[数] 无定向的
... unordered partition 无序分拆 unoriented 无定向的 unperfect 不完全的 ...
无向的
... unorganic 无机的 unoriented 无向的 unoriginal 无独创性的 ...
方位不定的
... reorientation n. 再定位 unoriented a. 方位不定的 unoriginal a. 非原先的; 无独创精神的; 模仿的 ...
不定向的
... 不混合;离析 unmixing 不混溶组织 unmixing texture 不定向的 unoriented ...
In mathematics, orientation is a geometric notion that in two dimensions allows one to say when a cycle goes around clockwise or counterclockwise, and in three dimensions when a figure is left-handed or right-handed. In linear algebra, the notion of orientation makes sense in arbitrary dimensions. In this setting, the orientation of an ordered basis is a kind of asymmetry that makes a reflection impossible to replicate by means of a simple rotation. Thus, in three dimensions, it is impossible to make the left hand of a human figure into the right hand of the figure by applying a rotation alone, but it is possible to do so by reflecting the figure in a mirror. As a result, in the three-dimensional Euclidean space, the two possible basis orientations are called right-handed and left-handed (or right-chiral and left-chiral).The orientation on a real vector space is the arbitrary choice of which ordered bases are "positively" oriented and which are "negatively" oriented. In the three-dimensional Euclidean space, right-handed bases are typically declared to be positively oriented, but the choice is arbitrary, as they may also be assigned a negative orientation. A vector space with an orientation selected is called an oriented vector space, while one not having an orientation selected, is called unoriented.