one man

Alexey Ivanov

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     It is known that ODE boundary value problem is similar to the problem of solving systems of nonlinear equations. Equations are the boundary conditions, and the variables are the values of the initial data.
For example:

y '' = f (x, y, y '), 0 <= x <= 1,

y (0) = Y0, y (1) = Y1;

Where y (1) = Y1 is the equation, and Z0 is variable, (y '(0) = Z0).

     solve () and fsolve () are not directly suitable for such tasks. Directly should work the package of optimization in relation to a system of nonlinear equations. (Perhaps it has already been implemented in Maple.)
Personally, I am very small and unprofessional know Maple and cannot do it. Maybe there is someone who would be interested, and it will try to implement this approach to solving ODE boundary value problems?  

 For solving polynomial systems I used RootFinding[Isolate]. But after discussing the question http://www.mapleprimes.com/questions/211774-Roots-Of--Expz--1
I decided to compare Isolate and evalf(solve ([...], [...])). It seemed to me that solve some convenient. The only if in the equation there are integers as a real, they should be recorded with a decimal point. (For real solutions of this procedure should be used with (RealDomain).)  Examples:

SOLVE_ISOLATE.mw

I wonder why then the need Root Finding [Isolate]?

To check the point on the belonging to the segment I use the algorithm shown in the example. This is an example of intersection of the two segments in 2d. (We not check for parallelism.) We find the point of intersection of the corresponding lines and solve the equation f1 with respect to t and f2 with respect to tt. If 0 <= t <= 1, then the point belongs to the first segment, and if 0 <= tt <= 1 then the point belongs to the second segment.
(Similarly we can check point on the belonging to the segment in 3d.)
In the example point belongs to the second segment, but not the first. These segments do not intersect.
Question: Is there a function in Maple to find the intersection of the segments or to check on the belonging segment point, to make shorter?

segments_intersection.mw 

 

Can we get it in MapleSim, not in exactly this form, but in substance? (Not in Maple)
The line of intersection of surfaces:
(x1-0.5) ^ 4 + x2 ^ 4 + x 3 ^ 4-1. ^ 2 = 0.;
x1 ^ 2 + (x2-0.25) ^ 2 + x3 ^ 2-1. ^ 2 = 0.;
(Red) rotates about an axis oX3. During rotation, the line intersects with the fixed sphere ((0., 1.5, 0 .5); R = 1.725). One of the points of intersection is drawn in green. Green Dot and the center of the sphere connected to the blue segment.  In the sphere  of  fixed  trajectory of  the green point.
In other words, the geometric model  3d  cam mechanism and its kinematics.


 

 

Spiral on the cone. 







Yes, of course, in Maple.  The same source

 

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