Velocity, on the other hand, is a vector quantity : velocity in three-dimensional space is specified by three values; in a Cartesian coordinate system the values are the speeds relative to each coordinate axis.
22.
They are based on the idea that connections may only happen with the nearest neighbour of a point in each octant-that is, each of the eight regions of the plane delimited by the coordinate axis from this point and their bisectors.
23.
The coordinates of a point " P " are obtained by drawing a line through " P " perpendicular to each coordinate axis, and reading the points where these lines meet the axes as three numbers of these number lines.
24.
In Euclidean spaces of higher dimensions, more graphs may have greedy embeddings; for instance, " K " 1, 6 has a greedy embedding into three-dimensional Euclidean space, in which the internal node of the star is at the origin and the leaves are a unit distance away along each coordinate axis.
25.
:: As for your question'can we determine a shape from it's projections'- it might depend-the answer seems to be yes if we assume the shapes are all quadratics, . . . but much more complicated shapes might project as for example 3 circles along one set of coordinate axis ( suggesting a sphere )-but produce different shapes along a different set of coordinate axis . talk ) 12 : 39, 27 February 2008 ( UTC)
26.
:: As for your question'can we determine a shape from it's projections'- it might depend-the answer seems to be yes if we assume the shapes are all quadratics, . . . but much more complicated shapes might project as for example 3 circles along one set of coordinate axis ( suggesting a sphere )-but produce different shapes along a different set of coordinate axis . talk ) 12 : 39, 27 February 2008 ( UTC)
