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simultaneous animation of center of a circle movin...

Asked by: P M Dearing 15
December 19 2024
1  1

Given the center x1 of a circle in R^2 with radius d12, and a point p2 on the circle, so that d12=||p2-x1||, denote the points on the line segment from x1 to p2 as x1(t) = x1+t*v12, with t=0..d12, and v12 =( p2-x1)/d12.  I want to animate the points x1(t) moving along the line segment from x1 to p2 and the corresponding circles of decreasing radius, with center x(t) and radius d12-t, so that p2 remains on the circle.

I can animate the points along the line segment from x1 to p2 using ‘style=point, symbol=solidcircle’.

I would like to use plottools-circle, to plot the circles. I have also tried the following type commands for the circles of decreasing radius.

Plot([x1(1)+t*v12(1)+(d12-t)*cos(theta)*v12(1)+ (d12-t)*sin(theta)*u12(1), x1(2)+ +t*v12(2)+(d12-t)*d12*cos(theta)*v12(2)+(d12-t)*sin(theta)*u12(2), theta=0..2*PI]

where u12 is a unit vector orthogonal to v12.

I have not been able to combine the two plots into an animation. Thank you

Can I trust the diffrent engines of PolynomialSyst...

Asked by: Saalehorizontale 55
polynomial solvetools
December 18 2024
0  6

Hey Guys, 

I have to solve multiple system of equations under some restrictions given as inequalities. Sometimes solve is not able to find the result in houres so I tryd to break the problem in half. So in the first step I just want to solve my 8 polynomial equations with 8 variables and in a second step I want so take the solutions, bring them together with the set of inequalities and solve it again. Since also some sets of equations are to hard for the simple solve command I got the advice from people of this plattform to try PolynomialSystem with the diffrent engines. However I have the feeling they make misstakes and now Im not sure If I can trust my results. 

Attached you can find a file with an example. In the beginning I solve equations and restrictions together and there is a solutions. Then I tryd to solve only the equations with PolynomialSystem and the the four known engines and the eniges traditional and backsolve dont find the solution which as we saw before exist. When a soultions holds under restrictions it should always appear if I omit the restirctions. When I use the enige triade and groebner then the right solution is there. 
However in some other cases it feels the other way round.
So to me it looks like no matter which engine I take, I can never 100% trust my results. Did I something wrong? Whats the reason for those mistakes? Furthermore backsolve gives me 7 solutions, but solutions 2 and 7 are the same. I also recognized, that there is a diffrence between putting in the variable vars as a list or a set. What happens, if I dont specify which engine should be used?

I am happy about any advice. Thank you in advance.

Regards

Felix

> 

restart; equations := {-y*(m-p) = 0, ((-x-y+1)*k+x)*n+s*y-t = 0, (k-x-y)*t-k*p+y = 0, (-m+n+y)*x+m-1 = 0, -(x+y-1)*(p-t)*k+(-x-y+1)*t+x*p = 0, y^2+(-m-1)*y+1+x*(p-1) = 0, (-x-y+1)*t+(-m+1)*x+y*n+m-1 = 0, -k*n+s*x = 0}; restrictions := {0 < k, 0 < m, 0 < s, 0 < x, 0 < y, 0 < n+(t-1)*p, 0 < (m*y-1)*n+(1-p)*(m*x-m+1), 0 < (m*x-m-t+1)*p+m*y*(t-n), 1 < x+y, k < 1, m < 1, s < t, t < 1}; vars := indets(equations); evalf(solve(`union`(equations, restrictions), vars)); Sol_w := SolveTools:-PolynomialSystem(equations, vars); Sol_traditional := SolveTools:-PolynomialSystem(equations, vars, engine = traditional); nops([Sol_traditional]); Sol_backsolve := SolveTools:-PolynomialSystem(equations, vars, engine = backsolve); nops([Sol_backsolve]); Sol_triade_1 := SolveTools:-PolynomialSystem(equations, vars, engine = triade); nops([Sol_triade_1]); Sol_groebner := SolveTools:-PolynomialSystem(equations, vars, engine = groebner); nops([Sol_groebner])

{-y*(m-p) = 0, ((-x-y+1)*k+x)*n+s*y-t = 0, (k-x-y)*t-k*p+y = 0, (-m+n+y)*x+m-1 = 0, -(x+y-1)*(p-t)*k+(-x-y+1)*t+x*p = 0, y^2+(-m-1)*y+1+x*(p-1) = 0, (-x-y+1)*t+(-m+1)*x+y*n+m-1 = 0, -k*n+s*x = 0}

  

{k, m, n, p, s, t, x, y}

  

{k = 0.536796024e-1, m = .241141717, n = .54019322, p = .241141717, s = 0.35770767e-1, t = .4477103163, x = .8106439941, y = .6370663217}

  

{k = 1, m = m, n = 1, p = 0, s = 1, t = 1, x = 1, y = 0}, {k = 1, m = 1, n = 0, p = 1, s = t, t = t, x = 0, y = 1}, {k = k, m = 1, n = 0, p = 1, s = 1, t = 1, x = 0, y = 1}, {k = 1, m = 1, n = 0, p = 1, s = 0, t = 0, x = x, y = 1}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}, {k = 1/3, m = -1, n = 2, p = -1, s = 2/3, t = 2, x = 1, y = -1}, {k = -(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(2/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(16/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-7/9, m = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, n = (11/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(53/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(55/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(152/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-61/3, p = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, s = -(8/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(40/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(35/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2-(127/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+58/9, t = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(7/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+1/3, x = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+4/3, y = RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)}

  

{k = 1, m = m, n = 1, p = 0, s = 1, t = 1, x = 1, y = 0}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}, {k = k, m = 1, n = 0, p = 1, s = 1, t = 1, x = 0, y = 1}, {k = 1, m = 1, n = 0, p = 1, s = s, t = s, x = 0, y = 1}, {k = 1/3, m = -1, n = 2, p = -1, s = 2/3, t = 2, x = 1, y = -1}, {k = 1, m = 1, n = 0, p = 1, s = 0, t = 0, x = x, y = 1}

  

6

  

{k = 1, m = m, n = 1, p = 0, s = 1, t = 1, x = 1, y = 0}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}, {k = k, m = 1, n = 0, p = 1, s = 1, t = 1, x = 0, y = 1}, {k = 1, m = 1, n = 0, p = 1, s = s, t = s, x = 0, y = 1}, {k = 1/3, m = -1, n = 2, p = -1, s = 2/3, t = 2, x = 1, y = -1}, {k = 1, m = 1, n = 0, p = 1, s = 0, t = 0, x = x, y = 1}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}

  

7

  

{k = 1, m = 1, n = 0, p = 1, s = 0, t = 0, x = x, y = 1}, {k = 1, m = m, n = 1, p = 0, s = 1, t = 1, x = 1, y = 0}, {k = k, m = 1, n = 0, p = 1, s = 1, t = 1, x = 0, y = 1}, {k = 1, m = 1, n = 0, p = 1, s = t, t = t, x = 0, y = 1}, {k = -(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(2/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(16/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-7/9, m = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, n = (11/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(53/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(55/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(152/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-61/3, p = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, s = -(8/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(40/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(35/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2-(127/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+58/9, t = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(7/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+1/3, x = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+4/3, y = RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)}, {k = 1/3, m = -1, n = 2, p = -1, s = 2/3, t = 2, x = 1, y = -1}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}

  

7

  

{k = 1, m = m, n = 1, p = 0, s = 1, t = 1, x = 1, y = 0}, {k = 1, m = 1, n = 0, p = 1, s = t, t = t, x = 0, y = 1}, {k = k, m = 1, n = 0, p = 1, s = 1, t = 1, x = 0, y = 1}, {k = 1, m = 1, n = 0, p = 1, s = 0, t = 0, x = x, y = 1}, {k = 1/3, m = -1, n = 3, p = -1, s = 2, t = 2, x = 1/2, y = 0}, {k = 1/3, m = -1, n = 2, p = -1, s = 2/3, t = 2, x = 1, y = -1}, {k = -(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(2/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(16/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-7/9, m = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, n = (11/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(53/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(55/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(152/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-61/3, p = (4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(20/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(17/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, s = -(8/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+(40/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3+(35/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2-(127/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+58/9, t = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(7/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+1/3, x = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3-(8/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2+(4/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)+4/3, y = RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)}

  

7

 (1)
> 

evalf(allvalues({k = -(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4+2*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/9)+16*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/9)+(1/9)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-7/9, m = 4*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4*(1/3)-20*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/3)-17*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/3)+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, n = 11*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4*(1/3)-53*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/3)-55*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/3)+152*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)*(1/3)-61/3, p = 4*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4*(1/3)-20*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/3)-17*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/3)+21*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)-28/3, s = -8*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4*(1/9)+40*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/9)+35*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/9)-127*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)*(1/9)+58/9, t = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-4*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/3)-8*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/3)+7*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)*(1/3)+1/3, x = (1/3)*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^4-4*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^3*(1/3)-8*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)^2*(1/3)+4*RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)*(1/3)+4/3, y = RootOf(_Z^5-4*_Z^4-9*_Z^3+10*_Z^2+6*_Z-5)}))

{k = 0.536796024e-1, m = .241141717, n = .54019322, p = .241141717, s = 0.35770767e-1, t = .4477103163, x = .8106439941, y = .6370663217}, {k = .7943583912, m = 1.011543377, n = .16794280, p = 1.011543377, s = -.463558437, t = -.4040771797, x = -.287788440, y = .8837112597}, {k = -5.038767243, m = 3.694058367, n = 0.9373027e-1, p = 3.694058367, s = .299187114, t = 2.728412223, x = -1.578565716, y = 5.306977937}, {k = .2033642547, m = -26.40026363, n = -63.64948932, p = -26.40026363, s = 17.99511944, t = -2.562622110, x = -.719307867, y = -.8433142428}, {k = 2.542920564, m = -.546480183, n = 1.84762297, p = -.546480183, s = 1.244592174, t = .7905767063, x = 3.775017982, y = -1.984441276}

 (2)
 

NULL

Can_I_trust_the_diffrent_eniges_of_Polynomial_Systems.mw

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                             "(->)"

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December 17 2024
0  16

This is my first time working with plotting data from a matrix. However, with the help of a friends on MaplePrimes, I learned how to plot the data in both Maple and MATLAB. Despite this, I am having trouble with visualization. When I change the delta value, my function experiences vibrations or noise, which is clearly visible in the plot. But when I change delta, I encounter errors with my matrix data. How can I fix this problem? and there is any way for get better visualization by Explore ? also How show this vibration or noise in 2D?

> 

restart;
> 

randomize():
> 

local gamma;

gamma

 (1)
> 

currentdir(kernelopts(':-homedir'))
> 

NULL
> 

T3 := (B[1]*(tanh(2*n^2*(delta^2-w)*k*t/((k*n-1)*(k*n+1))+x)-1))^(1/(2*n))*exp(I*(-k*x+w*t+delta*W(t)-delta^2*t))

(B[1]*(tanh(2*n^2*(delta^2-w)*k*t/((k*n-1)*(k*n+1))+x)-1))^((1/2)/n)*exp(I*(-k*x+w*t+delta*W(t)-delta^2*t))

 (2)
> 

NULL
> 

params := {B[1]=1,n=2,delta=1,w=1,k=3 };

{delta = 1, k = 3, n = 2, w = 1, B[1] = 1}

 (3)
> 

NULL

insert numerical values

> 

solnum :=subs(params, T3);

(tanh(x)-1)^(1/4)*exp(I*(-3*x+W(t)))

 (4)
> 

CodeGeneration['Matlab']('(tanh(x)-1)^(1/4)*exp(I*(-3*x+W(t)))')

Warning, the function names {W} are not recognized in the target language

  

cg = ((tanh(x) - 0.1e1) ^ (0.1e1 / 0.4e1)) * exp(i * (-0.3e1 * x + W(t)));

  
> 

N := 100:

use Finance in:
  Wiener := WienerProcess():
  P := PathPlot(Wiener(t), t = 0..10, timesteps = N, replications = 1):
end use:
> 

W__points := plottools:-getdata(P)[1, -1]:
t_grid := convert(W__points[..,1], list):
x_grid := [seq(-2..2, 4/N)]:
> 

T, X := map(mul, [selectremove(has, [op(expand(solnum))], t)])[]:

ST := unapply(eval(T, W(t)=w), w)~(W__points[.., 2]):
SX := evalf(unapply(X, x)~(x_grid)):

STX := Matrix(N$2, (it, ix) -> ST[it]*SX[ix]);

_rtable[36893490640185799852]

 (5)
> 

opts := axis[1]=[tickmarks=[seq(k=nprintf("%1.1f", t_grid[k]), k=1..N, 40)]],
        axis[2]=[tickmarks=[seq(k=nprintf("%1.1f", x_grid[k]), k=1..N, 40)]],
        style=surface:

DocumentTools:-Tabulate(
  [
    plots:-matrixplot(Re~(STX), opts),
    plots:-matrixplot(Im~(STX), opts),
plots:-matrixplot(abs~(STX), opts)
  ]
  , width=60
)

"Tabulate"

 (6)
> 

MatlabFile := cat(currentdir(), "/ST2.txt"); ExportMatrix(MatlabFile, STX, target = MATLAB, format = rectangular, mode = ascii, format = entries)

421796

 (7)

NULL

Download data-analysis.mw

Area of octagon sought...

Asked by: Alfred_F 335
geometry
December 17 2024
3  4

A parallelogram is given in the Cartesian coordinate system. If the corner points of the parallelogram are connected to the midpoints of adjacent sides using lines, then the eight connecting lines form an octagon.
It must be proven that its area is one sixth of the parallelogram's area.

clarification on current status of odetest in Mapl...

Asked by: nm 11353
ode implicit differential-equations
December 16 2024
2  1

These two issues probably came up before, but I can't find where and when searching Maple primes.

So I thought to summarize the issues I see with odetest in one post, in the hope to get clarification on current status on these from the powers who know.

The first issue

The order in which odetest returns the answer. When odetest is called to check the ode and IC, as in 

the_status := odetest(sol,[ode,IC])

One would expect the_status to be a list, where the first entry tells if sol verifies the ode, and the second entry tells if sol verifies IC.

i.e. the order is the same as in the input. right? Since ode is first and IC is second in the input list.

But Maple sometimes mixes the order. See example 1 below. This makes it impossible to determine if the solution verifies the ode or IC,  when one of the entries in the_status is zero and the other is not, since order can be reversed sometimes.

Second issue:

When the solution is implicit, Maple gives invalid odetest result on the IC, unless one rewrites the solution using (lhs-rhs)(sol)=0.

i.e. move everything to the left side of the equation with RHS zero. This happens sometimes and when the solution is implicit.

I have thought this was fixed in current Maple, but it is not.  I remember this came up before, but can't find when and where.

Example 2 below shows an example.

Will these two issues hopefully be fixed in Maple 2025? Sometimes one forgets to rewrite the solution using (lhs-rhs)(sol)=0 and this results in false negative. 

Please see worksheet below. ps. I hope forum manager does not delete this question.

> 

interface(version);

`Standard Worksheet Interface, Maple 2024.2, Windows 10, October 29 2024 Build ID 1872373`

> 

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1838 and is the same as the version installed in this computer, created 2024, December 2, 10:11 hours Pacific Time.`

> 

libname;

"C:\Users\Owner\maple\toolbox\2024\Physics Updates\lib", "C:\Program Files\Maple 2024\lib"

> 

restart;
> 

 

Example 1: order of status from odetest is not same as order of input

 
> 

ode:=1+x*y(x)*(1+y(x)^2*x)*diff(y(x),x) = 0:
IC:=y(1) = 0:
sol:=x = 1/(3*exp(y(x)^2/2) - y(x)^2 - 2);

x = 1/(3*exp((1/2)*y(x)^2)-y(x)^2-2)

> 

#we see that odetest verifies the ode
odetest(sol,ode)

0

> 

#but when adding IC, 0 is now in second entry, instead of first

> 

odetest(sol,[ode,IC])

[(y(x)^4-y(x)^2*y(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))*(D(y))(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))+y(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))^3*(D(y))(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))-6*y(x)^2*exp((1/2)*y(x)^2)+3*exp((1/2)*y(x)^2)*y(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))*(D(y))(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))+4*y(x)^2-2*y(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))*(D(y))(-1/(y(x)^2-3*exp((1/2)*y(x)^2)+2))+9*exp(y(x)^2)-12*exp((1/2)*y(x)^2)+4)/(y(x)^2-3*exp((1/2)*y(x)^2)+2)^2, 0]

> 

#SHOULD NOT zero above be in first slot in the list instead of second slot??

> 

 

> 

 

Example 2. We must write the solution using (lhs-rhs)(sol)=0

 
> 

restart;

> 

ode:=1+x*y(x)*(1+y(x)^2*x)*diff(y(x),x) = 0:
IC:=y(1) = 0:
sol:=x = 1/(3*exp(y(x)^2/2) - y(x)^2 - 2);

x = 1/(3*exp((1/2)*y(x)^2)-y(x)^2-2)

> 

odetest((lhs-rhs)(sol)=0,[ode,IC])

[0, 0]

> 

#we see that now it verified both IC and sol

> 

 

> 

 

> 

 

 

Download issues_with_odetest_dec_16_2024.mw

Transform data in maple to Matlab or make analysis...

Asked by: salim-barzani 1575
matlab excel export
December 16 2024
1  8

I have a matrix for data analysis that I want to plot. Ideally, I would like to use Maple, but I’m struggling to create a well-designed plot suitable for submission to journals. Because of this, I’m considering transferring the data to Excel or constructing a 3D graph using MATLAB.

My question is: how can I transfer this data to Excel? The data is currently saved as a Notepad file, but I’m unsure how to convert it into an Excel format. I will upload a figure to show the data structure.

also in last runig program give me error which is (Error, (in ExportMatrix) permission denied

Thank you in advance for any help!

> 

restart;
> 

randomize():
> 

local gamma;

gamma

 (1)
 
> 

T3 := (B[1]*(tanh(2*n^2*(delta^2-w)*k*t/((k*n-1)*(k*n+1))+x)-1))^(1/(2*n))*exp(I*(-k*x+w*t+delta*W(t)-delta^2*t))

(B[1]*(tanh(2*n^2*(delta^2-w)*k*t/((k*n-1)*(k*n+1))+x)-1))^((1/2)/n)*exp(I*(-k*x+w*t+delta*W(t)-delta^2*t))

 (2)
> 

``
> 

params := {B[1]=1,n=2,delta=1,w=1,k=3 };

{delta = 1, k = 3, n = 2, w = 1, B[1] = 1}

 (3)
> 

``

insert numerical values

> 

solnum :=subs(params, T3);

(tanh(x)-1)^(1/4)*exp(I*(-3*x+W(t)))

 (4)
> 

CodeGeneration['Matlab']('(tanh(x)-1)^(1/4)*exp(I*(-3*x+W(t)))')

Warning, the function names {W} are not recognized in the target language

  

cg = ((tanh(x) - 0.1e1) ^ (0.1e1 / 0.4e1)) * exp(i * (-0.3e1 * x + W(t)));

  
> 

N := 100:

use Finance in:
  Wiener := WienerProcess():
  P := PathPlot(Wiener(t), t = 0..10, timesteps = N, replications = 1):
end use:
> 

W__points := plottools:-getdata(P)[1, -1]:
t_grid := convert(W__points[..,1], list):
x_grid := [seq(-2..2, 4/N)]:
> 

T, X := map(mul, [selectremove(has, [op(expand(solnum))], t)])[]:

ST := unapply(eval(T, W(t)=w), w)~(W__points[.., 2]):
SX := evalf(unapply(X, x)~(x_grid)):

STX := Matrix(N$2, (it, ix) -> ST[it]*SX[ix]);

_rtable[36893489786521178348]

 (5)
> 

opts := axis[1]=[tickmarks=[seq(k=nprintf("%1.1f", t_grid[k]), k=1..N, 40)]],
        axis[2]=[tickmarks=[seq(k=nprintf("%1.1f", x_grid[k]), k=1..N, 40)]],
        style=surface:

DocumentTools:-Tabulate(
  [
    plots:-matrixplot(Re~(STX), opts),
    plots:-matrixplot(Im~(STX), opts),
plots:-matrixplot(abs~(STX), opts)
  ]
  , width=60
)

"Tabulate"

 (6)
> 

MatlabFile := cat(currentdir(), "/ST2.txt"); ExportMatrix(MatlabFile, STX, target = MATLAB, format = rectangular, mode = ascii, format = entries)

Error, (in ExportMatrix) permission denied

  
 

 

Download data-analysis.mw

Christmas greeting is the solution...

Asked by: Alfred_F 335
geometry
December 15 2024
1  1

A gardener wants to spread 25 roses over an area so that there are 5 roses in each of 15 straight rows. The roses should be arranged rotationally symmetrically so that more than 3/4 of them are less than half as far from the center of symmetry as the outermost ones and that the center of symmetry itself remains unplanted. How is such an arrangement possible?

How to do change of variable in ode using z=g(x) ...

Asked by: nm 11353
ode differential-equations pdetools
December 14 2024
3  1

What is the correct syntax to do this change of variable from the text book:

The problem is that using PDEtools:-dchange, it wants the transformation to have form { old = new}, i.e. x=...  so I can not write  z=g(x) in the transformation. 

For example

ode:= diff(y(x),x$2)+diff(y(x),x)+y(x)=sin(x);
PDEtools:-dchange({z= g(x)},ode,known={x},unknown={z});

Error, (in dchange/info) missing a list with the new variables
And if I first solve for x so that I can write the transformation with x on left side, it still does not work

ode:= diff(y(x),x$2)+diff(y(x),x)+y(x)=sin(x);
PDEtools:-dchange({x=RootOf(g(_Z) - z)},ode,known={x},unknown={z});

Where RootOf(g(_Z) - z) was result of solve(z=g(x),x);

I am sure this can be done in Maple, I just do not know the right syntax to use with dchange.

Maple 2024.2

how to make limit give same result as eval, when D...

Asked by: nm 11353
eval limit dirac
December 13 2024
0  1

Is there a trick to make Maple give same result below when using eval and limit?  

Attached worksheet. This comes in context of solving ode  using Laplace. Initial conditions are at zero. And need to solve for the constant of integration. 

It works when using eval, since Dirac(t) becomes Dirac(0), but when using Limit, Dirac(t) becomes zero and the _C1 is lost. I was wondering if limit should also return Dirac(0) like eval?

> 

interface(version);

`Standard Worksheet Interface, Maple 2024.2, Windows 10, October 29 2024 Build ID 1872373`

> 

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1838 and is the same as the version installed in this computer, created 2024, December 2, 10:11 hours Pacific Time.`

> 

restart;
> 

e:=1/2*t+_C1*Dirac(t);

(1/2)*t+_C1*Dirac(t)

> 

eval(e,t=0)

_C1*Dirac(0)

> 

limit(e,t=0)

0

 

 

Download dirac_limit_dec_13_2024.mw

Bug report. Setting extended interface causes inte...

Asked by: nm 11353
integral typesetting physics
December 13 2024
2  3

In Latest Maple 2024.2, I found that when doing z:=%  where % is result on integration, causes internal error 

          Error, unexpected result from Typesetting

But when the interface is set to standard, no such error.

This not only happen in worksheet, but also when code is run in command line!

Worksheet below.

> 

interface(version);

`Standard Worksheet Interface, Maple 2024.2, Windows 10, October 29 2024 Build ID 1872373`

> 

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1837 and is the same as the version installed in this computer, created 2024, December 2, 10:11 hours Pacific Time.`

Example using extended

 
> 

restart;

> 

interface(typesetting=extended):

> 

int(exp(-int(b(t),t))*t^4*csc(t)^2,t);

int(exp(-(int(b(t), t)))*t^4*csc(t)^2, t)

> 

z:=%;

Error, (in Risch:-Norman) too many levels of recursion

` `

Error, unexpected result from Typesetting

> 

 

Example using standard

 
> 

restart;

> 

interface(typesetting=standard):

> 

int(exp(-int(b(t),t))*t^4*csc(t)^2,t);

int(exp(-(int(b(t), t)))*t^4*csc(t)^2, t)

> 

z:=%;

int(exp(-(int(b(t), t)))*t^4*csc(t)^2, t)

> 

 

> 

 

Example using direct assignment also

 
> 

restart;

> 

interface(typesetting=extended):

> 

z:=int(exp(-int(b(t),t))*t^4*csc(t)^2,t);

Error, (in Risch:-Norman) too many levels of recursion

` `

Error, unexpected result from Typesetting

Download extended_interface_causes_internal_bug_dec_13_2024.mw

ps. also reported to Maple support

Better simplification and latex export...

Asked by: salim-barzani 1575
collect simplification latex
December 13 2024
0  12

I was rejected because the editor said my equation is too long. My question is: Is there a way to rewrite the equation in a more concise form? Additionally, is there a package in Maple that allows for automatic simplification or collection of terms without using specific commands? Any suggestions for addressing this issue would be appreciated.

> 

restart
> 

``
> 

eq3 := -6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*alpha[1]^2*alpha[0]^3*a[4]+(6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*alpha[1]^2*alpha[0]^2*a[3]+(4*(-(2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*lambda+4*mu^2))*alpha[1]^2*a[5]*alpha[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]+(3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*alpha[1]^2*alpha[0]*a[2]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]+(5*(-(2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*lambda+4*mu^2))*alpha[1]^4*alpha[0]*a[4]+(4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*alpha[1]^2*lambda*a[5]*alpha[0]-k^2*a[1]*beta[0]^2+10*beta[0]^2*alpha[0]^3*a[4]+6*beta[0]^2*alpha[0]^2*a[3]+3*beta[0]^2*alpha[0]*a[2]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2-(1/4)*lambda*beta[0]^2*a[1]-9*mu^2*alpha[1]^2*a[1]*(1/4)+3*mu*a[1]*alpha[0]*beta[0]*(1/2)+(1/4)*(3*(-(2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*lambda+4*mu^2))*alpha[1]^2*a[1]+(-(2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda))*lambda+4*mu^2)*alpha[1]^4*a[3]-w*beta[0]^2-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4] = 0

-k^2*a[1]*beta[0]^2+4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[5]*alpha[0]-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]-w*beta[0]^2-(9/4)*mu^2*alpha[1]^2*a[1]+6*beta[0]^2*alpha[0]^2*a[3]-(1/4)*lambda*beta[0]^2*a[1]+3*beta[0]^2*alpha[0]*a[2]+(3/4)*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[1]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2+10*beta[0]^2*alpha[0]^3*a[4]+(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*a[3]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(3/2)*mu*a[1]*alpha[0]*beta[0]-6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]+3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]*a[2]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]+5*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*alpha[0]*a[4]+10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^3*a[4]+6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^2*a[3]+4*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[5]*alpha[0] = 0

 (1)
> 

numer(lhs(3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]*a[2]+5*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*alpha[0]*a[4]+10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^3*a[4]+6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^2*a[3]+4*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[5]*alpha[0]-6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(3/2)*mu*a[1]*alpha[0]*beta[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]-w*beta[0]^2+4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[5]*alpha[0]-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4]+(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*a[3]+(3/4)*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[1]-k^2*a[1]*beta[0]^2+10*beta[0]^2*alpha[0]^3*a[4]+6*beta[0]^2*alpha[0]^2*a[3]+3*beta[0]^2*alpha[0]*a[2]-(9/4)*mu^2*alpha[1]^2*a[1]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2-(1/4)*lambda*beta[0]^2*a[1] = 0))*denom(rhs(3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]*a[2]+5*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*alpha[0]*a[4]+10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^3*a[4]+6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^2*a[3]+4*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[5]*alpha[0]-6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(3/2)*mu*a[1]*alpha[0]*beta[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]-w*beta[0]^2+4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[5]*alpha[0]-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4]+(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*a[3]+(3/4)*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[1]-k^2*a[1]*beta[0]^2+10*beta[0]^2*alpha[0]^3*a[4]+6*beta[0]^2*alpha[0]^2*a[3]+3*beta[0]^2*alpha[0]*a[2]-(9/4)*mu^2*alpha[1]^2*a[1]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2-(1/4)*lambda*beta[0]^2*a[1] = 0)) = numer(rhs(3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]*a[2]+5*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*alpha[0]*a[4]+10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^3*a[4]+6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^2*a[3]+4*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[5]*alpha[0]-6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(3/2)*mu*a[1]*alpha[0]*beta[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]-w*beta[0]^2+4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[5]*alpha[0]-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4]+(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*a[3]+(3/4)*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[1]-k^2*a[1]*beta[0]^2+10*beta[0]^2*alpha[0]^3*a[4]+6*beta[0]^2*alpha[0]^2*a[3]+3*beta[0]^2*alpha[0]*a[2]-(9/4)*mu^2*alpha[1]^2*a[1]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2-(1/4)*lambda*beta[0]^2*a[1] = 0))*denom(lhs(3*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]*a[2]+5*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*alpha[0]*a[4]+10*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^3*a[4]+6*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*alpha[0]^2*a[3]+4*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[5]*alpha[0]-6*lambda*beta[0]^2*alpha[1]^2*a[3]-2*lambda*beta[0]^2*a[5]*alpha[0]+6*mu*beta[0]*alpha[1]^2*a[2]+3*mu*beta[0]*a[5]*alpha[0]^2+(3/2)*mu*a[1]*alpha[0]*beta[0]-12*mu^2*alpha[1]^2*a[5]*alpha[0]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*k^2*a[1]*alpha[1]^2+(1/2)*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[1]-w*beta[0]^2+4*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*alpha[1]^2*lambda*a[5]*alpha[0]-30*lambda*beta[0]^2*alpha[1]^2*alpha[0]*a[4]-20*mu*beta[0]*lambda*alpha[1]^4*a[4]-7*mu*beta[0]*lambda*a[5]*alpha[1]^2+24*mu*beta[0]*alpha[1]^2*alpha[0]*a[3]+60*mu*beta[0]*alpha[1]^2*alpha[0]^2*a[4]+(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^4*a[3]+(3/4)*(-2*(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*lambda+4*mu^2)*alpha[1]^2*a[1]-k^2*a[1]*beta[0]^2+10*beta[0]^2*alpha[0]^3*a[4]+6*beta[0]^2*alpha[0]^2*a[3]+3*beta[0]^2*alpha[0]*a[2]-(9/4)*mu^2*alpha[1]^2*a[1]-(lambda*B[1]^2-lambda*B[2]^2-mu^2/lambda)*w*alpha[1]^2-(1/4)*lambda*beta[0]^2*a[1] = 0))

-40*lambda^3*B[1]^2*a[4]*alpha[0]*alpha[1]^4+40*lambda^3*B[2]^2*a[4]*alpha[0]*alpha[1]^4-8*lambda^3*B[1]^2*a[3]*alpha[1]^4+8*lambda^3*B[2]^2*a[3]*alpha[1]^4+40*lambda^2*B[1]^2*a[4]*alpha[0]^3*alpha[1]^2-40*lambda^2*B[2]^2*a[4]*alpha[0]^3*alpha[1]^2-4*k^2*lambda^2*B[1]^2*a[1]*alpha[1]^2+4*k^2*lambda^2*B[2]^2*a[1]*alpha[1]^2-16*lambda^3*B[1]^2*a[5]*alpha[0]*alpha[1]^2+16*lambda^3*B[2]^2*a[5]*alpha[0]*alpha[1]^2-80*lambda^2*mu*a[4]*alpha[1]^4*beta[0]+24*lambda^2*B[1]^2*a[3]*alpha[0]^2*alpha[1]^2-24*lambda^2*B[2]^2*a[3]*alpha[0]^2*alpha[1]^2+120*lambda*mu^2*a[4]*alpha[0]*alpha[1]^4-4*lambda^3*B[1]^2*a[1]*alpha[1]^2+4*lambda^3*B[2]^2*a[1]*alpha[1]^2+12*lambda^2*B[1]^2*a[2]*alpha[0]*alpha[1]^2-12*lambda^2*B[2]^2*a[2]*alpha[0]*alpha[1]^2-120*lambda^2*a[4]*alpha[0]*alpha[1]^2*beta[0]^2+24*lambda*mu^2*a[3]*alpha[1]^4+240*lambda*mu*a[4]*alpha[0]^2*alpha[1]^2*beta[0]-40*mu^2*a[4]*alpha[0]^3*alpha[1]^2+4*k^2*mu^2*a[1]*alpha[1]^2-28*lambda^2*mu*a[5]*alpha[1]^2*beta[0]-4*lambda^2*w*B[1]^2*alpha[1]^2+4*lambda^2*w*B[2]^2*alpha[1]^2-24*lambda^2*a[3]*alpha[1]^2*beta[0]^2+32*lambda*mu^2*a[5]*alpha[0]*alpha[1]^2+96*lambda*mu*a[3]*alpha[0]*alpha[1]^2*beta[0]+40*lambda*a[4]*alpha[0]^3*beta[0]^2-24*mu^2*a[3]*alpha[0]^2*alpha[1]^2-4*k^2*lambda*a[1]*beta[0]^2-8*lambda^2*a[5]*alpha[0]*beta[0]^2+7*lambda*mu^2*a[1]*alpha[1]^2+24*lambda*mu*a[2]*alpha[1]^2*beta[0]+12*lambda*mu*a[5]*alpha[0]^2*beta[0]+24*lambda*a[3]*alpha[0]^2*beta[0]^2-12*mu^2*a[2]*alpha[0]*alpha[1]^2-lambda^2*a[1]*beta[0]^2+6*lambda*mu*a[1]*alpha[0]*beta[0]+12*lambda*a[2]*alpha[0]*beta[0]^2+4*mu^2*w*alpha[1]^2-4*lambda*w*beta[0]^2 = 0

 (2)
> 

simplify(-40*lambda^3*B[1]^2*a[4]*alpha[0]*alpha[1]^4+40*lambda^3*B[2]^2*a[4]*alpha[0]*alpha[1]^4-8*lambda^3*B[1]^2*a[3]*alpha[1]^4+8*lambda^3*B[2]^2*a[3]*alpha[1]^4+40*lambda^2*B[1]^2*a[4]*alpha[0]^3*alpha[1]^2-40*lambda^2*B[2]^2*a[4]*alpha[0]^3*alpha[1]^2-4*k^2*lambda^2*B[1]^2*a[1]*alpha[1]^2+4*k^2*lambda^2*B[2]^2*a[1]*alpha[1]^2-16*lambda^3*B[1]^2*a[5]*alpha[0]*alpha[1]^2+16*lambda^3*B[2]^2*a[5]*alpha[0]*alpha[1]^2-80*lambda^2*mu*a[4]*alpha[1]^4*beta[0]+24*lambda^2*B[1]^2*a[3]*alpha[0]^2*alpha[1]^2-24*lambda^2*B[2]^2*a[3]*alpha[0]^2*alpha[1]^2+120*lambda*mu^2*a[4]*alpha[0]*alpha[1]^4-4*lambda^3*B[1]^2*a[1]*alpha[1]^2+4*lambda^3*B[2]^2*a[1]*alpha[1]^2+12*lambda^2*B[1]^2*a[2]*alpha[0]*alpha[1]^2-12*lambda^2*B[2]^2*a[2]*alpha[0]*alpha[1]^2-120*lambda^2*a[4]*alpha[0]*alpha[1]^2*beta[0]^2+24*lambda*mu^2*a[3]*alpha[1]^4+240*lambda*mu*a[4]*alpha[0]^2*alpha[1]^2*beta[0]-40*mu^2*a[4]*alpha[0]^3*alpha[1]^2+4*k^2*mu^2*a[1]*alpha[1]^2-28*lambda^2*mu*a[5]*alpha[1]^2*beta[0]-4*lambda^2*w*B[1]^2*alpha[1]^2+4*lambda^2*w*B[2]^2*alpha[1]^2-24*lambda^2*a[3]*alpha[1]^2*beta[0]^2+32*lambda*mu^2*a[5]*alpha[0]*alpha[1]^2+96*lambda*mu*a[3]*alpha[0]*alpha[1]^2*beta[0]+40*lambda*a[4]*alpha[0]^3*beta[0]^2-24*mu^2*a[3]*alpha[0]^2*alpha[1]^2-4*k^2*lambda*a[1]*beta[0]^2-8*lambda^2*a[5]*alpha[0]*beta[0]^2+7*lambda*mu^2*a[1]*alpha[1]^2+24*lambda*mu*a[2]*alpha[1]^2*beta[0]+12*lambda*mu*a[5]*alpha[0]^2*beta[0]+24*lambda*a[3]*alpha[0]^2*beta[0]^2-12*mu^2*a[2]*alpha[0]*alpha[1]^2-lambda^2*a[1]*beta[0]^2+6*lambda*mu*a[1]*alpha[0]*beta[0]+12*lambda*a[2]*alpha[0]*beta[0]^2+4*mu^2*w*alpha[1]^2-4*lambda*w*beta[0]^2 = 0, 'symbolic')

-40*(B[1]-B[2])*((a[4]*alpha[0]+(1/5)*a[3])*alpha[1]^2+(2/5)*a[5]*alpha[0]+(1/10)*a[1])*alpha[1]^2*(B[1]+B[2])*lambda^3+4*(-20*a[4]*beta[0]*alpha[1]^4*mu+(10*(B[1]^2-B[2]^2)*a[4]*alpha[0]^3+6*a[3]*(B[1]^2-B[2]^2)*alpha[0]^2+3*(B[1]^2*a[2]-B[2]^2*a[2]-10*a[4]*beta[0]^2)*alpha[0]-6*beta[0]^2*a[3]-7*a[5]*beta[0]*mu-(B[1]-B[2])*(B[1]+B[2])*(k^2*a[1]+w))*alpha[1]^2-2*(a[5]*alpha[0]+(1/8)*a[1])*beta[0]^2)*lambda^2+(120*(a[4]*alpha[0]+(1/5)*a[3])*mu^2*alpha[1]^4+(240*a[4]*beta[0]*alpha[0]^2*mu+32*(mu^2*a[5]+3*mu*a[3]*beta[0])*alpha[0]+24*beta[0]*mu*a[2]+7*mu^2*a[1])*alpha[1]^2-4*(-10*a[4]*beta[0]*alpha[0]^3+3*(-mu*a[5]-2*a[3]*beta[0])*alpha[0]^2+3*(-beta[0]*a[2]-(1/2)*mu*a[1])*alpha[0]+beta[0]*(k^2*a[1]+w))*beta[0])*lambda+4*alpha[1]^2*mu^2*(-10*a[4]*alpha[0]^3+k^2*a[1]-6*a[3]*alpha[0]^2-3*a[2]*alpha[0]+w) = 0

  

 

 

Error, (in collect) invalid input: collect uses a 2nd argument, x, which is missing

  
> 

Q1 := collect(%, {B__1, B__2})

-40*(B[1]-B[2])*((a[4]*alpha[0]+(1/5)*a[3])*alpha[1]^2+(2/5)*a[5]*alpha[0]+(1/10)*a[1])*alpha[1]^2*(B[1]+B[2])*lambda^3+4*(-20*a[4]*beta[0]*alpha[1]^4*mu+(10*(B[1]^2-B[2]^2)*a[4]*alpha[0]^3+6*a[3]*(B[1]^2-B[2]^2)*alpha[0]^2+3*(B[1]^2*a[2]-B[2]^2*a[2]-10*a[4]*beta[0]^2)*alpha[0]-6*beta[0]^2*a[3]-7*a[5]*beta[0]*mu-(B[1]-B[2])*(B[1]+B[2])*(k^2*a[1]+w))*alpha[1]^2-2*(a[5]*alpha[0]+(1/8)*a[1])*beta[0]^2)*lambda^2+(120*(a[4]*alpha[0]+(1/5)*a[3])*mu^2*alpha[1]^4+(240*a[4]*beta[0]*alpha[0]^2*mu+32*(mu^2*a[5]+3*mu*a[3]*beta[0])*alpha[0]+24*beta[0]*mu*a[2]+7*mu^2*a[1])*alpha[1]^2-4*(-10*a[4]*beta[0]*alpha[0]^3+3*(-mu*a[5]-2*a[3]*beta[0])*alpha[0]^2+3*(-beta[0]*a[2]-(1/2)*mu*a[1])*alpha[0]+beta[0]*(k^2*a[1]+w))*beta[0])*lambda+4*alpha[1]^2*mu^2*(-10*a[4]*alpha[0]^3+k^2*a[1]-6*a[3]*alpha[0]^2-3*a[2]*alpha[0]+w) = 0

 (3)
> 

latex(Q1)

-40 \left(B_{1}-B_{2}\right) \left(\left(a_{4} \alpha_{0}+\frac{a_{3}}{5}\right) \alpha_{1}^{2}+\frac{2 a_{5} \alpha_{0}}{5}+\frac{a_{1}}{10}\right) \alpha_{1}^{2} \left(B_{1}+B_{2}\right) \lambda^{3}+4 \left(-20 a_{4} \beta_{0} \alpha_{1}^{4} \mu +\left(10 \left(B_{1}^{2}-B_{2}^{2}\right) a_{4} \alpha_{0}^{3}+6 a_{3} \left(B_{1}^{2}-B_{2}^{2}\right) \alpha_{0}^{2}+3 \left(B_{1}^{2} a_{2}-B_{2}^{2} a_{2}-10 a_{4} \beta_{0}^{2}\right) \alpha_{0}-6 \beta_{0}^{2} a_{3}-7 a_{5} \beta_{0} \mu -\left(B_{1}-B_{2}\right) \left(B_{1}+B_{2}\right) \left(k^{2} a_{1}+w \right)\right) \alpha_{1}^{2}-2 \left(a_{5} \alpha_{0}+\frac{a_{1}}{8}\right) \beta_{0}^{2}\right) \lambda^{2}+\left(120 \left(a_{4} \alpha_{0}+\frac{a_{3}}{5}\right) \mu^{2} \alpha_{1}^{4}+\left(240 a_{4} \beta_{0} \alpha_{0}^{2} \mu +32 \left(\mu^{2} a_{5}+3 \mu  a_{3} \beta_{0}\right) \alpha_{0}+24 \beta_{0} \mu  a_{2}+7 \mu^{2} a_{1}\right) \alpha_{1}^{2}-4 \left(-10 a_{4} \beta_{0} \alpha_{0}^{3}+3 \left(-\mu  a_{5}-2 a_{3} \beta_{0}\right) \alpha_{0}^{2}+3 \left(-\beta_{0} a_{2}-\frac{\mu  a_{1}}{2}\right) \alpha_{0}+\beta_{0} \left(k^{2} a_{1}+w \right)\right) \beta_{0}\right) \lambda +4 \alpha_{1}^{2} \mu^{2} \left(-10 a_{4} \alpha_{0}^{3}+k^{2} a_{1}-6 a_{3} \alpha_{0}^{2}-3 a_{2} \alpha_{0}+w \right)
 = 0

  
 

NULL

Download coment.mw

Major deficiency in Physics[Vectors]; Distinct...

by: nmacsai 260 Maple 2024
vector basis physics
December 12 2024
0  0

Major deficiency in Physics[Vectors]; Distinct sets of basis vectors are not recognized!

You can't define vectors in alternative bases like: {\hat{i}',\hat{j}',\hat{k}'} or {\hat{i}_{1},\hat{j}_{2},\hat{k}_{3}}.

This deficiency has been around for a while. I have found other posts regarding this problem.

The deficiency greatly reduces the allowable calculations with Physics[Vector].

Are there any plans to fix this?

Here is my example which shows this deficiency in more detail.

physics_vectors_and_multiple_unit_vectors.mw
 

restart

NULL

NULL

with(Physics[Vectors])

[`&x`, `+`, `.`, Assume, ChangeBasis, ChangeCoordinates, CompactDisplay, Component, Curl, DirectionalDiff, Divergence, Gradient, Identify, Laplacian, Nabla, Norm, ParametrizeCurve, ParametrizeSurface, ParametrizeVolume, Setup, Simplify, `^`, diff, int]

 (1)

NULL

Crucial Deficiency in Physics[Vectors]

 

NULL

I can only guess the purpose of the Physics[Vectors] package from reviewing it's corresponding help documentation. My interpretation of the documentation leads me to believe that the package is best used for generating vector equation formulas in different coordinate bases of a SINGLE coordinate system.

 

This means one can easily generate position vector expressions such as:

 

r_ = _i*x+_j*y+_k*z

r_ = _i*x+_j*y+_k*z

(1.1)

Cylindrical Position Vector

 

The position vector in a cylindrical basis is given by:

 

r_ = ChangeBasis(rhs(r_ = _i*x+_j*y+_k*z), 2)

r_ = (x*cos(phi)+y*sin(phi))*_rho+(cos(phi)*y-sin(phi)*x)*_phi+z*_k

(1.1.1)

r_ = ChangeBasis(rhs(r_ = _i*x+_j*y+_k*z), 2, alsocomponents)

r_ = _k*z+_rho*rho

(1.1.2)

NULL

NULLNULLNULL

Spherical Position Vector

 

NULL

r_ = ChangeBasis(rhs(r_ = _i*x+_j*y+_k*z), 3)

r_ = (y*sin(phi)*sin(theta)+x*sin(theta)*cos(phi)+z*cos(theta))*_r+(y*sin(phi)*cos(theta)+x*cos(phi)*cos(theta)-z*sin(theta))*_theta+(cos(phi)*y-sin(phi)*x)*_phi

 (1.2.1)

r_ = ChangeBasis(rhs(r_ = _i*x+_j*y+_k*z), 3, alsocomponents)

r_ = r*_r

(1.2.2)

NULL

NULL

As is known from the vector analysis of curvilinear coordinate systems the basis vectors can depend on the coordinates in question.

 

In cylindrical, the basis vectors are

 

_rho = ChangeBasis(_rho, 1)

_rho = _i*cos(phi)+sin(phi)*_j

(1.2)

_phi = ChangeBasis(_phi, 1)

_phi = -sin(phi)*_i+cos(phi)*_j

(1.3)

and in spherical, the basis vectors are

 

_r = ChangeBasis(_r, 1)

_r = sin(theta)*cos(phi)*_i+sin(theta)*sin(phi)*_j+cos(theta)*_k

(1.4)

_theta = ChangeBasis(_theta, 1)

_theta = cos(theta)*cos(phi)*_i+cos(theta)*sin(phi)*_j-sin(theta)*_k

(1.5)

_phi = ChangeBasis(_phi, 1)

_phi = -sin(phi)*_i+cos(phi)*_j

(1.6)

NULL

NULL

NULL

Example of this Deficiency using Biot-Savart Law

 

NULL

Biot-Savart law can be used to calculate a magnetic field due to a current carrying wire. The deficiency in question can be observed by explicity constructing the integrand in the Biot-Savart integral defined below.

NULL

NULL

NULL

In electrodynamics, quantum mechanics and applied mathematics, it is common practice to define a position of observation by a vector `#mover(mi("r"),mo("&rarr;"))` and a position of the source responsible for generating the field by a vector diff(`#mover(mi("r"),mo("&rarr;"))`(x), x).

 

It is just as common to define the difference in these vectors as

 

l_ = r_-(diff(r(x), x))*_

l_ = r_-`r'_`

(1.3.1)

and thus

 

dl_ = dr_-(diff(dr(x), x))*_

dl_ = dr_-`dr'_`

(1.3.2)

as found in the integrand of the Biot-Savart integral.

NULL

It suffices to consider `#mover(mi("l"),mo("&rarr;"))` = `#mover(mi("r"),mo("&rarr;"))`-`#mover(mi("r'"),mo("&rarr;"))` in a cylindrical basis for this argument.

 

The observation position is:

 

`#mover(mi("r"),mo("&rarr;"))` = rho*`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`+z*`#mover(mi("k"),mo("&and;"))`

NULL

The source position is:

 

diff(`#mover(mi("r"),mo("&rarr;"))`(x), x) = (diff(z(x), x))*(diff(`#mover(mi("k"),mo("&and;"))`(x), x))+(diff(rho(x), x))*(diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x))

NULL

`#mover(mi("l"),mo("&rarr;"))` = `#mover(mi("r"),mo("&rarr;"))`-(diff(`#mover(mi("r"),mo("&rarr;"))`(x), x)) and `#mover(mi("r"),mo("&rarr;"))`-(diff(`#mover(mi("r"),mo("&rarr;"))`(x), x)) = z(x)*`#mover(mi("k"),mo("&and;"))`-(diff(z(x), x))*(diff(`#mover(mi("k"),mo("&and;"))`(x), x))+rho*`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`-(diff(rho(x), x))*(diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x))

NULL

The deficiency in question arises because MAPLE cannot define multiple unit vectors in distinct bases such as {`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`, diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x)} or {`#mscripts(mi("&rho;",fontstyle = "normal"),mn("1"),none(),none(),mo("&and;"),none(),none())`, `#mscripts(mi("&rho;",fontstyle = "normal"),mn("2"),none(),none(),mo("&and;"),none(),none())`}.  These pairs of unit vectors arise naturally, as shown above in Biot-Savart law.

NULL

If we look at `#mover(mi("&rho;",fontstyle = "normal"),mo("&circ;"))` and  diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&circ;"))`(x), x) generally, they look like:

NULL

`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))` = `#mover(mi("i"),mo("&and;"))`*cos(phi)+sin(phi)*`#mover(mi("j"),mo("&and;"))`

NULL

diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x) = (diff(`#mover(mi("i"),mo("&and;"))`(x), x))*cos(diff(phi(x), x))+sin(diff(phi(x), x))*(diff(`#mover(mi("j"),mo("&and;"))`(x), x))

NULL

If the bases vectors {`#mover(mi("i"),mo("&and;"))`, `#mover(mi("j"),mo("&and;"))`, `#mover(mi("k"),mo("&and;"))`} and {diff(`#mover(mi("i"),mo("&and;"))`(x), x), diff(`#mover(mi("j"),mo("&and;"))`(x), x), diff(`#mover(mi("k"),mo("&and;"))`(x), x)} are Cartesian and are not related related through rotations so that

NULL

"(i)*i' =(|i|)*|i'|*cos(0)=1"``NULL

NULL

"(j)*(j)' =(|j|)*|(j)'|*cos(0)=1"NULL

NULL

"(k)*(k)' =(|k|)*|(k)'|*cos(0)=1 "

NULL

and so,NULL

 

`#mover(mi("i"),mo("&circ;"))` = diff(`#mover(mi("i"),mo("&circ;"))`(x), x)

NULL

`#mover(mi("j"),mo("&circ;"))` = diff(`#mover(mi("j"),mo("&circ;"))`(x), x)

NULL

`#mover(mi("k"),mo("&circ;"))` = diff(`#mover(mi("k"),mo("&circ;"))`(x), x)

NULL

the radial unit vectors in cylindrical are then,

 

`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))` = `#mover(mi("i"),mo("&and;"))`*cos(phi)+sin(phi)*`#mover(mi("j"),mo("&and;"))`

NULL

diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x) = `#mover(mi("i"),mo("&and;"))`*cos(diff(phi(x), x))+sin(diff(phi(x), x))*`#mover(mi("j"),mo("&and;"))`

NULL

In typical problems, the anglular location of the observation point, φ, is distinct from the angular location of the source, diff(phi(x), x) and so under this condition, `#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))` <> diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x).

 

Consider the classic problem of the magnetic field due to a circular current carrying wire. Surely, the angular coordinate of one location of the current carrying wire  is different from the angular coordinate  of an observation point hovering above and off-axis on the other side of the current carrying wire. See figure below.

NULL

NULL

NULL

NULL

Therefore,

 

`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))` <> diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x)

NULL

NULL

What happens in MAPLE when you try to define a second distinct unit vector diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x)?

NULL

One can easily find `#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`.

NULL

_rho

_rho

(1.3.3)

NULL

NULLIf you try to define diff(`#mover(mi("&rho;",fontstyle = "normal"),mo("&and;"))`(x), x) ...

 

 

diff(_rho(x), x)

`_rho'`

(1.3.4)

So using a prime doesn't work.

NULL

You could try a numbered subscript...

`_&rho;__2`

_rho__2

(1.3.5)

but that doesn't work.

 

You could try an indexed unit vector...

NULL

_rho[2]

_rho[2]

(1.3.6)

which can be define but is not recognized by Physics[Vectors] since...

 

NULL

ChangeBasis(_rho[2], 1)

Error, (in Physics:-Vectors:-Identify) incorrect indexed use of a unit vector: _rho[2]

 

NULL

And so it's just not possible with the current implementation.

``

``

NULL

NULL


 

Download physics_vectors_and_multiple_unit_vectors.mw

 

 

How do i solve this system of differential equatio...

Asked by: DONTWORRYBEKABU 15
ode dsolve differential-equations
December 12 2024
2  1

I'm having trouble solving this system of differential equations. I haven't solved systems of differential equations before but i tried defining the system and then using dsolve, but it couldn't solve all the equations.

Hope you can help.

NULL

diff(Q1(t), t) = -k1*Q1(t)

 

diff(Q2(t), t) = k1*Q1+k3/Q2(t)-k2*Q2(t)-k4*Q2(t)

 

diff(Q3(t), t) = k4*Q2

 

diff(Q4(t), t) = k2*Q2-k3/Q2

 

NULL

Download System_Of_Differential_Equations.mw

Techniques for Simplifying Differential Equations...

Asked by: salim-barzani 1575
pde differential-equations
December 11 2024
0  0

I'm trying to transform a partial differential equation (PDE) into an ordinary differential equation (ODE) as demonstrated in the paper. However, I find some steps confusing and difficult to follow. The process often feels chaotic, and managing the complexity of the equations is overwhelming. Could you suggest an effective and systematic method to handle such transformations more easily?

> 

restart
> 

with(PDEtools)
> 

with(LinearAlgebra)
> 

NULL
> 

with(SolveTools)
> 

undeclare(prime)

`There is no more prime differentiation variable; all derivatives will be displayed as indexed functions`

 (1)
> 

declare(Omega(x, t)); declare(U(xi))

Omega(x, t)*`will now be displayed as`*Omega

  

U(xi)*`will now be displayed as`*U

 (2)
> 

tr := {t = tau, x = tau*c[0]+xi, Omega(x, t) = U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))}

{t = tau, x = tau*c[0]+xi, Omega(x, t) = U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))}

 (3)
> 

P1 := diff(Omega(x, t)^m, t)

Omega(x, t)^m*m*(diff(Omega(x, t), t))/Omega(x, t)

 (4)
> 

L1 := PDEtools:-dchange(tr, P1, [xi, tau, U])

(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*(-((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))*c[0]+I*U(xi)*(-k*c[0]+w+delta*(diff(W(tau), tau))-delta^2)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))/(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))

 (5)
 
> 

pde1 := I*(diff(Omega(x, t)^m, t))+alpha*(diff(Omega(x, t)^m, `$`(x, 2)))+I*beta*(diff(abs(Omega(x, t))^(2*n)*Omega(x, t)^m, x))+m*sigma*Omega(x, t)^m*(diff(W(t), t)) = I*gamma*abs(Omega(x, t))^(2*n)*(diff(Omega(x, t)^m, x))+delta*abs(Omega(x, t))^(4*n)*Omega(x, t)^m

I*Omega(x, t)^m*m*(diff(Omega(x, t), t))/Omega(x, t)+alpha*(Omega(x, t)^m*m^2*(diff(Omega(x, t), x))^2/Omega(x, t)^2+Omega(x, t)^m*m*(diff(diff(Omega(x, t), x), x))/Omega(x, t)-Omega(x, t)^m*m*(diff(Omega(x, t), x))^2/Omega(x, t)^2)+I*beta*(2*abs(Omega(x, t))^(2*n)*n*(diff(Omega(x, t), x))*abs(1, Omega(x, t))*Omega(x, t)^m/abs(Omega(x, t))+abs(Omega(x, t))^(2*n)*Omega(x, t)^m*m*(diff(Omega(x, t), x))/Omega(x, t))+m*sigma*Omega(x, t)^m*(diff(W(t), t)) = I*gamma*abs(Omega(x, t))^(2*n)*Omega(x, t)^m*m*(diff(Omega(x, t), x))/Omega(x, t)+delta*abs(Omega(x, t))^(4*n)*Omega(x, t)^m

 (6)
> 

NULL
> 

L1 := PDEtools:-dchange(tr, pde1, [xi, tau, U])

I*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*(-((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))*c[0]+I*U(xi)*(-k*c[0]+w+delta*(diff(W(tau), tau))-delta^2)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))/(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))+alpha*((U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m^2*((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^2/(U(xi)^2*(exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^2)+(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*((diff(diff(U(xi), xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-(2*I)*(diff(U(xi), xi))*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-U(xi)*k^2*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))/(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))-(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^2/(U(xi)^2*(exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^2))+I*beta*(2*(abs(U(xi))*exp(-Im(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^(2*n)*n*((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))*abs(1, U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m/(abs(U(xi))*exp(-Im(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))+(abs(U(xi))*exp(-Im(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^(2*n)*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))/(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))))+m*sigma*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*(diff(W(tau), tau)) = I*gamma*(abs(U(xi))*exp(-Im(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^(2*n)*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m*m*((diff(U(xi), xi))*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau))-I*U(xi)*k*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))/(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))+delta*(abs(U(xi))*exp(-Im(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^(4*n)*(U(xi)*exp(I*(-k*(tau*c[0]+xi)+w*tau+delta*W(tau)-delta^2*tau)))^m

 (7)
> 

``

``

 (8)

Download transform-pde-to-ode-hard_example.mw

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