^4-2*(diff(_F1(r2, r4), r4))*cos(T(r1, r2, r4))*sin(T(r1, r2, r4)), (diff(_F1(r2, r4), r2))^2 = -cos(T(r1, r2, r4))^2, sin(T(r1, r2, r4))^2 = -cos(T(r1, r2, r4))^2+1, diff(T(r1, r2, r4), r4) = cos(T(r1, r2, r4))^2, (diff(T(r1, r2, r4), r1))*sin(T(r1, r2, r4)) = 0, (diff(T(r1, r2, r4), r2))*sin(T(r1, r2, r4)) = 0, diff(T(r1, r2, r4), r1) = 0, diff(T(r1, r2, r4), r2) = 0]

(14)

``

``


 

Download Finding_transformation_eqn_between_zero_and_harmonic_with_conformal1.mw

Hi 

The integration in (F2) is not work properly.

My tyr is below:

restart:with(plots):
assume(d,real):

b:=-gamma1*tau0+I*tau0*Delta-2*a*(k-1)*xr:
a:=1+I*c;
c1:=sqrt(conjugate(a))/tau0:
c2:=0.5*((conjugate(b)/sqrt(conjugate(a)))):
lambda1:=2*(1-I*d)*(t-k1)/j+(1-I*d)^2:
lambda2:=t*(1-j)*k1/j+1/sqrt(2)*(1-I*d):
lambda3:=c1*(t-k1)/j+c1*(1-I*d)+c2:
J1:=sqrt(Pi)/sqrt(2)*(1-erf(lambda2)):
J1mod:=(Re(J1))^2+(Im(J1))^2:
g1:=0.5*sqrt(Pi)*tau0*exp(c2^2)*exp(-conjugate(a)*((k-1)*xr)^2)/(sqrt(conjugate(a))):

                       
F2:=-sqrt(2)*int(exp(-x^2)*erf(sqrt(2)*c1*x+lambda3),x=-lambda2..infty);
Warning,  computation interrupted
J2:=sum(g1*J1+g1*F2,k=1..1);
J2mod:=(((Re(J2))^2+(Im(J2))^2)):
W:= unapply(no*J1mod+Omega^2*J2mod,d):
Omega:=0.01:no:=1:Delta:=0:tau0:=1:c:=0:gamma1:=0:j:=1:k1:=0:t:=2*Pi:xr:=1:
P1:=plot(W,-50..50,axes=boxed,title=tit,color=black,font=[2,3,18],thickness=2,tickmarks=[3,2],titlefont=[SYMBOL,14],font=[1,1,18],linestyle=1);

Maple seems to have difficulty calculating this integral algebraically, although it seems not excessively complicated.

int( ((-A*omega*sin(omega*x+phi)*exp(-x/tau) - A*cos(omega*x+phi)*exp(-x/tau)/tau)^2 + 1)^(1/2), x=0..t ) assuming t>0, omega>0, tau>0, A>0

any suggestions to solve this integral?

thanks in advance

Hi,

Need your help to find the convergent solution of the attached problem.

Here is some information about parameters

(0 <= gamma <= 10,      0 <= rho & nu <= 200)

 

Arif_Ullah.mw
 

 

restart:

with(plots):

N:=6:

 

eq1 :=3*diff(f(eta),eta,eta,eta)+2*f(eta)*diff(f(eta),eta,eta)-(diff(f(eta),eta))^2;

3*(diff(diff(diff(f(eta), eta), eta), eta))+2*f(eta)*(diff(diff(f(eta), eta), eta))-(diff(f(eta), eta))^2

(1)

NULL

eq2 := 3*nu*diff(g(eta),eta,eta,eta)+2*g(eta)*diff(g(eta),eta,eta)-(diff(g(eta),eta))^2;

3*nu*(diff(diff(diff(g(eta), eta), eta), eta))+2*g(eta)*(diff(diff(g(eta), eta), eta))-(diff(g(eta), eta))^2

(2)

 

bc:=f(0) = 0, g(0) = 0, D(f)(0) = D(g)(0), D(D(f))(0) = -rho*nu*D(D(g))(0), D(D(f))(6) = 1, D(D(g))(N) = gamma;

f(0) = 0, g(0) = 0, (D(f))(0) = (D(g))(0), ((D@@2)(f))(0) = -rho*nu*((D@@2)(g))(0), ((D@@2)(f))(6) = 1, ((D@@2)(g))(6) = gamma

(3)

 

para:={nu=3, gamma=10};

{gamma = 10, nu = 3}

(4)

 

A1 := dsolve(subs(para,rho=2, {bc, eq1, eq2}), numeric,method = bvp[midrich],maxmesh=12500, output=array([seq( 0.01*i, i=0..100*N)])):

 

Error, (in dsolve/numeric/bvp) Newton iteration is not converging

 

pf1 := odeplot(A1, [[eta,diff(f(eta),eta), linestyle = 1, color = blue]], 0 .. N):

Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

 

 

pf2 := odeplot(A1, [[eta,diff(g(eta),eta), linestyle = 3, color = red]], 0 .. N):

Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

 

display({pf1,pf2}, axes = boxed,thickness=3,labels = [eta, "f' '"],labelfont = ["ROMAN", 22,Bold,Italic],axesfont = ["ROMAN", "ROMAN", 14,Bold],axis=[thickness=3]);

Error, (in plots:-display) expecting plot structures but received: {pf1, pf2}

 

NULL


 

Download Arif_Ullah.mw

 

Hi.

I am calculating an integral but I cannot get the result.
Can you help me.
I provide the file.

Tank you

Regards

integral_doubt.mw
 

restart

Rm := 2.5*10^(-3)

0.25e-2

(1)

Lm := 10^(-3)

1/1000

(2)

Ms := 10.7*10^5

0.11e7

(3)

ICMr := `assuming`([Ms*(int((z(t)-Z)*((Rm^2+r(t)^2+(z(t)-Z)^2)*(int(sqrt(1-4*r(t)*Rm*sin(phi)^2/((Rm+r(t))^2+(z(t)-Z)^2)), phi = 0 .. (1/2)*Pi))/((Rm-r(t))^2+(z(t)-Z)^2)-(int(1/sqrt(1-4*r(t)*Rm*sin(phi)^2/((Rm+r(t))^2+(z(t)-Z)^2)), phi = 0 .. (1/2)*Pi)))/(sqrt((Rm+r(t))^2+(z(t)-Z)^2)*r(t)), Z = -Lm .. 0))/(2*Pi)], [0 <= r(t), r(t) <= 2.5*10^(-3)])

 

(12)

``

subs([r(t) = 0.24e-2, z(t) = 0.1e-2], ICMr)

 

(13)
 

 

   

 


 

Download integral_doubt.mw

 I'm thinking about a question about counting the total number of Eulerian trails of following graphs . 

The Seven Bridges in Gonisburg lost one bridge due to war. 

G-e7

We looked up on Wikipedia to  add some details..

For the existence of Eulerian trails it is necessary that zero or two vertices have an odd degree; this means the Königsberg graph is not Eulerian. If there are no vertices of odd degree, all Eulerian trails are circuits. If there are exactly two vertices of odd degree, all Eulerian trails start at one of them and end at the other. A graph that has an Eulerian trail but not an Eulerian circuit is called semi-Eulerian.

It's easy to know that G-e7 is semi-Eulerian. So I want find all Eulerian trails. A simple attempt, found the following one in graph (Pink label).

I feel a little tricky dealing with this through Maple. The first reason is that the Maple graph theory package does not support parallel edges. Unfortunately, eand e6 are parallel edges of G-e7.

To take a step back, what if there are no parallel edges? For considering G-e7-e6.

There are some built-in commands related like FindEulerianPath , but can only find a Euler circuits.

 

 

 

 

Dear friends, please I would like to ask for your help with the following problem: 

I have to compute some linear programming calculations. I thought it would be a good idea to perform them employing a parallel code. However, much to my surprise, the parallel code is slower than the single-threaded one. I enclose a worksheet sketching both codes with an example. Would you please tell me what it could be wrong with my code? 

Many thanks for your help.EXAMPLES.mws 

In this figure, y axis scale is -1, -0.5,0,0.5,1.

i need that scale -1, -0.1, -0.2 -0.3......1

how to change?

 

Any could you please help me to write program using for loop of 

U(0, h, m)=0 for h=1 .. 10, m=0..10.?

Hi!

If I have a list of numbers e.g, data:=[0,12,0,7,5,3,7,10,0,0,9,3,2,5,0,6]

How do I get Maple to count the values bigger or equal to seven? [ans=5]

 

nnnnnnnnnnnn.mwHi everyone

I am a student. I have a problem with making matrix in maple. please help me.

this is the cod that I wrote.

 

I uploded my cod and the picture of matrix that I want to create.

thanks

 

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