Perspective (graphical) on the horizon line. All lines parallel with the viewer's line of sight recede to the horizon towards this vanishing point. This is the standard "receding railroad tracks" phenomenon. A two-point drawing would have lines parallel to two different angles. Any number of vanishing points are possible in a drawing, one for each set of parallel lines that are at an angle relative to the plane of the drawing. Perspectives consisting of many parallel lines are observed most often when drawing architecture (architecture frequently uses lines parallel to the x, y, and z axes). Because it is rare to have
Parallel coordinates Parallel coordinates Parallel coordinates are a common way of visualizing high-dimensional geometry and analyzing multivariate data. To show a set of points in an "n"-dimensional space, a backdrop is drawn consisting of "n" parallel lines, typically vertical and equally spaced. A point in "n"-dimensional space is represented as a polyline with vertices on the parallel axes; the position of the vertex on the "i"-th axis corresponds to the "i"-th coordinate of the point. This visualization is closely related to time series visualization, except that it is applied to data where the axes do not correspond to points in time, and