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implemented internally by generating a set of parameters |
implemented internally by generating a set of parameters |
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for the parent type. |
for the parent type. |
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For example, the buoytrans coordinate system, which is |
For example, the buoytrans coordinate system, which is |
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a translation to the location where the buoy should be, |
a translation to the location where the buoy should be, |
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based on a |
based on a point in an anchor coordinate system. |
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This means that the buoy will move naturally when the |
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(Benja:) Example? Is rotation derived from affine? |
anchor point moves, instead of linearly interpolating. |
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However, the buoytrans function will never transform |
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in any way that's not representable as a pure translation. |
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Parent coordinate system |
Parent coordinate system |
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A coordinate system through which the coordinates, having |
A coordinate system through which the coordinates, having |
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been transformed by the child, are transformed:: |
been transformed by the child, are transformed:: |
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p_screen = parent(child(p)) |
p_screen = parent(child(p)), |
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(Benja says:) Where ``p`` is the original point (in child coordsys), |
where ``p`` is the original point (in child coordsys), |
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``child()`` is the transformation of the coordsys itself, |
``child()`` is the transformation of the coordsys itself, |
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``parent()`` is the transformation of the coordsys' parent, |
``parent()`` is the transformation of the coordsys' parent, |
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and ``p_screen`` is the final point in screen coordinates. |
and ``p_screen`` is the final point in screen coordinates. |
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All derived coordinate system types have exactly the same |
All derived coordinate system types have exactly the same |
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parent coordinate system(s) and interpretations as the |
parent coordinate system(s) and interpretations as the |
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parent coordinate system type. |
parent coordinate system transformations. |
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(Benja:) I don't understand this. Is 'parent coordinate |
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system type' the type of the parent coordsys or the |
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coordinate system type *this* coordinate system type |
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is derived from? |
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Currently all coordinate systems have only one parent. |
Currently all coordinate systems have only one parent. |
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The theoretical point here is that the parent coordinate |
The theoretical point here is that the parent coordinate |