Re: Distance point <=> straight line in space

Ben Bacarisse <ben.usenet@xxxxxxxxx> writes:
If there is any reason to transform your co-ordinate system, you might
want to shift and rotate the world so that p1 and p2 are on the z-axis
(say). Then all you distances are 2D from the origin. This feels
more expensive unless there is some other payoff to changing the
co-ordinate system.

Yes, you can save computing the z coordinate which doesn't matter for
the distance to the z axis.


[1] See, for example:
http://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html

--
__Pascal Bourguignon__ http://www.informatimago.com/

WARNING: This product warps space and time in its vicinity.
.

Relevant Pages

  • Re: BSG thoughts(spoilers for the most recent episode)
    ... >> The stars do not visibly shift positions over the earth's orbit because ... >> going to shift visibly. ... Parralax shift is how those distances are measured. ... the parsec (parallax arc-second) represents a larger distance. ...
    (rec.arts.sf.tv.babylon5.moderated)
  • Re: Distance point <=> straight line in space
    ... want to shift and rotate the world so that p1 and p2 are on the z-axis ... Then all you distances are 2D from the origin. ...
    (comp.programming)
  • Re: Rotate several elements
    ... rotate all elements and save the file as a pdf) I don't know much about the macro editor in Publisher and I cannot find the command which enables me to group elements. ... You might want to come over to the microsoft.public.publisher.programming group, where discussions about programming in Publisher are on-topic. ... Note that simply grouping and rotating will not preserve your layout properly - the distances from the top and left will become the distances from the bottom and right respectively. ... You can either do the math to work out what the new top and left should be, or create a rectangle the size of the page, group everything to it, rotate the group, ungroup, and delete the rectangle. ...
    (microsoft.public.publisher)
  • Re: WAS EINSTEIN A DUNCE?
    ... distances. ... Hold a pencil in front of you such that you are looking at its length. ... Now slowly rotate it. ... Now picture Space-Time as an open Space-Time. ...
    (sci.physics.relativity)
  • Re: Rotate several elements
    ... Is this a tent card style leaflet? ... to rotate the objects at all... ... properly - the distances from the top and left will become the distances ... everything to it, rotate the group, ungroup, and delete the rectangle. ...
    (microsoft.public.publisher)