>
|

|
Example 1.
Create a space of 2 independent variables and 2 dependent variables.
>
|
|
Define a vector X1 and compute its total and evolutionary parts totX1 and evolX1. Check that X1 = totX1 + evolX1.
J22 >
|
|
| (2.1) |
J22 >
|
|
| (2.2) |
J22 >
|
|
| (2.3) |
J22 >
|
|
| (2.4) |
Define a vector X2 and compute its total and evolutionary parts totX2 and evolX2. Check that X2 = totX2 + evolX2.
J22 >
|
|
| (2.5) |
J22 >
|
|
| (2.6) |
J22 >
|
|
| (2.7) |
J22 >
|
|
| (2.8) |
Define a vector X3 and compute its total and evolutionary parts totX3 and evolX3. Check that X3 = totX3 + evolX3.
J22 >
|
|
| (2.9) |
J22 >
|
|
| (2.10) |
J22 >
|
|
| (2.11) |
J22 >
|
|
| (2.12) |
Example 2.
In this example we illustrate the geometric interpretation of the evolutionary part of a projectable vector field.
First define a 3-dimensional bundle E over a two dimensional base. Define the base space M separately.
J22 >
|
![DGsetup([x, y], M)](/support/helpjp/helpview.aspx?si=6555/file05755/math243.png)
|
Define a vector field X4 and compute its evolutionary part evolX4. Define the projection Y4 of the vector field X4 onto the base manifold M.
E >
|
|
| (2.13) |
E >
|
|
| (2.14) |
E >
|
|
| (2.15) |
M >
|
|
| (2.16) |
Calculate the flow psi_t of Y4 and the flow Phi_t of X4.
M >
|
|
| (2.17) |
M >
|
|
| (2.18) |
Define a section sigma of E sending (x, y) to S(x, y).
E >
|
|
| (2.19) |
Calculate the induced flow on the space of sections.
M >
|
|
![sigma[t] := [x = (x*cos(t)+y*sin(t))*cos(t)-(-x*sin(t)+y*cos(t))*sin(t), y = (x*cos(t)+y*sin(t))*sin(t)+(-x*sin(t)+y*cos(t))*cos(t), u[] = S(x*cos(t)+y*sin(t), -x*sin(t)+y*cos(t))*exp(t)]](/support/helpjp/helpview.aspx?si=6555/file05755/math340.png)
| (2.20) |
M >
|
|
![[(x*cos(t)+y*sin(t))*cos(t)-(-x*sin(t)+y*cos(t))*sin(t), (x*cos(t)+y*sin(t))*sin(t)+(-x*sin(t)+y*cos(t))*cos(t), S(x*cos(t)+y*sin(t), -x*sin(t)+y*cos(t))*exp(t)]](/support/helpjp/helpview.aspx?si=6555/file05755/math347.png)
| (2.21) |
E >
|
|
| (2.22) |
Compare with the components of evolX4.
E >
|
|
| (2.23) |