Talk:Vector fields in cylindrical and spherical coordinates: Difference between revisions
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is it correct to specifically call out the time derivative in those descriptions? would it not be more accurate to call out the spatial derivatives? i.e., in cylindrical coord's, dr_hat/dtheta = theta_hat. aren't the time derivatives only collapsed chain rules of the spatial derivative transformations? (dr/dt = dr/dtheta * dtheta/dt = dtheta/dt * theta_hat) ? <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/64.203.249.10|64.203.249.10]] ([[User talk:64.203.249.10|talk]]) 01:22, 28 September 2007 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot--> |
is it correct to specifically call out the time derivative in those descriptions? would it not be more accurate to call out the spatial derivatives? i.e., in cylindrical coord's, dr_hat/dtheta = theta_hat. aren't the time derivatives only collapsed chain rules of the spatial derivative transformations? (dr/dt = dr/dtheta * dtheta/dt = dtheta/dt * theta_hat) ? <small>—Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/64.203.249.10|64.203.249.10]] ([[User talk:64.203.249.10|talk]]) 01:22, 28 September 2007 (UTC)</small><!-- Template:UnsignedIP --> <!--Autosigned by SineBot--> |
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== Comment by 65.95.78.112 == |
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COMMENT: I think the formula for φ is not correct as the ''arctan()'' function only provides values on the (-π/2;π/2) interval. As a result, I think the best is to adapt the calculation of φ to, for instance, each quadrant ([0;π/2), [π/2;π), [π;3π/2) and [3π/2;2π)). See comment in [[http://en.wikipedia.org/wiki/Spherical_coordinates]]. |
Revision as of 02:24, 14 February 2008
Predictably, there is a notation conflict. Given that the article on spherical coordinates would predictably end up getting written by mathematicians, while this one would predictably end up getting written by physicists (since mathematicians generally only use Cartesian coordinates), predictably the notations are different, causing confusion to anyone who clicks on spherical coordinates. The matter remains unresolved. Revolver 05:48, 28 August 2005 (UTC)
Description of φ in spherical coordinates
The description of φ says: "φ is the angle with the X-Z-plane". I would say "φ is the angle with the X-Z-plane with positive X" or something else, because otherwise the angle could be measured with a negative X, which gives a wrong angle. 80.32.129.34 12:06, 15 March 2007 (UTC)
Unit vector derivatives
is it correct to specifically call out the time derivative in those descriptions? would it not be more accurate to call out the spatial derivatives? i.e., in cylindrical coord's, dr_hat/dtheta = theta_hat. aren't the time derivatives only collapsed chain rules of the spatial derivative transformations? (dr/dt = dr/dtheta * dtheta/dt = dtheta/dt * theta_hat) ? —Preceding unsigned comment added by 64.203.249.10 (talk) 01:22, 28 September 2007 (UTC)
Comment by 65.95.78.112
COMMENT: I think the formula for φ is not correct as the arctan() function only provides values on the (-π/2;π/2) interval. As a result, I think the best is to adapt the calculation of φ to, for instance, each quadrant ([0;π/2), [π/2;π), [π;3π/2) and [3π/2;2π)). See comment in [[1]].