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D.15.22.2 changeCoordinates
Procedure from library VecField.lib (see VecField_lib).
- Usage:
- changeCoordinates(vecField V, map psi), where psi is an algebra morphism
k[x1,...,xn]->k[y1,...,ym] expressing the new basis in terms of the old.
- Return:
- A new vecfield in the new coordinates.
- Note:
- the coordinate change necessitates inverting psi.
The inversion will be correct up to the precision of V.
Example:
| LIB "VecField.lib";
ring r = 0, (x, y, z),ds;
vector v = [-1,-1,-1];
VecField V = v;
V.precision = 4;
map phi = r, x-2y2+z3,2y+y3+z,z;
VecField W = changeCoordinates(V,phi);
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