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usage of rotation command - Printable Version

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usage of rotation command - Angus - 06-30-2014 09:09 AM


I tried to use the rotation command for 2-dimensional rotation of a vector. I ended up with 3 questions.

1) It seems the command only works with point() arguments. So rotation( point(0,0), 0.1, point(0,10) ) would rotate the vector [[0, 10]] around the origin.
Is it not possible to give vectors as arguments?

2) The geometry app is no 3d so far so rotation( point(0,0,0),...) gives Error:Bad argument value. Is there a way for rotating in the 3rd dimension? And do you plan to add a 3rd dimension to the geometry app?

3) While trying to use rotation() with vectors I noticed that rotation( [[0 0]],0.1,[[0 10]]) gives an Error (since it does seem to work with points only) but is rewritten as rotation( [[0 0]], 0.1, [0 [10]]). Is that a valid notation for the vector 0,10 ?

For further explanation: I would consider it a lot more productive to do calculations with vectors and call commands for vectors directly. vector<->point<->vector is at least a lot of typing or is there an elegant way to do such calculations? When doing cas calculations I would not tend to use the geometry app because I have vector data from previous calculations. Like in the example I just want to rotate one vector. Desireable in three dimensions.

RE: usage of rotation command - Angus - 07-11-2014 06:07 AM

I would like to push these questions. Before I place a related suggestion I need information about what is possible.
Are you happy with converting to point before using geometric commands? that is fine for the app, but in daily use or programs e.g. rotating a vector is easier, I think.

What do you think and what could be done? Is that xcas related or hp-code?